how astronomical objects are named€¦ · dutchman gerardus mercator (1512-1594) on his 1551...

IntroductionAt the 1988 meeting in Rich-

mond, Virginia, the Inter-national Planetarium Society(IPS) released a statement ex-plaining and opposing the sell-ing of star names by privatebusiness groups. In this state-ment I reviewed the officialmethods by which stars arenamed. Later, at the IPS Exec-utive Council Meeting in 2000,there was a positive response tothe suggestion that as continuing Chair ofthe Committee for Astronomical Accuracy, Iprepare a reference article that describes notonly how stars are named, but how a widevariety of sky objects get their names. “HowAstronomical Objects Are Named” is theresult. I hope that this very long article mayserve as a helpful “one-stop” source ofanswers for most of your astronomy nomen-clature questions.

The professional astronomy group thatmakes official decisions about names of allastronomical objects is the InternationalAstronomical Union (IAU). Sky objects withnames established by long usage usually arerecognized by this group. Major committeesof the IAU are responsible for approving sys -t e m s that name sky objects as well as forapproving new proper names for some indi-vidual objects. There are specific IAU direc-tions for naming different categories ofobjects.

Like the IPS, the IAU has declared its com-plete dissociation with the commercial prac-tice of “selling” fictitious star names, wishingto make it unequivocally clear that any hintof association with these companies, whichtake in millions of dollars annually and haveoffices in many countries, is “patently falseand unfounded.” Similarly, governmentshave noted that one cannot sell land onother planets or their satellites.

Strongly making this point, Brian Mars-den, Director of the Minor Planet Center anda former Associate Director of the PlanetarySciences division at the Harvard-Smith-sonian Center for Astrophysics, declares thatthe business of having a star named for you

with the name registered in an ‘important’book “… is a scam. Astronomers don’t recog-nize those names. The Library of Congressdoesn’t recognize those names. They’re mis-leading the public. I’ve seen a few certificatesgiving the positions of the star — I’vechecked and there wasn’t a star there. Eitherthey’re making up star positions, or they’renot interpreting the charts correctly.” (D i s -cover, February, 2000, p. 72)

Planetarian Richard Pirko remarked onDome-L, “I never attempt to make the buyerlook like a fool. My boss, however, likes totell his classes that they can achieve the sameeffect [as purchasing a star] by walking intothe back yard, pointing to a star, and saying,‘I hereby name you Aunt Betty.’ You thencomplete the ceremony by removing fromyour wallet $45 and setting it on fire.”

This article will focus on the systems usedby astronomers to give accepted names tocelestial objects and object features as well asthe historical development of names for cat-egories of objects, individual objects, andobject features that now are in use. I haveadded anecdotal information to provideadditional background about the namingprocesses and to make the topic more inter-esting. Celestial nomenclature is a broad sub-ject with lots of opportunities to travel oninteresting side roads of information, so itwill take some time and distance (pages) toexplore.

The ConstellationsThroughout the world we find different

names for constellations, begun long ago, allinteresting and helpful to understanding the

use of the sky by the societies ofthe people that developed them.However, these different systemsare beyond the scope of this arti-cle; the discussion will be limitedto the system of constellationsused currently by astronomers inall countries. As we shall see, thehistory of the official constella-tions includes contributions andinnovations of people frommany cultures and countries.

The IAU recognizes 88 constel-lations, all originating in ancient times orduring the European age of exploration andmapping. Possibly, notes Owen Gingerich,the oldest constellation is Ursa Major, its use(in the Northern Hemisphere) circling theworld from an origin somewhere in Eurasia.The idea of a Bear for the Big Dipper, some-times with surrounding stars, was used bynatives of North America, who in turnmigrated from Asia. When Europeans metthe Native Americans, members of both cul-tures were surprised to find that the othergroup used the name of “bear” for these stars.Owen Gingerich suggests that the Bear con-stellation dates back to the Ice Ages.

Archaeoastronomer E. C. Krupp recentlyreviewed and analyzed a large body of litera-ture on the early development of the con-stellations in use today. I highly recommendKrupp’s article for a balanced look at differ-ent origin ideas including the “zone of avoid-ance” theory (pinpointing latitude whereunseen stars would have centered on thesouth celestial pole at certain times in theprecessional cycle) and Alexander Gursh-tein’s ideas on the development of Zodiacconstellations in sequential “quartet” groupsbeginning in about 5600 BC.

There are convincing records and argu-ments that Mesopotamia (areas of present-day Iran, Iraq, Northeastern Turkey, andSyria) was the site of origin for many of ourconstellations. Possibly the Lion (Leo), theBull (Taurus with the Pleiades), and the Scor-pion (Scorpius) , all Zodiac figures, wereamong the earliest, appearing in the fourthmillennium BC.

In ancient Greece, about 700 BC, the epic

6 Planetarian September 2004

How Astronomical Objects Are Named

Jeanne E. BishopWestlake Schools Planetarium

24525 Hilliard RoadWestlake, Ohio 44145 U.S.A.

bishop{at}@wlake.org Sept 2004

“What, I wonder, would the science of astrono-my be like, if we could not properly discrimi-nate among the stars themselves. Without theuse of unique names, all observatories, bothancient and modern, would be useful tonobody, and the books describing these thingswould seem to us to be more like enigmasrather than descriptions and explanations.”

– Johannes Hevelius, 1611-1687

poems of I l i a d and O d y s s e y, attributed toHomer, and Works and Days, attributed toHesiod, independently mention the GreatBear, Orion and the Pleiades. The asterism ofthe Pleiades was put forth as a separate con-stellation.

The astronomer Eudoxus (c . 390 BC-340BC) was the first Western writer to discussmany of the now-recognized constellationsof the Northern Hemisphere. We understandthat his presentation was given in two sepa-rate books, now lost, handbooks for use witha celestial globe showing these constella-tions. P h a e n o m e n a, a poem that Aratus ofSoli wrote in about 275 BC, shows us whatEudoxus must have described. Eudoxus andAratus identified 47 of our constellations,including “the Water” (now part of Aquar-ius). Other Greek works listing P h a e n o m e n aconstellations were summarized by Eratos-thenes (276 BC-194 BC) of Cyrene, famous forfinding the size of the Earth, in the third cen-tury BC.

Noting the times of these Greek writings,Krupp observes, “We encounter only sparseevidence for the constellations in the eighthcentury BC, but roughly 600 years later theyparade in full regalia and present themselvesas a complete set.” (Archaeoastronomy, V o l .XV, p. 45.)

Many researchers have tried to determinethe origin of the other Phaenomena c o n s t e l-lations, with wide agreement that mostcame from Mesopotamia. Studies whichincorporate the “zone of avoidance” theoryassume that the constellations were createdin one place at one time. Since each studyconcludes that P h a e n o m e n a c o n s t e l l a t i o n soriginated at a latitude/epoch (or place/time)combination that is somewhat differentfrom the others, these studies do not identifyour constellations’ roots.

Krupp says that we should not assumethat all the new constellations in P h a e n o -mena were created abruptly at the same loca-tion. Based on all available evidence, and thelack of data showing otherwise, he believes itlikely that an elaborate constellation systemwhich led to P h a e n o m e n a c o n s t e l l a t i o n sdeveloped when three things existed: amotive (reference for motions of the Moonand planets), a means (instruments and liter-acy), and an opportunity (social organiza-tion comparable to a kingship that supportstime, training, and resources for specialists).In a central situation with these features,newly-created constellations were fused toimported ones, sky figures that had beendevised in other places at other times. A like-ly candidate for the first major creator-syn-thesizers of our constellations was the Meso-potamian Sumerian culture. SubsequentMesopotamian kingship cultures may haveadded constellations with different origins

to the Sumerian constellation core. How the majority of Phaenomena constel-

lations made their way to Greece also isuncertain. The Minoans, a maritime groupwho moved between the Middle East andthe Mediterranean, may have learned theconstellations directly from Mesopotamians,used them for their navigation, and passedthem along to Egypt and Greece. Alterna-tively, Krupp thinks that it is just as plausiblefor Anatolia, especially Ionia on the westernshore of the Mediterranean and a place nearEudoxus’ home city of Cyzicus, to haveserved as main movers. Ionia was a wealthy,intellectual region, possessing excellent tradeconnections. The Minoans still may havehad a part in constellation distribution,adopting, adapting and transmitting themafter they finally reached Crete.

Ptolemy’s book was the most crucialinstrument for transmitting the Mesopo-tamian constellations to later generations.The set of figures described by Ptolemy inSyntaxis in the second century AD is thefoundation of our constellation system. Weknow Ptolemy’s work by the title A l m a g e s t(“the great book”). Syntaxis was translatedinto Arabic by Thabit ibn Qurra in the ninthcentury. The Ptolemaic constellations werekept vibrant in the Middle East while Europewas climbing out of a Dark Age. The Islamicscholar Al-Rahman Al-Sufi (903-986 AD.)identified 48 constellations in Treatise on theS t a r s , his version of the A l m a g e s t. Al-Suficombined Babylonian, Indian, and Bedouintraditions, drawing beautiful figures aroundthe stars identified by Ptolemy. For example,we see a camel by a woman in Al-Sufi’s repre-sentation of Cassiopeia. Al-Sufi’s book wasvery influential in both the Islamic area andin Christian Europe. A Latin versionappeared in 1270, and an Italian translationwas made in 1341.

New constellations were added by Euro-peans as their ships ranged to southern lati-tudes. And empty spaces in the northerncelestial sphere that had not yet receivednames, called by the Greek name of a m o r -p h o t o i, the “unformed” or “unshaped,” werefilled in. All constellations that were addedduring this post-Renaissance period are con-sidered “modern.” Many fell into disuse, butmany others were fused permanently withthose in Ptolemy’s list.

With the posthumous publication of his1602 star catalogue, Danish astronomerTycho Brahe (1546-1601) was influential inpopularizing two constellations engraved byDutchman Gerardus Mercator (1512-1594) onhis 1551 celestial globe. They were ComaBerenices (which Mercator called Cincinnis),once part of Leo, and Antinous, which was asection of Aquila. It is likely that Mercatorborrowed these figures from a globe printed

in Cologne by Caspar Vopel (1511-1561) fif-teen years before, developed in turn frommuch older ideas. Tycho promoted bothconstellations, Antinous and Coma Bere-nices, but Antinous did not last.

Between 1596 and 1603, twelve more con-stellations were added by two Dutch naviga-tors who observed in the Southern Hemi-sphere. Pieter Dirkszoon Keyser (?-1595) andFrederick de Houtman (c. 1571-1627) were in-structed by Dutch cartographer PetrusPlancius (1552-1622) to make and recordobservations while they were on southernvoyages. In an unexpected venue, a dictio-nary of Malay terms he published in 1603,Keyser added an appendix of 303 stars and 12new constellations visible from the SouthernHemisphere: Chamaeleon, Dorado, Grus,Hydrus, Indus, Musca, Pavo, Phoenix,Triangulum, Tucana, and Volans. Planciusinvented three constellations of his ownwhich are used today: Columba (from starsPtolemy had listed as surrounding CanisMajor), Monoceros, and Camelopardalis.

Johannes Hevelius (1611-1687) of Poland,who modeled his astronomy work on that ofTycho Brahe, slipped seven more constella-tions among the growing number, closingthe a m o r p h o t o i regions. In Hevelius’ 1690posthumously-published star atlas we dis-cover Canes Venatici, Lacerta, Leo Minor,Lynx, Scutum, and Vulpecula. Scutum wasintroduced as Scutum Sobieski, “shield ofSobieski.” Sobieski was King John III ofPoland (1624-1696) who fought hordes ofTurks that invaded Europe. Four constella-tions introduced by Hevelius which did notsurvive were Cerberus, Mons Marinalis,Musca, and Triangulum Minor. (Note thatMusca already was a name for a Southernconstellation.) In his Firmamentum Sobiesci -a n u m, Hevelius drew his constellation fig-ures with backs turned, as if they are lookingtoward the center of a celestial globe. Manycelestial cartographers had used this tech-nique in the golden age of the celestial atlas,beginning with Johann Bayer’s U r a n o m e t r i aof 1603, but Hevelius was the last to employit in a major star atlas.

Nicolas Louis de Lacaille (1713-1762) sailedto South Africa and established an observa-tory beneath Table Mountain at Cape Town.When Lacaille returned to France in 1754,after three years of observations, he pro-posed fourteen new constellations to theFrench Royal Academy of Science. Publishedin 1756, all of them were accepted and con-tinue to be used today: Antlia, CaelumSculptorium (Caelum), Circinus, FornaxChimiae (Fornax), Horologium, Mensa,Microscopium, Norma, Equuleus Pictoris(Pictor), Pyxis, Reticulum, Octans, AparatusSculptoris (Sculptor) , and Telescopium.Lacaille named Mensa, meaning “table,” in

September 2004 Planetarian 7

honor of Cape Town’s Table Mountain, siteof his southern observatory. If Ptolemycould come forward from his time in the sec-ond century AD, no doubt he would be puz-zled by the many instrument names foundin Lacaille’s list. Lacaille introduced anotherchange which persisted, a division of ArgoNavis into the separate constellations ofCarina, Puppis, and Vela.

After Hevelius and Lacaille, many astron-omers and cartographers tried to add constel-lations. But their ideas did not last.

Before Hevelius and Lacaille, in 1627,Julius Schiller (1596-1805) had substitutedChristian and Judaic names and figures fortraditional constellations. Schiller respondedto arguments made by theologians duringthe Middle Ages that the sky was filled withpagan images. One sees Schiller’s religiousconstellations in two beautiful planispheresof Celestial Atlas (1661) by Andreas Cellarius(c . 1596-1665). Following Schiller’s lead,Cellarius replaced the zodiacal constellationswith 12 apostles and Argo Navis with Noah’sArk. Cellarius also produced planispheres ofthe traditional constellations in the sameatlas. He left the reader to choose betweenthe Judeo-Christian maps and the traditionalones. The experiment had a decisive conclu-sion: no books or maps of religious constella-tions were produced after Cellarius.

By the beginning of the twentieth centu-ry, our constellations were fairly well estab-lished in the minds of observers. In 1922 thefirst General Assembly of the IAU officiallyadopted the list of 88 constellations. Belgianastronomer Eugene Delporte (1882-1955)drew up a definitive list of constellationboundaries on behalf of the IAU. Since therehad been no consensus for boundaries beforethis time, Delporte’s book D e l i m i t a t i o nScientifique des Constellations, published in1930, formulated a rigid professional system,a system in which no further substitutionsor additions could be made. Every positionon the celestial sphere is within one of the 88constellations as presented by Delporte.Actually, in Delporte’s work, there are 89defined areas, since the constellation Serpensappears in two separate parts of the sky. Thetwo parts of the constellation Serpens, nowaccepted as a single figure, are Serpens Cauda(the serpent’s head) and Serpens Caput (theserpent’s tail.) Considering this detail, peoplespoke of 89 official constellations duringmuch of the twentieth century.

In 1930, when the constellations werecaged in this definitive manner, Ophiuchus(between Scorpius and Sagittarius) became ade facto thirteenth Zodiac constellation, orperhaps better described, a thirteenth eclip-tic constellation. Ophiuchus was never part

of the classical Zodiac. In 1959,authors of the Larousse Encyclo -pedia of Astronomy , declaredthere were 89 constellationsdivided into three zones: 13ecliptic constellations, 29 con-stellations (along with the rest ofOphiuchus) between the eclipticzone and the north celestialpole, and 47 constellation sbetween the ecliptic zone andthe south celestial pole.

To point out a constellationin the planetarium, many of usslide the arrow or laser pointerover stars to make a figure, or weindicate that lines of stars repre-sent edges of a constellation.However, in the interest of accu-racy it is advisable to let adultaudiences know that most con-stellations have official bound-aries where there is only emptyspace to the unaided eye.

Some object names are deriv-ed from constellation names,such as stars (discussed below)and clouds found within con-stellation boundaries. “Sco-Cen,”for example, is an OB associationof stars known for having manysupernovae, with boundarieswithin both constellation sScorpius and Centaurus.

The StarsThe First Dictionary of Nomenclature of

Celestial Objects, published in 1983, describesover one thousand different star naming sys-tems currently in use, mostly for faintobjects studied by professional astronomers.Some of these were sanctioned specificallyby the IAU, while others derive approval fortheir professional use from astronomical tra-dition. (“Sold stars” are not one of these pro-fessionally-recognized systems!)Proper Names

The historical development of individualstar names used today goes back to Greektimes. The works of Hesiod include Arcturusand Spica in the eighth century BC. In 275 BCAratus included six individual stars inP h a e n o m e n a : Arcturus, Capella (which hecalled Aix), Sirius, Procyon (which was anentire constellation), Spica (which he calledStachus), and Vindemiatrix (which he calledProtrygeter). Archaeoastronomer Ian Rid-path points out that although Aratus’ inclu-sion of Vindemiatrix may surprise us due toits relative faintness, apparently the ancientGreeks used it as a calendar star which mark-ed the start of the grape harvest.

In his S y n t a x i s (later, A l m a g e s t) of about150 AD, Ptolemy summarized knowledge of1028 stars, including estimates of theirbrightn ess based on observations byHipparchus three centuries earlier. Ptolemydid not identify most of these stars by Greekletters as we do today. Instead he used longGreek phrases, most describing the positionof the stars within constellations. Ptolemyadded only four new names to the onesgiven by Aratus: Altair (which he calledAetus, meaning “eagle”) Antares, Regulus(which he called Basiliscus), and Vega (whichhe called Lyra, the same name as the constel-lation).

Al-Sufi, as he copied and modified theAlmagest constellations, sometimes madedirect translations from Greek to Arabicnames, such as Fomalhaut, which means“the mouth of the southern fish.” However,Al-Sufi also applied old Arabic names tomany stars in his reissued Arabic star charts,names which frequently depicted animals orpeople.

Most proper star names are a legacy fromIslamic astronomers of the Middle Ages, theoldest system of naming stars still in usetoday. When the books prepared by Arabscholars were introduced into ChristianEuropean countries, they were translatedinto Latin. The stars kept their Arabic names.The Arabic astrolabe, an instrument whosename means “star taker” and which has craft-ed points representing specific stars, furtherhelped to spread the use of the Arabic starnames to Western culture..

See Richard Hinckley Allen’s book S t a r


Northern Constellation Delporte Constellationgrid. In 1930 the Belgian astronomer EugeneDelporte (1882-1955) was commissioned by theInternational Astronomical Union to createboundaries for all the constellations. Delportewas instructed to follow, as well as possible, thedivisions which appeared in the principal atlasesthen in use. The boundaries between constella-tions were defined by arcs of hour circles and par-allels of declination for a specific reference date,the equinox of 1875. A simple adjustment for pre-cession would then give the right ascension anddeclination of any star on any date. This mapshows the northern celestial hemisphere. Credit:Eugene Delporte, Delimitations scientifiques desconstellations, Cambridge University Press, 1930.

Names, first published in 1899 and later byDover Publications in 1963, for a wealth ofinformation about the proper names of starsthat can be of interest to planetarium audi-ences. Although Star Names is a very usefulbook, E. C. Krupp cautions us that researchsince 1899 shows that some of the informa-tion in Star Names is false, including thedescription of the origin of Hercules’ 12Labors.

Also see the widely-referenced translationby Paul Kunitzsch and Tim Smart, S h o r tGuide to Modern Star Names and Their Deriva -tions (1986). The star name Betelgeuse (inOrion) offers an interesting example of atranslation problem. Kunitzsch and Smarttranslate Betelgeuse as “hand of the centralone.” But in some other books and articleswe find “the star of the right shoulder,” “thebright red star in the r i g h t shoulder,” and“the right armpit of the giant,” all incorrectlyincluding “right” as part of the meaning ofBetelgeuse. It is helpful to be aware of incor-rect translations in sources we use for plane-tarium programs and teaching.Some Proper Names Used by NASA

Three stars received unofficial alternativenames that were used in prestigious places.The names started as a conspiratorial jokeinvolving people in two planetariums. E.C.Krupp, who wears the hat of Director of theGriffith Observatory as well as Archaeo-astronomer, explains what happened:Astronaut Virgil Grissom made arrange-ments with Tony Jenzano (?-1997), Plane-tarium Manager at the Morehead Plan-etarium, to quietly rename three stars withina list that would be used in navigatingApollo spacecraft to and from the moon.Grissom submitted a list of 37 stars they wereto learn to instructors at Morehead. The cre-ated names embedded in the list are back-wards-spelled parts of astronaut names.Regor came from Roger Chaffee (1935-1967),renaming Gamma Velorum; Dnoces camefrom Edward White II (1930-1967) for Talithaor Iota Ursae Majoris (the northern star ofthe “third leap of the gazelle”); and Navicame from Virgil Ivan Grissom (1926-1967)for Segin, the center star of the “W” asterismin Cassiopeia.

Grissom, Chaffee, and White all died inthe Apollo 1 fire during a simulated count-down on January 27, 1967,

The list containing the bogus names waspassed along from the astronauts to ClarenceCleminshaw at the Griffith Observatoryplanetarium, where training in celestial navi-gation and star identification continued.Cleminshaw accepted the list; he did notquestion the authority of astronauts. When asecond Apollo crew trained at the GriffithObservatory planetarium, the three starnames remained in use. Subsequently George

Lovi used the names in his monthly Sky andT e l e s c o p e star maps and articles. By 1977,Cleminshaw knew how the names originat-ed, and he explained their origin in his bookThe Beginner’s Guide to the Constellations. SeeKrupp’s October, 1994, “Rambling Throughthe Skies” and Fred Schaaf’s April, 2003, “StarNames New and Old,” both in Sky & Tele -scope, for more details. Also note the sectionbelow “Mars: A Few Details” for the way theApollo 1 astronauts have been honored withofficial celestial names.Bayer Designations

A second star-naming system was intro-duced by German astronomer Johann Bayer(1572-1625) in his 1603 atlas U r a n o m e t r i a.“Bayer designation” is a name applied to thissystem. Bayer used 60 beautifully-drawnconstellations to identify stars, and he desig-nated each star with a Greek letter. OftenBayer designated stars in their order of itsapparent brightness within a constellationtogether with the genitive case of the Latinconstellation name.

However, frequently Bayer used a combi-nation of brightness and positional orderwithin a constellation. For example, in Leo,the brightest star (Regulus) was Alpha Leonis,the next brightest, Beta Leonis, etc. But inGemini the brightest star (Pollux) was BetaGeminorum, and the next brightest star(Castor) was Alpha Geminorum. In UrsaMajor, Bayer used Greek letters for the BigDipper stars in the order of the Dipper pat-tern. Amateur astronomers and some plane-tarians now beginning their study of starnames think of the Bayer “brightness rule” asfixed, but as James Kaler notes, “It is massive-ly violated.”

When Bayer ran out of the 24 letters of theGreek alphabet, he used Roman lower- caseletters and then upper case letters, A to Q.Although the Roman letters no longer areused for the Northern Hemisphere, theGreek letter system has been applied to theentire sky. Alan MacRobert notes that yearsago names like Alpha Centauri, meaning“Alpha of Centaurus,” seemed very naturalto people who were familiar with Greek andLatin required courses in high schools anduniversities in the United States. Todaymany people in the US who hear Bayer des-ignations are encountering Greek and Latinfor the first time. The system may seem diffi-cult or strange. Depending on general knowl-edge of Greek and Latin in a particular coun-try, as you present star names in the plane-tarium it may be helpful to discuss somedetails of the Greek alphabet and Latin geni-tive case.

Bayer modified a system that had beenintroduced in 1540, over sixty years earlier,by Italian Alessandro Piccolomini (1508-1579). Piccolomini’s catalogue designated the

brightest stars in each of 47 constellationswith sequential low-case Roman letters, forthe first time showing fairly accurate starpositions on star charts.

Since so many planetariums use pictureprojections of the constellations, it may beinteresting to know that the Western-stylepictorial star chart began with Bayer, coin-ciding with the Renaissance art revivalthroughout Europe. Bayer’s constellationpictures of scantily-clad human figures andplump women probably reflect the art val-ues of his time. The backward-facing figuresfound in Bayer’s U r a n o m e t r i a , and in lateratlases until the time of Hevelius, must be anattempt to match mirror-reversed starsfound on the outsides of opaque celestialglobes.

The first scientific use of Bayer’s atlas wasby Johannes Kepler of Germany for his 1604-1605 notation of a supernova, “Kepler’s newstar,” in the constellation Ophiuchus (record-ed in De Stella Nova, 1606). When Kepler(1571-1630) redrew Bayer’s Ophiuchus chart,he added his new “star” (labeled “N”) as wellas positions of Mars and Jupiter at two differ-ent times. Kepler reversed Ophiuchus fromBayer’s direction, facing the figure towardthe reader instead of away.Flamsteed Numbers

A third important star naming system isFlamsteed Numbers, authored by John Flam-steed (1646-1719). Flamsteed became Eng-land’s first Astronomer Royal in 1675, theyear the Greenwich Observatory was found-ed. Like Hevelius, John Flamsteed seems tohave idolized and likened himself to TychoBrahe. Flamsteed was so meticulous that henever got around to publishing his workhimself. An unauthorized and uncorrectedversion of Flamsteed’s observations between1676 and 1705, without star charts, was pub-lished in 1712 by Edmund Halley in collu-sion with Isaac Newton. Flamsteed gatheredand burned all unsold copies of the Halleypublication, but errors in the Halley publica-tion were perpetuated. A correct illustratedatlas of Flamsteed’s work, Stellarum Inerran -tium Catalogus Britannicus, often called theBritish Catalogue, was published in 1725, fouryears after Flamsteed’s death. In this so-called“equinox 1725” system, each constellation’sstars are numbered in order of their rightascension, along with the genitive case of theLatin constellation name. Therefore 80Virginis is east of 79 Virginis and west of 81Virginis. All stars were numbered, whether ornot they had a Bayer designation. So Vega is3 Lyrae as well as Alpha Lyra. The highestFlamsteed number within a constellation is140 Tauri. Flamsteed’s simple system ofArabic numbers was similar to the systemthat had been used by Islamic astronomers.

Flamsteed’s book of constellation charts,


Atlas Coelestis based on the British Catalogue,was published with modifications by Abra-ham Sharp in 1729. On the chart of Androm-eda, for example (see front cover), one seesthe Bayer system of Greek letters. An unla-beled object can be identified at the locationof M 31, the Andromeda Galaxy.

In 1930, with the publication of the IAU-supported work of Delporte, many Flam-steed catalogue star names became truly puz-zling. Some stars which previously were incertain constellations now were in differentconstellations. For example, 49 Serpentis is inHercules and 30 Monocerotis is in Hydra.

Flamsteed numbers usually were appliedonly by those in England, although JohannBode gave Flamsteed-type numbers to starsof the Southern Hemisphere. Flamsteednumbers still are used frequently, althoughthe on ly Southern Flamsteed n umbersapplied by Bode that have survived are 30Dor and 47 Tuc.Other Star-Naming Systems

As telescopes revealed fainter and fainterstars, new systems for identity were needed.The BD system, for Bonner Durchmusterung(Bonn Survey), was begun in 1859 by Germanastronomer Friedrich W. Argelander (1799-1875) at Bonn Observatory. Stars includingtenth magnitude are included in this list. Forthe BD, Argelander and subsequent mapmak-ers divided the sky into narrow declinationbands (1o) each beginning at 0 hours rightascension. Vega’s designation in this systemis BD+38o 3238, the 3,238t h star betweendeclination +38 and +39. The first BD cov-ered the north celestial pole to -2o d e c l i n a-tion, the next, called the SBD, covered thesky to -23o declination, and the last, the CDor CoD for the Cordoba Durchmusterung,extended to the south celestial pole. A totalof 1,071,800 D u r c h m u s t e r u n g star designa-tions were made. BD names still are in use,but the magnitudes given in the BD catalogsare unreliable.

A rival to the Cordoba Durchmusterungwas the nineteenth-century Cape Photo -graphic Durchmusterung (CPD), the first majorastronomical work to be carried out photo-graphically. The CPD gives the approximatepositions and magnitudes of nearly half amillion Southern Hemisphere stars.

The Henry Draper Catalog (HD), of stellarspectra is a widely used catalog. In the earlyyears of the twentieth century U.S. astrono-mer Annie Jump Cannon (1863-1941) atHarvard College Observatory listed the spec-tra of 225,300 stars in order of right ascen-sion. More were added in the Henry DraperExtension (HDE). All stars with HD or HDEdesignations have had their spectra ana-lyzed.

In 1908 another catalog was issued atHarvard: the Revised Harvard Photometry(HR), which tried to give accurate magni-

tudes for the brightest 9,110 stars (stars to afaintness of about magnitude 6.5). This listremains the basis of the now widely-usedYale Bright Star Catalogue.

The Smithsonian Astrophysical Observatory(SAO) Star Catalog, a compilation publishedin 1966, lists very accurate positions for258,997 stars, to a faintness of about 9th mag-nitude. SAO stars are numbered by rightascension within 10 degree-wide declinationstrips. The SAO Star Catalog expanded on thesingle General Catalogue of 33,342 Stars ( G C )by Benjamin Boss, published in 1937.

The United States Naval Observatory hasthe current most dominant catalog, whichcontains over half a billion stars. The USNOCatalog (A1.0 on 10 CDs) and A2.0 on 11 CDs)is the current record holder for the world’slargest star catalog. It covers the entire sky,and it was created by scanning red and blueplates from different surveys. In its prepara-tion, objects that appeared on only one col-ored plate were eliminated, which helped toevade the problem of spurious objects.

The Hubble Space Telescope Guide StarCatalog (GSC) contains 18,819,291 objects,available on two CD-ROMs. The GSC’sbrightest objects are 9t h magnitude, sincebrighter stars cannot be used by Hubble’sguide cameras. Most of the objects are 13t h-1 4t h magnitude stars, although some 15t h

magnitude objects are included and 3.6 mil-lion of the objects are faint galaxies.

A set of catalogues based on the HipparcosSpace Astrometry Mission are the H i p p a r c o sC a t a l o g (HIP), the Hipparcos Input Catalog(HIC), and the Tycho Catalog (T). The Hippar-cos spacecraft name is derived from HIghPrecision PARallax COllecting Satellite, aname honoring the early Greek astronomerHipparchus. Large scientific teams collabo-rated with the European Space Agency (ESA)to release these catalogs in 1997. HIP includesposition measurements, magnitudes, propermotions, and uncertainties . Objects areordered by right ascension. HIC gives thedata input to Hipparcos. The Tycho Catalog((now, called T y c h o - 1) is a specialized set ofHipparcos data. A user-friendly website con-tains parts of the catalogs, and it supportsthose who have and use t he catalogs:h t t p : / / a s t r o . e s t e c . e s a . n l / H i p p a r c o s / h i p p a r-cos.html. Because, unlike earlier databasestudies, Hipparcos did not operate for severaldecades, T y c h o - 1 proper motion data is rela-tively poor. Positions based on T y c h o - 1 d a t aare excellent for times near 1991 (the mid-point of the satellite observations) and areslowly getting worse as time passes

The Astrographic Catalog (AC) c o n t a i n sdata for about 4 million stars, prepared fromplates imaged about a century ago. The A Ccontains four times as many stars as Tycho-1.The Unit ed States Naval Observatory(USNO) derived improved positions by com-

b i n i n g AC data with Tycho-1 positions in ahybrid ACT Catalog. The ACT Catalog l i s t sstar positions that are almost as precise in2004 as they were in 1991. However, theTycho-2 Catalogue, prepared in 2000 by syn-thesizing data from the AC, Tycho-1, and sev-eral other catalogs, plus employing bettercomputer processing techniques not avail-able earlier, essentially has made Tycho-1 andthe ACT catalogues obsolete.

The Two-Micron All Sky Survey (2MASS)part of NASA’s Origins program recordeddata for over 470 million point sources andover 1.5 million extended sources from 1997to 2001. Although the 2MASS catalog sourcesare much less utilized than the United StatesNaval Observatory sources, PrincipalInvestigator Michael Skrutskie enthuses thatthis data volume is “several hundred timeslarger than that contained in the humangenome. Astronomers will become cosmicgeneticists, searching out patterns in thesesky maps to decode the structure and originof the Milky Way and the surrounding near-by Universe.”

There are eight types of 2MASS catalogs,including the All-Sky Point Source Catalog(“2MASS) and the All-Sky Extended SourceCatalog (“2MASX”). Object nomenclatureuses these catalog acronyms with numbersrepresenting very precise right ascension anddeclination.

Some other important professional nam-ing systems are found in the following cata-logs: the Positions and Proper Motions Catalog(PPM), and the Zodiacal Catalog (ZC) byRobertson.

Astronomers maintain web-based databases of sky objects. The largest and mostused astronomical data base, containing starsas well as other Galactic objects outside ofthe solar system (and extragalactic objectssince 1983), is SIMBAD, or “Set of Identifi-cations, Measurements, and Bibliography forAstronomical Data.” SIMBAD contains 1.54million objects with 4.4 million identifyingnames, cross-indexed to over 2200 cata-logues, based on 2.5 million bibliographicalreferences.

The CDS Service that maintains SIMBADat Strasbourg University and Harvard Uni-versity peruses over 90 journals for Galacticobjects. Astronomers at recognized institu-tions in the United States, Europe, and Japancan obtain free passwords to get internetaccess to SIMBAD. Applications for a pass-word may be sent by E-mail to CDS Servicelocated at the Strasbourg, France Astro-nomical Data Center: [email protected]. A User’s Guide for SIMBAD may beretrieved from: ftp://cdsarc.u-strasbg.fr/pub/simbad/guide13.ps.gz.

SIMBAD is just one the CDS acronymstaken from stories of The Thousand and OneNights. The stories were written in the gold-


en age of Islamic astronomy. The son (Al-Ma’mun) of the sultan (Haran Al-Rashid) ofthe Thousand Nights stories commissionedtranslation of Ptolemy’s work into Arabicand also founded observatories in Baghdadand Damascus. CDS’s ALADIN is an interac-tive digital computer atlas. The VizieR is asearch program for a large catalog library.And the Astronomer’s Bazaar allows access toover one thousand astronomy catalogueson-line.

As a result of so many naming systemsand catalogues, a bright or interesting starmay have quite a few names. The multiplenames are found on astronomy software pro-grams. For example, in the Voyager II IDynamic Sky Simulator program (CarinaSoftware), clicking on a mapped star causesat least 8 different star names pop up. ForBetelgeuse one reads: AlphaOri, 58 Ori, HR2061, SAO 113271, HD 39801, BD M+7 1005,and Hipp 27989.

The idea of one st ar (and other skyobjects) having different names may seemodd to both students and adults in our plane-tarium audiences. Brian Marsden says, “Theexistence of multiple names is very impor-tant from the point of view that it providesredundancy, thereby making it clear that, bysupplying more than one designation as acheck, we know which object we are talkingabout.”

The existence of multiple names is a factof astronomy life, and we have a responsibil-ity to explain the situation to those whoattend our star programs. An understandingof multiple names can help people whomake use of astronomy software programslike Voyager and on-line astronomy sources.Double and Multiple Stars

Since so many stars are doubles or multi-ples, a system for naming the components isnecessary. In a naked-eye binary, two starsclose together, whether a physical binary ornot, the western one is labeled 1. For exam-ple, Zubenelgenubi, Alpha Librae, is a widedouble star . The western star is namedAlpha-1 Librae and the eastern star is namedAlpha-2 Librae, even though Alpha-2 Libraeis much brighter than Alpha-1 Librae.

For stars in a telescopic binary or multiplesystem, the brighter or the first-discoveredstar (they usually go together) is called A, andthe fainter, B (and then D, E, etc.) The Romanletters follow a Bayer, Flamsteed, or catalogdesignation. Thus the white dwarf compan-ion of Sirius is named correctly with all ofthe following: Sirius B, Alpha Canis Majoris B,and HD 48915B. Perhaps one of the most dif-ficult areas of astronomical nomenclature tounderstand, astronomers in different disci-plines or specialties involving study of bina-ry stars have different ways of referring tothem. Stars expert James Kaler explains that

the term “primary” means different things inthe different disciplines. Variable Stars

In 1862 Friedrich Argelander began the BDsystem for variable stars that is in use today.Since capital Roman letter Bayer designa-tions go only as far as Q in the alphabet forfaint stars, Argelander proposed using the let-ters R to Z for naming the variable stars ineach constellation. When some constella-tions were found to contain more than ninevariable stars, the n aming system wasexpanded to two-letter designations, andthen to numbers. Now the designation con-sists of one or two letters and the genitivecase of the constellation or a “V” with anumber and the genitive (or its abbrevia-tion) of the constellation name. U Sagittarii,RR Lyrae, and V1500 Cygni all are variablestars.

The first variable found in a constellationreceives the letter R, the next S, and so on upto Z. The tenth variable is RR, then RS up toRZ. The nineteenth is SS, the ST, up to SZ.The pattern continues to YY, YZ, and ZZ andthen AA, AB to AZ, BB to BZ up to QQ to QZ.The letter J is omitted to avoid confusionwith the letter I. Thus there are 334 possibledesignations for each constellation with thisscheme, and beyond that the V with a num-ber is used. If a star with a Bayer designation

is found to be a variable, it is not given a newname, so Beta Persei (Algol), and OmicronCeti (Mira) do not have letters or V numbers.Variable stars are classified in groups namedfor one typical representative, such as “Mirastars or “RR Lyrae stars.” “Cepheid” is thename usually applied to stars like DeltaCephei. Sagittarius has the largest number ofvariable stars, with a star recently getting thedesignation of V4333 Sgr.

Extrasolar PlanetsWith well over 100 extrasolar planets now

known, some might think that the IAUwould by now have invented a proper-names system for these planets. GeoffreyMarcy, who has participated in the discov-ery of a majority of the extrasolar planets,would like to see a system which bestowsnames on the extrasolar planets “represent-ing the elusive but crucial element of humansocial coexistence on Earth. These would bewords, in different languages, for peace, fruit-ful coexistence, compromise, empathy, andpersonal and global insight. The new planetsshould belong to everyone — to all nationsand cultures.”

James Kaler says that it is beneficial tokeep the system simple because even nowthere are too many of these objects for all tohave proper names. And certainly more ofthese objects will be found.

Alan Boss, who heads the IAU section toname such planets, explains that at this timethere is no agreement for proper namesamong those astronomers working in theextrasolar planets field. The star (primary) ofa system now gets the letter A after the starname and its planets get b, c, d, etc. The starswith extrasolar planets sometimes havetongue-twisting designations that must bementioned over and over again in discus-sions and papers. One host star which has aHenry Draper classification is HD114762.William Cochran of the University of Texasfound this unwieldy enough that he namedthe host “George.” And Alfred Vidal Madjarof France refers to the host star HD209445Aas “Osiris”.

Hélène Dickel, Past Chair of the IAUWorking Group on Designations, points outthat extrasolar planet identification andstudy is still a very young field. Astronomersare too busy discovering new planets tospend much time on their names. A systemalready exists for naming multiple objects,found in the Washington Multiplicity Catalog(http://ad.usno.navy.mil/wds/new wds.html). Among many new multiple objectsthat most surely will be discovered with thenext series of space telescopes, probablythere will be a lot of extrasolar planets.Dickel thinks it likely that astronomers willdesignate these extrasolar planets, alongwith the other binary and multiple objects,


Betelgeuse. Betelgeuse, also AlphaOrionis in Bayer designation, isshown here as photographed by theHubble Space Telescope. Any timefrom next year to hundreds of thou-sands of years from now Betelgeuseis expected to become a supernovaand then a neutron star or blackhole. Betelgeuse is a semiregular vari-able star, changing from between+0.2 to 1.2 magnitude. Betelgeuse’svariability was first noticed by JohnHerschel in 1836. The name Betel-geuse is translated authoritativelyfrom Arabic as “hand of the centralone,” with no reference to the giant’sright side. Although Betelgeuse usu-ally is pronounced “Beteljuz” or“Beetle-joos,” Harvard astronomerDonald H. Menzel (1901-1976) toldfriends that he liked to say“Betelgerz” … for euphony.” Credit: A.Dupree (CfA), R. Gilliland (STScI),NASA

with the namin g system found in theWashington Multiplicity Catalog.

Novae and SupernovaeA newly-discovered nova is named with

the year in which it occurs written after thegenitive case of the constellation. Later thenova receives a variable star designation. SoNova Cygni 1975 is also V1500 Cygni.

If there is more than one nova per year ina given constellation, the novae initially aredistinguished as No. 1, No. 2, etc. This systemalso is applied to novae in the large Magel-lanic Cloud (LMC) and Small MagellanicCloud (SMC), but not to other galaxies.

In other galaxies novae and other vari-ables receive only “V” numbers.

A supernova is named with the year itoccurs and a capital Roman letter for itsorder in a list of supernovae recorded withinthat year. If the star had one or more catalogdesignations before it reached supernovastage, the catalog names are retained andnow said to apply to the “precursor” stars.For example, supernova 1987A (SN 1987A)was identified with the precursor star namedSanduleak -69o 202. The precursor was the202nd object within the 69th degree south ofthe celestial equator in The Deep Prism Surveyof the Large Magellanic Cloud, published atCleveland, Ohio’s Warner and Swasey Obser-

vatory by Nicholas Sanduleak (1933–1990).SN 1987A was the first supernova of 1987. Ifall 26 of the capital Roman letters have beenused for supernovae before reaching the endof a particular year, then double lower caseletters are applied. SN 2005aa would be thename of the 27t h supernova of 2005. Namesare applied in a sequence of aa through az,then ba through bz, and so on. The nominalreason for switching to lower-case doubleletters was that it allowed designations tosort correctly by computer. In reality, saysBrian Marsden, there is a historical reason:lower-case single letters used to be used forcomet designations (which changed in 1994),while upper-case double letters are used forprovisional names of minor planets (aster-oids) and TNOs or KBOs, both or which arediscussed later in this article. Since there areonly about three supernovae in a givengalaxy in a thousand years, this naming sys-tem’s number of possibilities is sufficient forsupernovae that are seen in all galaxies.

The very energetic objects called gammaray bursts (GRBs) have been matched conclu-sively with supernova explosions if they lastfrom 2 seconds to several minutes (longduration). Normally a gamma ray burst getsthe name of GRB followed by numbers ofyear, month, and day of discovery, such asGRB 021211, named for the GRB found onDecember 11, 2002. If more than one gammaray burst is discovered on the same day, acapital Roman letter of A, B, etc. is added tothe designation. The reason for using thedate instead of right ascension and declina-tion is that frequently GRBs have very poor-ly established initial coordinates. Most of thetime the positions of pulsars (neutron starswhich are one kind of supernova remnant)are well known. Therefore a naming systemincluding right ascension and declination isused. See http://cdswebiu-strasbf.fr/cgi-bin/Dic.

Strictly speaking, category designationsare not names. However, it is useful to knowthat supernovae are classified into two maincategories, I and II, with Ia and normal-typeII being the most common. Frequently thesupernova category is given with the discov-ery or research information. Type Ia (SN Ia)supernovae have been observed in all typesof galaxies, while types II (SN II), Ib (SN Ib),and IIc (SN IIc) have been observed only inspirals, barred spirals and irregular galaxies.The type of star which becomes a SN Ia isthought to detonate (supersonic burningfront) or deflagrate (subsonic burning front)an accreting white dwarf in a binary system.The star becoming a normal SN II is thoughtto be caused by core collapse of a very mas-sive star. Spectra and light curves are used todistinguish supernovae types. Supernova1987A was a II pec (II peculiar) core-collapsesupernova.

Type Ia supernovae have a very impor-tant role as standard candles in determiningdistances to remote galaxies. Within the pastfive years, observations of Type Ia super-novae have shown that the Hubble constantis not really constant, that its value increasesat very large distances. Along with additionaldata, the upward turning curve of recession-al velocity of distant galaxies containingType Ia supernovae has pushed astronomersto invoke the exotic concept of abundantdark energy. Topics of dark energy and typeIa supernovae go together in a planetariumprogram about cosmology.

Coordinate System Epoch andTime are Important

Early star charts had no coordinate axes.Bayer introduced grid lines in his 1603 Urano -m e t r i a, so that each star could be distin-guished to within a few tenths of a degree.Flamsteed’s posthumous British Cataloguecontained two innovations that have beeninvaluable to astronomers: right ascensionand declination of stars and an adjustmentfor precession.

To communicate positions of very faintobjects seen with today’s powerful telescopesrequires very precise coordinates. Astrono-mers study objects at many different wave-lengths, so they need a precise system formatching observations.

Precession movement, the slow westwardmigration of the vernal equinox positionalong the Zodiac, is a very important consid-eration in fixing accurate coordinates. Hip-parchus of Nicaea and Rhodes (190 BC-120BC) made a highly accurate calculation ofthe rate of precession, 46” per year. That isvery close to the modern value of 50.26” peryear, and it is much better than the value of36” per year found by Ptolemy nearly 300years later. A number of studies indicate thatprobably precession was noticed earlier byancient Egyptians. Hipparchus may haveemployed Babylonian data to find thelength of the tropical year (time betweensuccessive arrivals of the sun at the vernalequinox), checking it against data he gath-ered himself as well as data of earlier Greekscientists. Applying his determined value ofthe tropical year, Hipparchus deduced theprecessional rate.

As precession constantly changes the posi-tion of a star or other object with respect tothe vernal equinox or any reference position,the exact time or e p o c h on which the rightascension and declination (or other coordi-nates) are based must be identified. For anydate the coordinates can be adjusted to astandard date, the epoch. The most commonstandard date for coordinates given in thetwentieth century was 1950.0 and the inter-val of time from that epoch was based on thesun reaching longitude 285o. This is the


Tycho Supernova Remnant (TychoSNR) in X-Ray. Here we “see” in X-rayradiation the nebula of a shockwavegenerated as the material from thesupernova expands into the sur-rounding gas and dus t. In 1572Danish astronomer Tycho Brahe sawthe next-to-last-observed supernovain the Milky Way and was so im-pressed that he devoted much of theremainder of his life to astronomy.Using IAU nomenclature for super-novae, this object is SNR 1572, since noother supernovae were noted in 1572.A SIMBAD “Query Result” shows thatSNR 1572 has a large total of 42 differ-ent identifiers, mostly due to differ-ent catalog listings. A frequently-used alternative name for SNR 1572 isG 120.1+1.4, 3C 10, an entry in David A.Green’s Catalogue of Galactic Super-nova Remnants. Credit: S.L. Snowden,ROSAT, MPE, NASA.

Besselian 1950 or B1950 system of coordi-nates.

There is a difference between “Equinox”and “Epoch”. Many older star catalogues use“Epoch” to be the date from which propermotions should be applied to the tabulatedpositions, which may be different from the“Equinox” (in terms of precession) to whichthe mean positions are referred.

In 1984, as precessional mot ion hadenlarged the difference between an object’sB1950 coordinates and its coordinates basedon a current-date position of the VernalEquinox, the International AstronomicalUnion (IAU) changed both the epoch andtime standard for coordinates. The standardepoch became 2000.0, and the interval oftime for transformation from that epochwas changed to the Julian century of 36525days. This system is the J2000 system ofcoordinates.

It is important for astronomers to notewhether they are using B1950 or J2000 coor-dinates. The amount of difference can beabout 3 minutes of right ascension and aquarter of a degree of declination.

The Nine PlanetsMost planetarians are aware that the plan-

et names we use are all those of Roman gods,with many of the attributes of Greek gods.But a review, with further details, should begiven in any inclusive treatment of astro-nomical names.

Mercury is the Roman god of commerce,travel, and thieving and is the counterpart ofthe Greek messenger to the gods, Hermes.

Venus is the Roman name representingAphrodite, the Greek goddess of love andbeauty. Mars was a Roman god of agriculturebefore its association with the Greek god ofwar, Ares. Jupiter (Jove) is the patron god ofthe Roman state, counterpart to the chiefOlympian god Zeus, son of Cronos. Saturn,like Mars, was a Roman agricultural goduntil it became identified with the GreekCronos, son of Uranus and Gaia.

When Uranus was discovered by WilliamHerschel (1738-1822) on March 13, 1781, heproposed the name of “the Georgius Sidus”(George) in honor England’s King George III(1738-1820, sometimes called the “insaneking”, a condition resulting from a geneticdisease or “the king who lost America”.Others called the new planet “Herschel.” Butit was “Uranus,” the name suggested byJohann Bode (1747-1826) because Uranuswould fit with the other planet classicalnames, which eventually stuck. By about1850 all astronomers had accepted the nameUranus. We realize now that Uranus wasseen in 1690, by John Flamsteed, becauseFlamsteed recorded it on a star chart as 34Tau.

The story of Neptune’s discovery, which

twists through details of previous sightings,work by people in both Europe and GreatBritain based on theoretical calculations, andchance events that possibly robbed someastronomers (and an amateur astronomer) offame, is well worth planetarium programtime. After Neptune was discovered and itsorbit had been worked out reasonably well,old records showed that earlier astronomershad seen it. Galileo was just one of those whosaw Neptune, recording the planet at leastthree times, first on December 28, 1612, andthen on January 27 and January 28, 1613.Galileo even noted that Neptune, which hecalled a star, had moved away from anotherpoint, now known to be a real star. JosephJerome de Lalande (1732-1807) of France re-corded Neptune on May 10 and 12 in 1795.John Herschel (1792-1871) even saw it, on July14, 1830, recording it as a star. John Lamont(or Johann von Lamont, 1805-1879), who wasborn in Scotland but who lived most of hislife in Munich, recorded Neptune at leastthree times — October 25, 1845, September 7,1846, and September 11, 1846 — the last datejust 12 days before its identification as a plan-et.

The name Neptune, Roman god of the seaand counterpart to the Greek Poseidon, wasapplied to the eighth planet soon after it wasfound. Conventionally, credit for Neptune’sdiscovery is given equally to Urbain JeanJoseph Leverrier (1811-1877) of France andJohn Couch Adams (1819-1892) of GreatBritain. Both Leverrier and Adams calculatedthe probable location of a new planet, basedon the deviation of Uranus from its predict-ed orbit applying Newton’s gravitationallaw. The first sighting, based on Leverrier’spredictions, was on September 23, 1846, byJohann Gottfried Galle (1812-1910) andHeinrich Ludwig d’Arrest (1822-1875) at theBerlin Observatory. See http://www-groups. d c s . s t a n d . a c . u k / ~ h i s t o r y / H i s t T o p i c s /Neptune (1996).

As an interesting sideline to Neptune’s dis-covery, it is difficult to determine if Adamsand Leverrier deserve equal credit. Some doc-uments pertaining to Adams’ work werefound in Chile in 1999, and they have beenstudied by historian Nicholas Kollerstrom ofUniversity College London. Kollerstrombelieves that British claims have been exag-gerated. Traditionally Britain’s AstronomerRoyal George Airy (1801-1892) has been criti-cized for being slow to respond to Adams’request to look for the planet, in fact beingmentioned by biographers as the most con-troversial Astronomer Royal. Adams gaveAiry information on the position of the“new planet” on October 21, 1845 and it wasJuly 9, 1845, before Airy asked James Challis(1803-1882), Director of the CambridgeObservatory, to begin a search for it. Challis

reluctantly looked and saw the planet onboth August 4 and August 12, 1845; but thenhe did not take the necessary time to com-pare all the points seen at those times withpoints he had recorded on July 30. Challiswould have found Neptune if he had madeall of the tedious comparisons. From analysisof the Chile documents, Kollerstrom con-cludes that Challis did not have a good indi-cation of the planet’s location. The recordsshow that Adams changed his mind repeat-edly and that his predictions varied over 20degrees of sky. But better maps would surelyhave helped Challis. Brian Marsden notesthat “Galle and d’Arrest had the singularadvantage of the availability of the newBerlin chart of the appropriate region.”

Pluto (with now-questionable status as aplanet) was discovered on February 18, 1930,by Clyde W. Tombaugh (1906-1997) using ablink comparator at the Lowell Observatoryin Flagstaff, Arizona. The discovery of theninth planet was the culmination of a thirdsearch funded by Percival Lowell. Tom-baugh found Pluto (magnitude of approxi-mately 13.5) in a position calculated fromsupposed perturbations by Uranus andNeptune. Now we understand that the gravi-tational effects are far too small to makesuch perturbations. Thus Tombaugh’s dis-covery was a fortunate accident. Tom-baugh’s story of Pluto’s discovery, recordedin a number of places, is very engaging andworthy of treatment in planetarium pro-grams. On October 22, 1988, at the annualGreat Lakes Planetarium Association (GLPA)conference at Bowling Green, Ohio, Tom-baugh delivered a spell-binding presentationof “The Discovery of the Planet Pluto”. Hedistributed photographs and wrote personalautographs on them for conference partici-pants.

The name Pluto, the Roman god of theunderworld and the counterpart of theGreek god Hades, was first suggested byVenetia Burney, an eleven-year-old girl fromOxford, England. Pluto is so far from the sunthat it seems to be in the solar system’sunderworld. Appropriately, the first two ini-tials of Pluto are those of the benefactor ofsearches for it, Percival Lowell. The follow-ing names also were suggested for the ninthplanet: Atlas, Aretemis, Tantalus, Chronus,Perseus, Vulcan, and Minerva, althoughMinerva was already a minor planet.

People have speculated on the possibilityof a major “Planet X” beyond the orbit ofNeptune. (Pluto also was given the title of“Planet X” before its discovery.) WhenVoyager 2 flew near Neptune, the discrepan-cies between data showing existence ofanother planet and data showing no planetvanished. There is no planet the size of Earthor larger in the region beyond but near to


Neptune. If an Earth-sized object someday isfound far beyond Neptune, the IAU mayhave a chance to name a new planet.

Planetary NomenclatureHow Names are Approved

Generally, when images first are obtainedfor the surface of a planet or a satellite, anaming scheme is chosen. A few of the majorfeatures are given names, usually by themembers of the appropriate IAU task group.When later higher resolution images andmaps are available, features that investiga-tors want named are supplied with names.Suggestions to the task group may comefrom any source, and a file is kept of appro-priate names that may be used. Names suc-cessfully reviewed by a task group are sub-mitted to larger panel, the Working Groupfor Planetary System Nomenclature(WGPSN). After review by the WGPSN, suc-cessful names are considered as approvedprovisionally and they can be used on mapsand in publications as long as the provisionalstatus is stated clearly. The provisionalnames then are presented for adoption to theIAU General Assembly, which meets everythree years. A name is not considered to beofficial until then. Transactions of the IAUlist approved names. If you wish to make asuggestion, you can submit it to the U.S.Geological Survey, Branch of Astrogeology,Attention Jennifer Blue, Room 409, 2255 N.Gemini Drive, Flagstaff, Arizona 86001 or E-mail [email protected]. Suggestions are for-warded to the appropriate IAU task groups. Some General IAU Rules

Rules for all names adopted by the IAU fol-low certain general rules and conventions,which have been reexamined and amendedthrough the years. Planetary Nomenclaturerules are as follows:

1. The name should be simple, clear, andunambiguous.

2. The number of names chosen for eachbody should be kept to a minimum, andtheir placement governed by therequirements of the scientific commu-nity.

3. Duplication of the same name on two ormore bodies should be avoided.

4. Individual names chosen for each bodyshould be expressed in the language oforigin.

5. Where possible, themes established inearly solar system nomenclature shouldbe used and expanded upon.

6. Solar system nomenclature should beinternational in its choice of names.Recommendations submitted to theIAU national committees will be consid-ered, but final selection of the names isthe responsibility of the IAU. TheWGPSN strongly supports equitableselection of names from different ethnic

groups/countries; however, a higherpercentage of names from the countryplanning a landing is allowed on land-ing site maps.

7. No names having political, military, orreligious significance may be used,except for names of political figuresprior to the 19th century.

8. Commemoration of persons on plane-tary bodies should not be a goal in itselfbut should be reserved for persons ofhigh and enduring international stand-ing. Persons being so honored musthave been deceased for at least threeyears.

9. When more than one spelling a name isextant, the spelling preferred by the per-son, or used in an authoritative refer-ence, should be used. Diacritical marksare a necessary part of a name and willbe used.

10. Ring and ring-gap nomenclature andnames for newly discovered satellitesare developed in joint deliberationbetween WGPSN and IAU Commission20. Names will not be assigned to satel-lites until their orbital elements are rea-sonably well known or definite featureshave been identified on them.

Naming ConventionsIn addition to the above rules, the WGPSN

and its task committees of the IAU followthese naming conventions

1. Names for all planetary features (usuallyin Latin) include a descriptor term, withthe exception of two types. The first ex-ception is craters and the second excep-tion is some features on Io (Jupiter satel-lite) and Triton (Neptune satellite),because they are recognized as beingtransitory.

2. The naming convention for a featuretype does not normally depend on size.Exceptions to this rule are channels(v a l l e s ) on Mars and craters on theMoon, Mars, and Venus. Naming con-ventions for craters and channels dodepend on size. Regio was used as a clas-sification feature on early maps of theMoon and Mercury, drawn from tele-scope observations, to describe vaguealbedo features. R e g i o now is used todelineate a broad geographic region.

3. Named features on bodies so small thatcoordinates have not yet been deter-mined are identified on drawings of thebody that are included in the IAUTransactions volume of the year whenthe names were adopted. Satellite ringsand gaps are named for scientists whohave studied these features. A system forplanetary atmospheric features at pre-sent is informal. A formal system will bechosen in the future.

4. Boundaries of many large features (t e r -rae, regiones, planitiae, and plana) are nottopographically or geomorphically dis-tinct. The coordinates of these featuresare identified from an arbitrarily chosencenter point. Boundaries and subse-quent coordinates may be determinedmore accurately in the future from geo-chemical and geophysical data.

Organization of the Planetary NomenclatureGazetteer

A system of naming planet surface fea-tures is needed so that a particular feature onthe surface of a planet or a satellite can belocated, described, and discussed.

One can obtain detailed informationabout all names of topographic and albedofeatures of planets and satellites, as well assome planetary ring and ring-gap systemsbeginning at http://planetarynames.wr.usgs.gov. The document is under continuousdevelopment. The edition of the Gazetteer ofPlanetary Nomenclature described at thisweb address at the time this article was pre-pared con tains all bodies named andapproved by the IAU from 1919 through1997. The appendices available at this addressare very informative.

Forty-seven descriptor terms or featuretypes are listed in the Planetary Nomencla-ture Gazetteer. Appendix 4 gives 172 specificsources of planetary names. Appendix 5 con-tains definitions of all Latin-named featuretypes with their plurals: astrum, catena, cavus,chaos, chasma, colles, corona, crater, dorsum,eruptive center, facula, farrum, flexus, fluctus,fossa, labes, labyrinthus, lacus, landing site,large ringed feature, lenticula, linea, macula,mare, mensa, mons, oceanus, palus, patera,planitiae, planum, plume, promontorium, regio,reticulum, rima, rupes, scopulus, sinus, sulcus,terra, tessera, tholus, undae, vallia, vastitas. Theterms l a c u s (small plain), o c e a n u s (large darkarea), p a l u s (small plain, promontorium(headland), and r i m a (fissure) are used onlyfor the Moon. Notice there is no c a n a l e(canali).

Appendix 6 of the Gazetteer lists the cate-gories of features by planet and satellite andthe adopted convention for naming a partic-ular feature on that planet or satellite. Forexample, craters on Mercury must be namedfor deceased artists, musicians, painters, andauthors. Rupes (scarps, denoted as rup\-es f o rthe plural) are to be named for ships of dis-covery or scientific expeditions, and v a l l e s(valleys) get the names of radio telescopefacilities.

Venus’ 22 different types of featuresreceive names for women and goddesses.V a l l e s (valleys) on Venus get either thenames of river goddesses, if they are less than400 km in length, or the name for the planetVenus in different world languages, if they


are over 400 km in length. Venus’ cratersreceive either the names of famous women,if they are over 20 km in diameter, or com-mon feminine names if they are less than 20km in diameter. Features called fossae ( l o n g ,narrow, shallow depressions) and lineae (darkor bright elongate markings) receive namesof war goddesses. This latter conventionseems strange for a planet that the Greeksheld as a goddess of love and beauty.

The one exception to the women-onlynames rule for Venus is 19th century scientistJames Clerk Maxwell of Scotland (1831-1879).Maxwell, famous for his theories of electro-magnetism which allowed the VenusMagellan mission’s radar, is honored withMaxwell Montes. Maxwell Montes is thehighest mountain on Venus, taller thanEarth’s Mount Everest.

In Appendix 7 of the Gazetteer one findsthe source of names for planets and satellites,as well as discovery dates. A total of 38 ofJupiter’s satellites and 30 of Saturn’s satellitesare found in the approved-name list. Morehave been confirmed. It is not clear that al ofthe unconfirmed satellites of Jupiter andSaturn actually are satellites. Asteroids Eros,Gaspra, Ida, and Mathilde, are listed in thissource, although many additional asteroidsnow have names (See the discussion below.)Most planet and satellite names are charac-ters found in classical mythology.

The names of the Uranian satellites comeprimarily from plays by Shakespeare (Eng-lishman William Shakespeare, 1564-1616,although the actual writer of “Shakespeare”is disputed) Interestingly, there is an Ariel inThe Tempest by Shakespeare, but there also isan Ariel in The Rape of the Lock by AlexanderPope (1688-1744). Brian Marsden thinks itlikely that William Lassell (1799-1880), whodiscovered the pair of satellites in 1851,intended Ariel and Umbriel both to repre-sent characters from Pope’s work

The c omplet e IAU file of planetarynomenclature is sorted in two ways, first,alphabetically by planetary body, satellite,and feature type; second, alphabeticallywithout respect to planet or feature type.Coordinates listed in columns labeled “lat”and “long” are taken from the maps identi-fied in columns “quad” and “map,” or fromdigital images. Coordinates of features areupdated occasionally as new observationaldata become available. For maps publishedby the United States Geological Survey(USGS), the field ‘quad” identifies the infor-mal name of the map, and the field “map”lists the USGS map identification “I” number.For identification on lunar maps publishedin the 1960s and early 1970s or Russian mapsof Venus published in 1985 and 1986, differ-ent systems of identification are used.

Continent and ethnic group are identifiedin the gazetteer by “ct” and “et.” This system

allows astronomers to balance representa-tion from different countries

The MoonAlthough the Moon currently is subject to

the naming procedures of the WGPSN foundin the Planetary Nomenclature Gazetteer,the Moon’s unique position both in our skyand in history makes it worthy of additionaldiscussion. The book Mapping and Namingthe Moon: A History of Lunar Cartography andNomenclature by Ewen A. Whitaker, is awonderful source of information.

The maria, which always are directedtoward the Earth as the moon rotates in thesame period that it revolves, have inspiredname creation throughout human history.The Chinese idea of a rabbit sitting on itshaunches pounding rice is what Whitakercalls “an excellent example of a springtimemoonrise image.” (p. 6). The perception of adragon, tree, and little man which can betraced to Albertus Magnus (c . 1 1 9 3 - 1 2 8 0 ) ,found its way into present lunar nomencla-ture, first via Shakespeare, as he wrote of “thedog, the bush, and the man,” and then toPierre Gassendi (1592-1655) of France, as heincluded Homuncio(“the little man”) in hissystem dated to about1630.

Two lunar namesmentioned by Plutarch(c. 46 AD-119 AD), whichsurvived to the first halfof the seventeenth cen-tury, are Penetralia He -cates a nd Ca spia . Plu-tarch wrote that the“greatest hollow” on themoon was called t h eShrine of Hecate. Whit-aker concludes that t h eShrine of Hecate, wheresouls passed, p r o b a b l yrefers to Mare Imbrium.The Moon’s Caspia o rCaspian Sea e v i d e n t l ywas a non-specific fea-ture that was applied toMare Crisium by theseventeenth century.Plutarch categorized thepart of the Moon turnedaway from Earth as T h eEly sia n Plain and thepart toward Earth as ThePlain of Persephone.

Leonardo da Vin ci(1452-1519) of Italy andJan van Eyck (c . 1 3 9 0 -1441) of Belgium, artist-inventors, and WilliamGilbert (1540-1603), phy-

sician to Queen Elizabeth I of England andan early investigator of magnetism, madethe only known pre-telescopic drawings ofthe moon. A book that Gilbert published in1651 contains a lunar map with a total of 13Latin names. We find B r i t t a n n i a for MareCrisium, Continens meridionalis for Mare Nu-bium, Insu la Borea lis for parts of MareFrigoris, Regio Magna Occidentalis for MareSerenitatis, and Regio Magna Orientalis f o rMare Imbrium. Gilbert, agreeing with daVinci, thought that dark areas representedland and light areas represented seas.

The first lunar map made with the aid of atelescope was drawn by Thomas Harriot ofGreat Britain (c.1560-1621), although almostno one knew of it until 1965. Harriot madehis first lunar sketch four months beforeGalileo. Mistakenly, Galileo usually is givencredit for the first telescope map of themoon. The credit probably was misplacedbecause Galileo published sketches anddescriptions in his book Sidereus Nuncius(Sidereal Message). Harriot used a system ofnumbers for lunar features that were some-what like the Bayer designations for stars.


Colorful Moon. On its way to Jupiter in 1992 the Galileospacecraft took 15 photographs of the near side of themoon with three color filters. The pictures were com-bined into this exaggerated color collage to emphasizecomposition differences. The blue colors show titanium-rich regions, while orange and purple depict areas rela-tively lacking in titanium and iron. Mare Tranquillitatis(the Sea of Tranquility) is the royal blue area on theright. Oceanus Procellarum (the Ocean of Storms) is thelarge blue and orange area on the left, the moon’s “rightcheek” from the perspective of the surface of the moon.The crater Tycho is the bright rayed object in the lowerpart of the picture. In 1651, Jesuit priest P. GiovanniRiccioli of Italy pos itioned the c raters he n amedCopernicus and Aristarchus in Oceanus Procellarum, theocean, ostensibly showing Church authorities that headhered to the belief that the Earth does not move. Butnotice two things: Copernicus is larger than Tycho andAristarchus is the most brilliant object in the Ocean.Ewen A. Whitaker suggests that Riccioli is really tryingto tell us that he thought the heliocentric theory wascorrect. Credit: Galileo Project, JPL, NASA.

Galileo and several later observers used sys-tems of letters, matching letters with descrip-tions in their books.

Although many also think that Galileogave the name m a r i a to the moon’s largedark basins, he did not. Galileo made a pointof writing that he did not believe that themoon was composed of soil and water ( i n-cluding seas, the meaning of the Latin maria).

Pierre Gassendi (1592-1655) of France firstapplied the Latin terms mare and maria t othe moon’s dark regions. Gassendi never fin-ished his map project, but his notes show thefeatures he called vallis, rupes, and m o n s,terms that are still in use.

Three lunar observers (Michael Van Lan-gren of Belgium, in 1645; Johannes Hevelius,in 1647; and P. Giovanni Riccioli of Italy, in1651) published maps with competing sys-tems of lunar nomenclature. Van Langrenused names of European royalty, philoso-phers, scientists, mathematicians, patrons,explorers, religions leaders, and 14 saints.Hevelius used classical names of countries,seas, and other features, and 16 of his featureterms are on the IAU Gazetteer list. Riccioliadopted the personal-name idea of VanLangren, accepting 63 of Van Langren’snames and adding 147 names of people bothliving and deceased who had a connectionto astronomy.

Riccioli was a Jesuit priest, obliged in 1651to publicly announce a belief that the Earthdoes not move. Riccioli therefore positionedfeatures which he named Copernicus,Rhaeticus, Moestilinus, Reinholdus, andAristarchus (a long with other featuresnamed for people who believed that theEarth moved around the sun) in the “ocean,”Oceanus Procellarum. Curiously, the craterCopernicus is larger than that of Tycho andthe crater Aristarchus is the most brilliantobject in the Ocean. As Ewen Whitaker sug-gests, it seems that Riccioli was telling poster-ity in a subtle but graphic way that hethought the Copernican system really wascorrect.

More about the development of lunarnames can be found in Whitaker’s outstand-ing book. After the publications of Van Lan-gren, Hevelius, and Riccioli, lunar nomencla-ture was well on its way to its modern form.

Named Lunar Formations by Mary Blaggand Karl Muller was published in 1935, thefirst lunar publication of the IAU Nomencla-ture Committee following the IAU’s forma-tion in 1922. The publication contained thefirst complete and official listing of lunarnomenclature. The System of Lunar Craters(SLC), quadrants I, II, III, IV was published insections by D.W.G. Arthur and othersbetween 1963 and 1966, under the directionof Gerard P. Kuiper (1905-1973). Later theywere republished as Lunar Quadrant Maps.

These catalogues were adopted by the IAU,and they are the basis of lunar nomenclaturethat was added later. The S L C maps wereinvaluable in the Apollo Lunar Program.

The NASA Catalog of Nomenclature ( 1 9 8 2 ) ,prepared following the Apollo Lunar Mis-sions, is the updated version of the S L C.Apollo Landing Sites are accepted IAU fea-tures. Jonathan McDowell has entered its in-formation into a frequently-updated onlinedatabase. See http://www.planet4589.org/astro/lunar.

Charles A. Wood, who helped prepare theS L C maps, explains what has led to someconfusion in some lunar feature designationstoday: In 1837 Johann Heinrich Madler (1794-1874) and Wilhelm Beer (1797-1850) ofGermany published the first detailed set oflunar maps using a 9.5-centimeter refractor.They resolved many new craters with posi-tions near larger craters, which already hadproper names. Madler and Beer gave the newcraters upper-case Roman letters, with “A”usually being the largest or nearest to thenamed crater, and they applied letters nearthe end of the alphabet to battered craters.The Roman letter designation system forcraters established by Madler and Beer wasperpetuated in the S L C maps. Even thoughthe Roman letter system remains official IAUnomenclature, the IAU does not keep trackof it.

Additionally, Madler and Beer gave lower-case Greek letters to positive lunar relief fea-tures such as mountains, ridges, and domes.In their publication for the IAU in 1935,Blagg and Muller tabulated the Madler-Beerletters. When the SLC maps were made thirtyyears later, each Greek-lettered feature wasexamined and either retained or eliminated,and many additional features were givennew Greek letters. Recently, when Woodtried to identify all of the lettered craters andpeaks on an SLC photograph of a relativelyuncluttered part of the moon, even thoughhe had helped to prepare the designations, hecould not do it! The specific sequence ofevents that has caused lunar designationconfusion are a) The SLC cartographers didnot publish a catalog of the Greek-letteredfeatures to accompany their map; b) The IAUaccepted the S L C maps as the authority onfeatures; but, ambiguously, c) the IAU latertotally abandoned Greek-lettered features.

Patrick Moore, well known Englishauthor of many popular astronomy booksand discoverer of Mare Orientale in the1930s, co-named Mare Orientale togetherwith H.P. Wilkins. Moore explains that MareOrientale now is a misnomer. Orientalemeans “east,” and Mare Orientale is on theeast side of the moon as seen in the sky fromEarth. But IAU policy, which names themoon and planet directions as they would

be seen from the surface of the object,switches Mare Orientale to the west side. Theawkward name persists.

In a view of the moon with its south polein the center and 0 degrees longitude at thetop, such as the mosaic composed of 1500images taken in 1994 by the Clementinespacecraft’s cameras, one moves clockwisefor east lunar longitudes and counterclock-wise for west lunar longitudes.

Seth Shostak, Public Programs Scientist atthe Search for Extraterrestrial Intelligence(SETI) Institute, located in Mountain View,California, notes that the moon was the firstastronomical object considered for possibletenants, and that Plutarch made the firstspeculations. The idea of life on the moonbecame politically unpopular later, whenmedieval religious authorities declared themoon was a perfect and unblemished sphere.When the telescope era began, the specula-tion on lunar life was revived. Science fictionstories such as Jules Verne’s From the Earth tothe Moon (1865) and H. G. Wells’ The First Menin the Moon ( 1 9 0 1 ) describe trips by Earthexplorers, including interesting names, butnot ones that officially were adopted.

Venus Mapped FirstVenus was the first solid body mapped

beyond Earth and the Moon. In 1726-1727,sixty years before William Herschel pro-duced an initial crude map of Mars, Fran-cesco Bianchini of Rome (1662-1729) mademany sketches of Venus. Bianchini pub-lished a composite Venus map in 1728 in hisbook Hesperi et Phosphori Nova Phaenomena


North Pole of Venus. Between 1990and 1994 the Magellan spacecraftused radar to penetrate Venus’ thickclouds. As if we are looking downbeneath the clouds, we here observedirectly over Venus’ North Pole. Thebright area seen below the centralNorth Pole in this photograph isMaxwell Montes, Venus’ highestmo untain. Maxwell Montes wasnamed for James Clerk Maxwell, theonly man with a namesake on Venus.All other features on Venus have fem-inine names. Credit: SSV, MIPL, Magel-lan Team, NASA.

sive Observationes circa planetam Venerix.Bianchini mistook markings for permanentsurface features, from which he incorrectlydetermined the length of Venus’ day and theorientation of its rotational axis.

Bianchini made a Venus chart in gores,which he intended to be cut out and pastedon a ball to make a globe. The gores includenames for dark patches which Bianchinithought were seas. Bianchini’s Venus geogra-phy commemorated scientific institutionsin Paris and Bologna, as well as explorers,monarchs, and astronomers. He named a“sea” for Magellan at Venus’ South Pole.Today we identify Bianchini’s “sea” patchesas clouds. Newer Venus maps were publishedin the 1800s, still giving the mistaken impres-sion that Venus markings are surface featuresvisible with optical telescopes.

Percival Lowell (1855-1916) drew a Venusmap with names he created himself. Themap appeared in Popular Astronomy i nDecember, 1896. Most of Lowell’s linear fea-tures appear to radiate from a central spotthat he named “Bilit.” Lowell thought thatthree shaded arcs he detected were moun-tains.

Lowell and his Flagstaff colleagues alsorecorded linear features on Mercury, Mars,and Jupiter’s satellite Ganymede. The lineswhich Lowell included on his Venus mapwere rejected more vehemently by astron-omers at other institutions than lines drawnon the Flagstaff maps of Mercury, Mars, andGanymede. Ironically, in comparing Lowell’s1896 drawing of Venus with a Pioneer Venusimage, we see a strong similarity. The Y-shaped pattern in clouds opening to thewest, which is even more obvious in ultravi-olet light, is what Lowell apparently saw.

Mars: A Few DetailsWit h so many new Martian details

observed recently by the Orbiter, Odyssey,and MER cameras, the IAU may feel pressureto accelerate the naming process on Mars.We can speculate on the futures of the manyNASA-named rocks that have been cut andphotographed by MER rovers Spirit andOpportunity. Will the rocks someday bepicked up and claimed for Martian museumsonce there is a human presence on the RedPlanet? Will the rocks be left in place withprotective barriers and identifying plaques?Will the rocks be ignored and disappear fromrecords when people colonize a region, asgeological features have disappeared onEarth?

In 1877 two events important to Martiannomenclature occurred when Mars came toa perihelion opposition, a distance of only 35million miles from Earth. The first was thediscovery (at the United States Naval Obser-vatory) and naming of the Martian moonsby Asaph Hall (1829-1907). Hall selected

names Phobos (Fear) andDeimos (Panic) from the atten-dants of the war god Mars,described in the fifteenth bookof Homer’s I l i a d . The nameswere suggested to Hall by HenryMadan (1838-1901), ScienceMaster of Eton in Eton, England.(Incidentally, Henry Madan wasthe great-uncle of VenetiaBurney, who proposed thename of Pluto for the ninthplanet.)

The second Mars namingevent of 1877 was the publica-tion of a map by GiovanniSchiaparelli (1835-1910) of Italy.This map was the first withc a n a l i , features criss-crossingMars. Schiaparelli did not firstgive the name of canali to thesefeatures; they were first report-ed and named in 1869 by FatherPietro Secchi (1818-1878), also ofItaly. In 1879 Secchi also firstnoted the existence of joinedcanali. Affirmed by Schiaparelli,both Secchi and Schiaparellithought the joined canali w e r ethe result of seasonal changeson Mars. They referred to their observedjoined c a n a l i as “gemination.” The c a n a l i ,which means “channels” in Italian, created asensational public image of intelligentMartian life when c a n a l e (singular) andcanali (plural) were interpreted in the Englishlanguage as canals holding water. Today per-ceptual psychologists, noting how both thehuman eye and cameras perceive astronomi-cal details, explain the mechanisms for theobserved but nonexistent surface canali witha high degree of confidence.

To map Mars as he saw it, Schiaparelli cre-ated many new names, diverging fromnames proposed by Camille Flammarion(1842-1925), who had just finished a Martianmap. Schiaparelli explained that he neededto create a new nomenclature system toshow features that had not been seen before.Among Schiaparelli’s 20 canali names, wefind Ganges, Indus, Nilosyrtis, Triton, Lethe,Nilus, Hercules Columna, and Phison.Although Schiaparelli modestly noted thathe did not ask that his system be approvedby astronomers, many of his names otherthan the canali still are used today. Two ex-ceptions are Valles Marineris and OlympusMons. Valles Marineris was known on Schia-parelli maps as Agathadaemon. Schiaparelligave the name of Nix Olympica to what isnow Olympus Mons. The complete story ofearly Martian maps and the people whomade them can be found in the book T h ePlanet Mars by William Sheehan.

Some features on Mars recently have beennamed for the three members of the Apollo Icrew who died in the fire at Kennedy SpaceCenter, Florida, on January 27, 1967.

On January 27, 2004, the Mars rover Spiritin Gusev Crater looked west to three nearbyhills, White Hill, Grissom Hill, and ChaffeeHill. The Apollo I Hills could be seen along anorth-south line, between 7.5 kilometers and14.3 kilometers from the rover.

On January 28, 2004, NASA announcedplans to name the landing site of the MarsOpportunity rover in honor of the SpaceShuttle Challenger’s final crew. The area inMeridiani Planum where Opportunity land-ed, on the opposite side of Mars from theApollo I Hills , will be called ChallengerMemorial Station.

The Gusev Crater landing site was renam-ed Columbia Memorial Station (see illustra-tion above).

Two IAU Working GroupsIn addition to the Working Group for

Planetary System Nomenclature (WGPSN),there is an IAU Committee on Small BodyNomenclature. This second committee dealswith the assignment of temporary and per-manent names of newly discovered minorplanets (asteroids) and comets, based on theinformation maintained at the IAU MinorPlanet Center. Brian Marsden is the directorof the Minor Planet Center, maintained atthe Harvard Smithsonian Center for Astro-physics.


Spirit at Columbia Memorial Station. Three daysafter the Mars Exploration Rover (MER) Spiritlanded successfully on Mars, plans were initiatedto give the name of the Columbia MemorialStation to the landing site. The Spirit carried a 15-centimeter plaque, mounted on the back of itshigh-gain antenna, honoring the astronauts whowere lost in the STS-107 mission. NASA Admini-strator Sean O’Keefe remarked, “As team membersgazed at Mars through Spirit’s eyes, the Columbiamemorial appeared in images returned to Earth, afitting tribute to their own spirit and dedica-tion.” This picture, taken on the 16th sol ofSpirit’s time on Mars (January, 2004), looks north-east over the Lander platform and deflatedairbags to hills that are about 3 kilometers away.Credit: Mars Exploration Rover Mission, JPL,NASA.

Minor Planets (Asteroids)More than 250,000 minor planets (aster-

oids) have been discovered to date, with dis-coveries greatly accelerated by the recentsuccesses of the LINEAR, NEAT, Spacewatch,and other search programs incorporatingwide-field, multiple-night, CCD coverage ofthe sky. Of these 250,000, 85,117 have ade-quate orbit determinations to qualify fornaming. Only a relatively small percent ofthose with known orbits actually have beennamed: 11,302

Each minor planet first gets a provisionalcode, then a final number once the orbit hasbeen determined, and finally (for many) aproper name that is attached to the finalnumber. Michael A’Hearn, a former chair ofthe IAU Committee on Small Body Nomen-clature (which used to be called the SmallBody Names Committee), notes that quite avariety of names have been suggested forand approved for minor planets from manydifferent sources, including children’s heroes,pop culture and classical music. The recent-ly-named Misterrogers for US television leg-end Fred Rogers is an example of inclusion ofa famous cultural name.

Rules for the proper name of a minorplanet (asteroid) are: 16 letters or less; nothingoffensive; if a military or political name,then the person must be deceased for at least100 years; no pets; no confusing spellings orpronunciations; and no names too similar topresent asteroid names. The suggested nameand a brief defense of it go to the IAU’sCommittee on Small Body Nomenclature,which must make the final approval. (Seeh t t p : / / w w w . s s . a s t r o . u m d . e d u / I A U / c s b n / m p names.shtml. If you would like to suggest a

name for an asteroid, write to: [email protected].

Minor planets that have been observedon two or more nights are given provisionaldesignations that consist of a designationwith the year of observation, the upper-casecode letter identifying the halfmonth ofobservation during that year, and a consecu-tive capital letter to show the order of dis-covery announcement during that half-month, which is sequenced through thealphabet as many times as necessary.

Further details on the provisional namingsystem for minor planets are given below inthe section “Nomenclature Chaos at theEdge of the Solar System.” Minor planets andKuiper belt objects (KBOs)/trans-Neptunianobjects (TNOs) are united into one largegroup in the provisional naming system.

Many times a newly-sighted object is fol-lowed for about a month, providing data todetermine a fairly-accurate orbit. When theorbit has been determined to a set precisionstandard, the object’s status is recognizedwith a permanent number.. For ten yearsafter it receives a permanent number, theminor planet’s discoverer has an option tosuggest a proper official name.. Anyone maysuggest a name to the discoverer within thatten years or to the committee directly in fol-lowing years, and there is no fee! (It seemsironic that a name received in this way isfree, as one considers the hefty charges ofcompanies selling stars.) A brief citation ofwhy the nominator believes the person orentity is worthy of the name is submitted tothe IAU Committee with the nomination.

The name and citation are placed on a list,and every two months the Committeereviews submissions. The committee’s 15members work mostly by E-mail, says mem-ber Donald Yeomans; and members usuallyprovide one of three standard responses:“Yes,” “no,” or “heck no.” Usually a majorityvote prevails, but three “heck no’s” will elim-inate a submission.

Following a suggestion from PlanetariumDirector John G. Radzilowicz at the BuhlPlanetarium in Pittsburgh, where Fred Rogers(1928-2003) had his long-running children’stelevision series, Marsden searched for anasteroid with the code letters FR for FredRogers. Marsden found it in an asteroid dis-covered by Eleanor Helin on March 21, 1993.So asteroid M i s t e r r o g e r s was identified withthe asteroid having the provisional name of1993 FR. And the new name became (26858)Misterrogers or Misterrogers 26858.

I am personally acquainted with the nam-ing procedure for a minor planet, as myfather Richard Emmons had one named forhim a few years ago. Eleanor Helin, in consul-tation with Marsden, suggested that a minorplanet she had discovered in 1985 be named

(5391) Emmons. This asteroid was provision-ally 1985 RE2, so it was another case, like 1993FR for Fred Rogers, of Marsden selecting itbecause of particular initials. Helin wasaware of satellite observations my father hadmade that helped to prove that the near-space environment is safe for human explo-ration and that he had “inspired many peo-ple who have become very well known [inastronomy] in their own right.” In 2000 theIAU officially named (5391) Emmons withthe citation: “Richard Emmons (b 1919),emeritus professor of physics at Ohio’s KentState University, had his interest in astrono-my sparked by an article published soonafter the discovery of 1932 HA, now (1862)Apollo. He was an early observer of artificialsatellites.” In a congratulatory letter follow-ing the IAU announcement, Helin wrote tomy father, “Enjoy your namesake from ‘hereto eternity’.”

Examining the list of minor planets withproper names, we find quite a few scientists.A sample includes: (2001) Einstein, (1691)Oort, (4987) Flamsteed, (4804) Pasteur, (4674)Pauling, (7008) Pavlov, and (12294) Avo-gadro. Isaac Asimov (1920-1992) and CarlSagan (1934-1996), important popularizers ofscience in the second half of the twentiethcentury, also have namesake asteroids, (5020)Asimov and (2709) Sagan. Musician-namedasteroids are an important subset, including(1814) Bach, (1815) Beethoven, and (1818)Brahms along with the much more recentEnglish group, the Beatles. Asteroid (4150)Starr, for example, is named for Beatle RingoStarr.

Marsden says, “I’m happy to see imagina-tive names … It doesn’t have to be serious. Ifit is somewhat entertaining, that’s great.Some of the best names are whimsical …”The citation for Ringo Starr’s asteroid statesthat he is “a Liverpudlian of lively personali-ty and deadpan humor who occasionally satin as drummer with the Beatles during theearly days in Hamburg.”

The seven members of the last crew of theSpace Shuttle Columbia (STS-107), which dis-integrated during reentry on February 1,2003, are immortalized with asteroids, allwith orbits in the region between Mars andJupiter, all also discovered by Eleanor Helin.Names honor Commander Rick Husband,pilot William McCool, Mission SpecialistsMichael Anderson, Kalpana Chawla, DavidBrown, and Laurel Clark, and Israeli payloadspecialist Ilan Ramon . NASA made theannouncement in August, 2003 and withIAU approval, also in August, 2003, the astro-naut-named asteroids were added to the offi-cial list.

The IAU also approves names for satellitesof asteroids and features on asteroids. Thefirst natural satellite of an asteroid, the aster-


Ida and Dactyl. While en route toJupiter in 1994, the Galileo spacecraftpassed close to the minor planet (243)Ida and discovered that it has a tinymoon. The members of the GalileoMission’s imaging and infrared teamsrecommended the moon name Dactylto the IAU, which was approved sixmonths later. The Dactyli were agroup of creatures in classical myth-ology, who either lived on Mount Idaor who were the children of Ida byZeus. (243) Ida is about 58 kilometerslong and 22 kilometers wide, whiletiny Dactyl is only 1.6 kilometerswide. Credit: Galileo Project, JPL,NASA.

oid (243) Ida, was found while data was ana-lyzed in March, 1994, by members of theGalileo Mission’s imaging and infraredteams. The project recommended the nameDactyl to the IAU, which was approved sixmont hs later. That n ame comes from“Dactyli,” a group of creatures in classicalmythology, who either lived on Mount Idaor were the children of Ida by Zeus.

The first IAU-approved asteroid surfacefeatures were for (951) Gaspra, visited by theGalileo spacecraft in 1991. Three regions onGaspra were named for scientists associatedwith the asteroid. Neujmin Regio was namedfor Grigoriy Neujmin (1886-1946), theUkrainian astronomer who discovered Gas-pra in 1916. Yeates Regio honors Clayne M.Yeates, Galileo Science Manager until hisdeath in 1991, and Dunne Regio recognizesJames A. Dunne, who served as GalileoScience and Mission Design Manager untillate 1992.

CometsComets are named for their discoverers (or

for the identification of periodic comets,such as Halley’s Comet). Many amateurshave gained fame by discovering one ormore comets. Until August, 1994, each newcomet was designated by the year of its dis-covery, followed by a lower case letter forthe order in which it was discovered thatyear. Comet 1983d was the fourth comet dis-covered in 1983 and was named Comet IRAS-Araki-Alcock for the Infrared AstronomySatellite (IRAS) and the two astronomers

who each observed the comet. Comet P/Shoemaker-Levy 9, whose frag-

ments bombarded Jupiter, gave us one of themain astronomical spectacles of the Twen-tieth Century. Planetarians attending theJuly, 1994, IPS Conference at Cocoa Beach,Florida, will remember televised pictures ofthe first of the fragment impacts coincidingwith the close of the conference. Co-namedfor Eugene and Carolyn Shoemaker (Eugene,1928-1997) and David Levy, and also knownas 1993e, the comet fragmented into 21known pieces when it approached Jupiter.Upper-case letters were assigned to each ofthe individual pieces, and pictures of Jupitershowed the signature of the pieces impact-ing Jupiter with successive “ black eyes.”

A detailed resolution to change the cometdesignation system to one that more closelyresembles the minor planets system wasadopted by the IAU General Assembly inAugust, 2002. Instead of the year/letter andyear/Roman numeral systems of the past(where the Roman numeral was for the orderof perihelion passage), a new comet discov-ery now receives a designation with the yearof observation, the upper-case code letteridentifying the halfmonth of observationduring that year, and a consecutive numeralto indicate the order of discovery announce-ment during that halfmonth. For examplethe third comet discovery reported duringthe second half of February 2005 would bedesignated 2005 D3. (See http://www.cfa.har-vard.edu.iau/lists/CometResolution.html.)

The particular nature of a cometaryobject may be indicated by aninitial prefix. The prefix A/should precede a comet designa-tion which has been found toreally be a minor planet since itsdiscovery (unless, as usually hap-pens in practice, the comet-minor planet is assigned a namereflecting its dual status). C/ isattached to a periodic cometdefined to have a revolution peri-od of more than 30 years or con-firmed observations at morethan one perihelion passage. P/ isgiven to a comet with a revolu-tion period of less than 30 years,X/ goes to a comet that cannothave a meaningful orbit comput-ed, and D/ is for a periodic (P/)comet that not longer exists or isjudged to have disappeared. If thecomet return is observed, the P/or C/ is preceded by a sequentialnumber of the number of certainreturns. The designation C/2005D3 would be used for the thirdcomet in the second half ofFebruary, 2005, if it had a calcu-

lated revolution period longer than 30 years.The designation P/2005 D3 would be appliedto the third comet in the second half ofFebruary, 2005, if it had a calculated revolu-tion period of less than 30 years. If a hypo-thetical comet P/2005 D3 were observed dur-ing 50 perihelion passages, it would then be50P/2005 D3.

To be considered a “discovery,” theobserver must confirm the comet sightingwith additional observations on followingnights. After confirmation, the observersends an E-mail to the Smithsonian Astro-physical Observatory. Reported comets arecompared with data lists of known objects tosee if the comet really is a new discovery.

It is acceptable for an object to be desig-nated as both a comet and a minor planet.This applies primarily to objects that havebeen given a permanent number, like the85,117 minor planets with good, multiple-opposition orbits. Brian Marsden points outthat the following objects now have dual sta-tus: (2060) Chiron (1977UB) = comet95P/Chiron; (4015) Wilson-Harrington (1979VA = comet 107P/1949 (Wilson-Harrington);and 7968) Elst-Pizarro = 133P/1996 N2 (Elst-Pizarro). The part of the name of these dual-status objects representing their provisionalminor planet status will be discussed withKBOs or TNOs within the later section“Nomenclature Chaos at the Edge of theSolar System”.

MeteoritesJeffrey Grossman, current chair of the

International Meteorite NomenclatureCommittee, summarizes the IAU system ofnames: All meteorites are named for geo-graphic features near a particular find or fallsite, commonly towns, streams, mountains,and lakes. If there are not enough features toname all the meteorites from an area, a geo-graphic name is selected and numbers areappended to form a series.

In Antarctica and in a part of the Sahara,both of which are productive sites or“strewnfields,” the numbers following thelocation name are the 2-digit expedition-year plus a 3-4 digit specimen sequence num-ber. In the rest of the Sahara, Oman, WesternUS, and Australia, the numbers do notinclude the year; only the sequence number,as in “Dhofer 321,” where Dhofer is the loca-tion, and this specimen is number 321 foundthere. In the Hammada al Hamra section ofthe Sahara, the first meteorite found on theHammada al Hamra plateau received thedesignation Hammada al Hamra 001 (HaH001) and the most recent, the one-hundred-forty-sixth, is Hammada al Hamra 146.

Ralph Harvey of Case Western Universityin Cleveland, Ohio, gathers meteorites inAntarctica. Harvey notes that a meteoritefound in Antarctica’s Allan Hills gets what


Comet NEAT and Coronal Mass Ejection. CometNEAT, officially designated C/2002 V1, was dis-covered on November 6, 2002. The discovery waspart of the Near Earth Asteroid Tracking (NEAT)program, which employs a 1.2-meter Schmidttelescope at Haleakala on Maui, Hawaii. OnFebruary 18, 2003, when this picture was takenwith the orbiting SOHO satellite, the tail ofC/2002 V1 and an enormous solar coronal massejection seemed to be synchronized. C/2002 V1was then second magnitude, bright enough tocreate an artificial horizontal streak on theimage. A disk artificially blocks the sun. Credit:SOHO Consortium, LASCO, ESA, NASA.

he terms “a convenience designation” (thatis, not an IAU-sanctioned name) of AH com-bined with its southern-summer find date.“AH 84” denotes that the meteorite wasfound in the austral summer gathering sea-son of 1984-1985. Harvey n otes that aJapanese “convenience designation” for anAntarctica meteorite is a single alphabeticcharacter (such as Y for Yamato Mountains)instead of the two or three letters used by UScollectors in Antarctica.

Famous meteorite “ALH 84001” is official-ly “Allan Hills 84001”. It was found in theAllan Hills in December, 1984, and it hap-pened to be selected as the first (001) amongthe hundreds of specimens gathered that sea-son. ALH 84001, with an original mass of 1.93kilograms, was first classified as one of theSNC meteorites (with mineral compositionsof shergotite, nakhlite, and chassigny). Morerecently this group is simply referenced as“the Martian meteorites”, because, unlike theothers in the SNC group, ALH 84001 lacksthe SNC minerals. ALH 84001 not only hasbeen identified as Martian, but its probablelocation of origin on Mars has been found aswell. Since August, 1996, ALH 84001 has beenthe focus of a hot debate over whether ornot it carries evidence of simple past Martianlife.

If two or more numbered meteorites laterare found to be paired, their names are notchanged. The groups are then referred to col-lectively by the lowest specimen number,the most widely studied piece number, orthe largest piece number.

Most of us in planetarium positions havemet a visitor who wants to know if a particu-lar rock is a meteorite. Perhaps like me, you

have seen quite a few pieces ofindustrial slag which look likemeteorites. If you are unable todifferentiate between mete-orites and “meteor wrongs,” itis best to contact an expert at auniversity near to your plane-tarium. To obtain a number foran individual meteorite,(which it needs in order to bementioned in a journal article)you are invited to contact SaraS. Russell, Dept. of Mineralogy,Natural History Museum,London, at the e-mail address:[email protected]. A schol-arly application for a meteoritename also can be found on theweb page: http://www.uark. e d u / c a m p u s - r e s o u r c e s / m e t s o c /bullform.htm.

Nomenclature Chaos atthe Edge of the SolarSystem

A few years ago the classifica-tion of Pluto as a legitimate planet cameunder attack, and the debate continues.Instead of a planet, Pluto may be a “KBO,” oras become more accepted, a “TNO.” Pluto’ssatellite Charon may also be a KBO/TNO.

In the 1950s, Gerard Kuiper predicted thata belt of objects near the plane of the eclipticexisted beyond Neptune. In 1992, the firstsuch anticipated body was found andastronomers used the term “Kuiper beltobject” (KBO).

Then it was learned that in 1943, prior toKuiper, astronomer Kenneth Edgeworth(1880-1972) had made a similar prediction. So

some astronomers began using the designa-tion “Edgeworth-Kuiper objects” (EKOs orEKBs) for objects in the belt beyond Neptune.A 1930 prediction by Frederick C. Leonard ofthe outer belt was brought to light in 2000by Brian Marsden, and the term “Leonard-Edgeworth-Kuiper belt object” (LEKB) wasthen applied. Some astronomers suggestedthat it would be advisable to discontinueusing people’s names, changing the distantobjects’ designation to “trans-Neptunianobjects (TNOs). Currently KBO and TNO areused interchangeably, although the term“trans-Neptunian object or “transneptunianobject” (TNO) is gaining acceptance. TheScientific Organizing Committee of theEuropean Southern Observatory (ESO)Workshop on “Minor Bodies in the OuterSolar System” held in Garching, Germany, in1998, specifically recommended the termTNO over the term KBO and other designa-tions. Those who propose the change fromKBO to TNO probably know that Kuiper didnot predict any object like those we actuallyobserve. Kuiper speculated that a circularring of comets beyond 50 AU and a couple ofvery large asteroids (like Ceres) beyond 38AU might exist. However, he did not foreseea multitude of small minor planets beyondNeptune. Kuiper once remarked that itwould be ‘puzzling’ if there ‘were asteroidalbodies’ beyond 30 AU.

Further complicating classifications,TNOs that have a 2:3 orbital resonance withNeptune are called “plutinos.” Still anotherdivision, “cubewanos” (a term derived fromsounding out the letters and number of TNO1992 QB1), are objects of a division of TNOthat remain in the main belt, never travelinginside Neptune’s orbit. Cubewanos are con-fined to a belt of 42-47 astronomical unitsfrom the sun, with eccentricities of less thanabout 0.15. The term “classical KBO” some-times is meant to be synonymous with“cubewanos”. Another group, “scattered diskobjects” (SDOs) have more eccentric orbits.

For naming purposes all TNOs/KBOs areconsidered minor planets. All minor planetsreceive provisional names (before gettingfinal numbers and possible proper names)that include two capital Roman letters. Thisis different from comet provisional namesthat receive only one capital Roman letter.The first discovered KBO/TNO received theprovisional name 1992 QB1. This designationshows the year, the halfmonth, and the orderof discovery in the halfmonth. For eachmonth the “second half” is defined as begin-ning at 16d 00h and 00m Universal Time(UT). The first letter, such as the Q in 1992QB1 (and also as in a comet designation suchas 2005 D3), defines the halfmonth. A firstletter of A denotes the first half of January, aB denotes the second half of January, a C


ALH84001 meteorite. This famous meteorite, offi-cially named “Allan Hills 84001,” was the first(001) meteorite found in Antarctica’s Allan Hillsduring the 1984-85 gathering season. All scientistsagree that ALH84001 came from Mars because gaspockets within it and similar meteorites have anisotope composition that is identical to that in theMartian atmosphere. But there is strong disagree-ment on whether ALH84001 contains evidence oftiny past Martian life. Credit: JSC, NASA.

Pluto and Charon. This image ofPluto and its large satellite Charonwas taken by the Hubble Space Tele-scope on February 21, 1994. Pluto wasdiscovered by Clyde Tombaugh atLowell Observatory in 1930, andCharon was discov ered by JamesChristy in 1978 at the U. S. NavalObservatory. Pluto is named for thegod of the underworld and Charon isnamed for the ferryman who crossesthe river Styx. In addition, Pluto hon-ors Percival Lowell, who fundedsearches for the planet. Charon some-times is pronounced “Sharon,” honor-ing James Christy’s wife Charlene,nick-named “Char”. Credit: NASA,ESA/ESO Space Telescope EuropeanCoordinating Facility.

denotes the first half of February, and a Ddenotes the second half of February. The let-ter J denotes the first half of May and a letterK denotes the second half of May, becausethe letter I is omitted to avoid confusionwith the letter J. (In some old publicationsthe letter J was omitted and the letter I wasretained.) The letter Q, as in 1992 QB1,denotes the second half of August. The letterY is the designation for a minor planet orTNO found in the second half of December.As with I, the letter Z is not used as a first let-ter for the TNO/minor planet designationsdesignation. The 24 letters used gives a totalof 24 halfmonths.

The second letter in the minor planet/TNO designation, such as the B in 1992 QB1,it denotes the order of discovery within thehalfmonth. The second letter system, likethe first letter, also excludes the letter I buthere includes the letter Z, so there could be25 designated objects with a given year and agiven halfmonth that receive only two let-ters.

If more than 25 minor planets and TNOsaltogether are found for a given year and agiven halfmonth, the 26th object is designat-ed QA1, the 27th object is QB1, continuing toQZ1. After that come QA2, QB2…QZ2, etc.Often many objects are found during half amonth. For example 2003 VB12 is the provi-sional name of the 302nd object found in thefirst half of November, 2003. At the MinorPlanet Center, Marsden says that in somehalfmonths they have cycled the second let-ter through the alphabet more than 300times, representing more than 7500 objects.

Over 800 TNOs have been discovered.Some of the larger TNOs have proper namessuggested by their discoverers, which theIAU rules should be creation gods. The dis-coverers of 1992 QB1 suggested “Smiley,” fordark world spies in books by author John LeCarre. If Pluto and Charon are TNOs, they arethe largest and third largest ones, respective-ly. The second largest TNO is 2004 DW.

The TNO (50000) Quaoar, discovered in2002, was given the provisional designationof 2002 LM60. Its discoverers proposed theproper name of Quaoar for a creation god ofthe Native American Tongva tribe, the origi-nal inhabitants of the Los Angeles Basin.Quaoar, the god, was said to instill order bylaying out the world on the back of sevengiants before creating the lower animals andhumans. Quaoar, the TNO, is about half thediameter of Pluto and is larger than Ceres,the largest minor planet.

A number of TNOs are about 1000 km indiameter: (20,000) Varuna, provisionally des-ignated 2000 WR106 (found in 2000, andnamed for an important pre-Vedic god inHindu mythology, the keeper of the cosmosand the keeper of cosmic order); Ixion, provi-sionally designated 2001 KX76 (found in2001 and named for the classical father ofthe Centaur tribe); and three other provi-sionally designated objects—2002 TX300,2002 UX 25, and 2002 AW197.

The recently-discovered object calledSedna, an Inuit sea goddess, lies beyond theKuiper belt. Sedna, as yet an unofficial name,is well in from the Oort Cloud, but it is toofar out to be a scattered-disk object (SDO).Following IAU minor planet rules, Sedna hasthe designation of 2003 VB12.

Oort cloud objects are more distant fromthe sun than TNOs, and they are not limitedto the plane of the ecliptic like TNOs are.

Deep Sky ObjectsDeep sky objects include star clusters, neb-

ulae, galaxies, and quasars. Deep sky objectsare those beyond the solar system which canbe st udied well only with telescopes,although some are faintly visible with theunaided eye. Many are visible in a variety ofwavelengths, and most have multiple list-ings. The website http://adc.gsfc.nasa.gov/a d c / q u i c k _ r e f / c o m m o n _ n a m e s . h t m l # t o p )lists 426 astronomical catalog sources, somedifferent volumes of the same catalog, someof stars and variable stars mentioned earlier,and some for solar system objects. However,many of the catalogs are for deep sky objects.The same deep sky object, listed in differentcatalogues, gets different names. The situa-tion of multiple names for deep sky objects islike that of multiple names for stars andother objects — it is confusing!. Fortunatelyweb-site references usually give multiplenames for a given deep sky object.

The Messier Catalog numbers with a totalof 103 objects (or 107, 109, or 110, dependingon which of the later additions one accepts)applied by Charles Messier (1730-1817) in thelate 18th century is the most popular namingsystem for deep sky objects. Finding newcomets was Messier’s astronomical passion.Messier compiled a list of fixed sky objects sothat he would not mistake them for comets.Many of the so-called Messier objects hadbeen discovered before Messier; sometimestheir earlier identification was unknown tohim. Messier’s colleague Pierre Mechain(1744-1804) found many of the Messierobjects. Messier gave Mechain proper creditfor his discoveries.

Messier’s list contains most of the brightnonstellar objects in the northern two-thirdsof the celestial sphere. Most amateur astrono-mers who become interested in viewingdeep-sky objects begin with the Messier list.A good web site for the Messier (M) objects inorder, 1-110, along with their popular names,constellation location, and other informa-tion is http://www.rclarke.org.uk/messier2.htm.

Most planetarians know that M1 is “theCrab Nebula,” M31 is “the Andromeda Gal-axy,” and M44 is the Praesepe or “the Bee-hive” (identified as a cloud by Ptolemy, butshown by Galileo’s telescope to be starsinstead of a cloud.) However, we can expand


Sedna. This is an artistic depiction ofSedna, the unofficial Inuit ocean-goddess name of an object discoveredin November, 2003, by Michael Brownof the California Institute of Tech-nology, Chad Trujillo of the GeminiObservatory in Hawaii, and DavidRabinowitz of Yale University. Fol-lowing IAU minor-planet namingrules, the object is 2003 VB12. It isthree times farther from Earth thanPluto, taking 10,500 years to revolveabout the sun. Sedna/2003 VB12 isabout three-fourths the diameter ofPluto and the second reddest objectin the solar system, second only toMars. Credit: NASA/JPL–Caltech/R.Hurt (SSC-Caltech).

PKS285-02. In this planetary nebulaphotographed by the Hubble SpaceTelescope we see H-alpha carbon(which composes all living things)created by a former red giant star,together with a central core fadingto a white dwarf. The category nameof “planetary nebula” is misleading,as the shapes of planetary nebulaealmost never resemble planets. Allplanetary nebula have official namessuch as PKS285-02, which are catalogdesignations. However the particularintricate appearance of a nebula, likea cloud formation or cave stalactitesand stalagmites, often inspires some-one to apply a “cute” name. Perhapsmembers of planetarium audienceswould enjoy thinking of a visualanalogy for PKS285-02. Credit: R.Sahai & J Trauger (JPL), WFPC2, HST,NASA.

our vocabulary of creative nicknames forthe Messier objects (unofficial names, ofcourse) by referring to the above website.The list offered here reveals that M64 inComa Berenices is “the Sleeping Beauty” or“the Blackeye” Galaxy. A wonderful photo-graphic montage of M64 appears on p. 19 ofthe May, 2004, issue of Sky & Telescope, desig-nated as “the Blackeye Galaxy.” The unusualphotograph was created by the HubbleHeritage Project using blue, green, red, andnear-infrared light.

M17 is variously the “Omega Nebula,”“Swan Nebula,” “Horseshoe Nebula, or “Lob-ster Nebula,” while M76 is the “ButterflyNebula, “Little Dumbbell Nebula,” “CorkNebula,” or “Barbell Nebula.”

John Bakkelund has a favorite list of imag-inative but unofficial names for astronomi-cal objects beyond the Messier objects, whichplanetarians might find useful, for the samereason that he lists them: “… they add colorto interesting objects that have dull cata-logue names.” In Bakkelund’s list we find

“Ghost of Jupiter,” “Coat hanger Cluster,”“Silver Coin Galaxy,” and “Inkspot,” all inter-esting descriptive names one might mentionin planetarium programs. See http://www.geocities.com/rasctb/objnames.htm. Anothersite listing a large number of common namesor “nicknames” for deep sky objects alongwith their official designations, maintainedby the Grasslands Observatory, is http://www.3towers.com/miscella.htm.

Astronomers differ in their dispositiontoward the deep-object nicknames. Astro-physicist James Kaler prefers the official des-ignations, judging that way too many “cute”names are applied. It appears that some feelcompelled to give a jazzy name to almostevery interesting new object found by theHST, the Chandra X-Ray Observatory, andother space tele-scopes. And this,says Kaler, dimin-ishes the dignityof astron omy.Astronomer John

Feldmeier notes that both professional andamateur astronomers frequently use ab-breviated or unofficial names in their day-to-day conversations about their work.Regardless, astronomers adhere to IAU namesin papers and journals.

Often newly-discovered planetary nebulaereceive official names based on their discov-erers. For example, when astronomersGeorge Jacoby and Laura Fulton found plan-etary nebulae in the Galactic halo, the nebu-lae were named JaFu1, JaFu2, etc.

The New General Catalogue of Nebulae andClusters of Stars (NGC) was published by JohnL. E. Dreyer (1852-1926) in 1888. The NGC wasthe work of the father-and-son astronomersWilliam and John Herschel, and surely Wil-liam’s sister Caroline Herschel (1750-1848),


Galactic Center. There are a total of 17 Messier objects and other telescopic objects in the region of Sagittarius and the GalacticCenter. The sky is a 30-minute exposure on Ektachrome 400 film taken from Cerro Tololo, Chile, using a Canon 50mm lens wideopen at f/1.8. North is at the top. The photograph spans an area of about 27 by 40 degrees. We see the intricate absorbing dust lanesthat block the actual galactic center and the yellow color of old stars, dimmed to brown where the s strong reddening by inter -stellar dust. Since this film has a response to the red light of H-alpha from emission nebulae, the many H II regions are clearly seen.The largest telescopes used by Messier while looking into the Galactic Center and elsewhere were 190-mm and 200-mm reflectors.But the speculum mirrors of those telescopes would have had the equivalent light gathering power of present-day 80- to 100-mmreflectors. Alan Dyer points out (Observer’s Handbook, The Royal Astronomical Society of Canada) that a modern observer shouldbe able to see all the Messier objects, in the direction of the Galactic Center and across the celestial sphere, with a dark sky andeither an 80-mm refractor or a 100-mm reflector. Credit: William C. Keel (University of Alabama, Tuscaloosa), Cerro Tololo, Chile.

who observed in the eighteenth and nine-teenth centuries. The Dreyer/Herschel NGCcontains a total of 7,840 objects that are notsingle stars. Objects are numbered in order ofright ascension based on an 1860 epoch.With subsequent publications in 1895 and1908 (the Index Catalogues, abbreviated IC),Dreyer listed 13,226 objects — almost everynon-point like telescopic object beyond thesolar system visible with a 30-centimetertelescopes from a backyard observing loca-tion having slight to moderate pollution.

Some other important catalog systems fordeep sky objects include the ESO (EuropeanSouthern Observatory), IR (Infrared Astro-nomical Satellite), Mrk (Markarian), andUGC (Uppsala General Catalog). The numberswhich follow the letter designation can indi-cate either the order in the list or the loca-tion.

The NASA/IPAC Extragalactic Database(NED) contains positions, basic data, andover 1,275,000 identifications for 767 extra-galactic objects, references to 33,000 pub-lished papers, 37,000 notes from cataloguesand other publications, 1,200,000 photomet-ric measurements, and 500,000 positionmeasurements NED has 15,500 abstracts ofarticles about extragalactic objects and is farmore complete in extra galactic objects thanis SIMBAD, although SIMBAD now also car-ries extragalactic as well as galactic data..(Since NED began in 1988, and SIMBADbegan incorporating extragalactic data in1983, one could peruse SIMBAD if interestedin extragalactic literature for the years 1983-1988.) A big advantage of NED is that it isaccessible without charge or password to allat nedwww.ipac.caltech.edu.

Another major astronomical data base forextragalactic information is the Lyon-Meudon Extragalactic Database (LEDA), cre-ated in 1983. LEDA has finding charts ofgalaxies at almost any scale. These and morespecialized data from LEDA also are free toall at www.skylab.com.au/leda.html.

The NGC/IC Project currently is trying toclear up identification problems relating toboth stars and deep sky objects. Amateurastronomers find the NGC to be a very im-portant source. But, as Steve Gottlieb notes,“A staggering 15 to 20 percent of all NGCentries have known or potential identifica-tion problems – poor positions, misidentifi-cations, duplicate entries, incorrect classifica-tions, and confusion with single or multiplestars or even Palomar Sky Survey platedefects.”

Initiated by Harold Corwin of the NASAExtragalactic Database (NED) team, a collab-orative project of piecing together the truediscovery stories and presenting correctedidentifications and modern data for theentire NGC (New General Catalogue) and IC

(Index Catalogue) is under way. One canaccess the NGC/IC Project site at www.ngcic.com to find summaries of several thousandpuzzle solutions by principal investigatorsHarold Corwin and Malcolm Thomson. Also,German amateur astronomer WolfgangSteinicke has compiled a Revised NGC/ICwith exact positions, catalog data, and tableof biographical information on the original160 contributors to the NGC and IC.

The Big BangThe simple name of “the Big Bang” for the

origin of the universe is used by all astron-omers. Fred Hoyle (1915-2001) introduced theterm in a series of popular radio talks in thein Great Britain in the late 1940s. Ironically,Hoyle probably intended the term to bederogatory, a put-down to arguments givenby George Gamow (1904-1968) for a suddenbeginning of the universe. Hoyle retaliatedwith “the Steady State Universe” theory.Proposed in 1948 by Hoyle, Hermann Bondi,and Thomas Gold, The Steady State Universehas no beginning. When cosmic microwavebackground radiation was discovered in 1965by Robert Wilson and Arno Penzias (forwhich they received the 1978 Nobel Prize inphysics), predicted by George Gamow, RalphAlpher, and Robert Herman in 1948-49, theSteady State Universe theory lost favor.

In the August, 1993, issue of Sky & Tele -scope, Timothy Ferris announced a contest torename the Big Bang. There were three con-test judges: Carl Sagan, Ferris, and HughDowns. Although over 13,000 entrees weresubmitted from 41 countries, the judgescould not find a better name. Concluded

Sagan, “Here’s nothing that even approachesthe phrase ‘Big Bang’ in felicity … The idea ofspace-time and matter expanding togetherand not ‘into’ anything may be permanentlybeyond reach in the universe of short andlucid phrases.”

Some Final ThoughtsAnd so we reach the end of a very long

look at how celestial objects are named.Naming seems to be a human need, or atleast a result of the way the human mindfunctions. Naming also heightens our per-ception of human importance in the schemeof things. Percival Lowell remarked, “Nam-ing a thing is Man’s nearest approach to cre-ating it.” Somehow our involvement makesthe thing we name more meaningful.

Early cultures kept the terrors of nightdarkness and the unknown away by givingnames t o the constellat ions. As theyattached names over time people becamemore comfortable with the universe andmore accepting of its objects. When peoplecategorize an object, the act may create afeeling of understanding, even though actualunderstanding does not exist.

Proper names resonate with particularmeanings, adding a motivational aspect tolearning astronomy. Justifying his names forMartian features, Schiaparelli said: “… grantme the chimera of these euphonic names,whose sounds awaken in the mind so manybeautiful memories.”

So there are multiple human reasons fornaming astronomical objects: 1) to make theuniverse more meaningful and interesting, 2)to communicate information about objects


WMAP. An analysis of this high-resolution map of microwave radiation from theorbiting Wilkinson Microwave Anisotropy Probe (WMAP) in 2003 shows, togetherwith other important cosmological ideas, that the universe is 13.7 billion years old(accurate to 1 percent) and that it currently is expanding at the rate of 71 kilome-ters/second/megaparsec (accurate to 5 percent). The name “Big Bang,” now almost ahousehold expression, was first used by astronomer Fred Hoyle in radio presenta-tions in Great Britain during the late 1940s. Although with WMAP astronomershave found a superior estimate of the time since the Big Bang, no one can find a bet-ter name for the start of the universe. Credit: WMAP Science Team, NASA.

in the sky and 3) to tame the cosmos so thatwe feel more comfortable within it. Thenames that we use for astronomical objectshave interesting stories that we can andshould share in planetarium programs, sto-ries that for psychological and other reasonsare likely to resonate with interests of mem-bers of our audiences.

We must be grateful to the IAU commit-tees who work very hard to establish work-able systems and approve new appropriatenames for objects, even though their effortsdo not eliminate all confusion. With anexplosion of discoveries from new telescopesand space explorations, it is hard for the offi-cial naming processes to keep up. The detailsand number of official naming conventions,unless one uses them continuously, aretedious. And multiple names continue toconfound many of us. We may hope that thepresent situation of multiple names for somany objects will someday become moreuser-friendly. In spite of these inconve-niences, consider what the condition ofastronomical nomenclature and its useswould be if the IAU committees did not reg-ulate object names … an unmanageable tan-gle of misidentifications.

To close in the vein with which this arti-cle began, Andre Heck of the StrasbourgAstronomical Observatory takes an unusualstand regarding adopting a star or anothersky object. Heck suggests that “instead of pos-ing as a shocked goddess,” at the practice offorming a personal connection with anastronomical object, astronomers shouldtake advantage of the interest which hasbeen shown by people responding to thebusinesses which “sell stars.” The astronomycommunity, says Heck, should build on pub-lic and student interest in astronomy by pro-moting the “adoption” (not the selling) ofvarious sky objects. Heck concludes that sup-plying people who “adopt” sky objects withaccurate and up-to-date information abouttheir objects, including professional data andbibliographical references, and sometimescomplete scholarly papers, combining all theinformation in a pleasing package, wouldcost little and be very educational. Heckenthuses, “I see kids and adults showingaround information on the latest advancesrelating to their adopted objects.” Heckbelieves that this mode of popularizingastronomy as well as accurate education ofan interested sector of the public could cre-ate a large source of political and economicsupport for astronomy.

Continuing his provocative discussion,Heck notes, “We should never forget that weEarth-based astronomers have no more rightto name celestial objects than hypotheticalbeings living somewhere else in space. Ourrules are no more than human-made naming

conventions, recognized by our learned bod-ies, to avoid confusion and allow immediateidentification.”

I am grateful to many people who answeredquestions as I prepared this manuscript. Particu -larly, I thank four astronomers who read themanuscript carefully and made many sugges -tions: Hélène R. Dickel, Research Professor ofAstronomy Emerita, University of Illinois andMember/Past Chair of the IAU Working Groupon Designations; James B. Kaler, Professor Emer -itus of Astronomy, University of Illinois; E. C.Krupp, Director of Griffith Observatory; andBrian G. Marsden, former Associate Director forPlanetary Sciences at the Harvard-SmithsonianCenter for Astrophysics and Director of theMinor Planets Center.

Selected ReferencesAllen, Richard Hinckley. (First published in

1899 under the title of Star-Names andTheir Meanings). Star Names: Their Lore andMeaning. New York: Dover Publications,1963.

Beatty, Cheryl and Fienberg, Richard Tresch.“The Big Bang Challenge.” Sky & Telescope,March, 1994, pp 20-22.

Bishop, Jeanne E. “Focal Point: The WrongWay to Hustle Stars.” Sky & Telescope, Feb-ruary, 1990, p. 124.

Burdick, Alan. “Name That Star.” D i s c o v e r ,February, 2000, pp. 70-74

Dobbins, Thomas A. and Sheehan, William.“The Canals of Mars Revisited.” Sky & Tele -scope, March, 2004, pp, 114-116.

Gottlieb, Steve. “Restoring Order to theNight Sky.” Sky & Telescope, N o v e m b e r ,2003, pp. 113-118.

Gingerich, Owen. The Great Copernicus Chaseand Other Adventures in Astronomical His -tory. Cambridge: Sky Publishing Corp. andCambridge University Press, 1992.

Gurshtein, Alexander. “When the ZodiacClimbed Into the Sky.” Sky & Telescope,October, 1995, pp. 28-33.

Heck, Andre. “An Alternative to SellingStars.” Sky & Telescope, March, 1997, p. 6.

International Astronomical Union. Designa-tions and Nomenclature of CelestialObjects. http://www.iau.org/IAU/Activites/nomenclature.

International Planetarium Society; ed .,Bishop, Jeanne E. “International Plane-tarium Society Sets Forth Guidelines onStar Naming.” The Planetarian, Vol. 17, No.3, September, 1988, pp. 20-21.

Kaler, James web site: http://.astro.uiuc.edu/-kaler/sow/starname.html.

Krupp, E. C. “Night Gallery: The Function,Origin, and Evolution of the Constella-tions. Archaeoastronomy: the Journal ofAstronomy in Culture, Volume XV, 2000,pp. 43-63.

Krupp, E. C. “Rambling Through the Skies:Dnoces, Navi, and Regor.” Sky & Telescope,October, 1994, pp. 63-65.

Krupp, E. C. “Rambling Through the Skies:Looking Up to the Gold Standard.” Sky &Telescope, May, 2004, pp. 50-52.

Kunitzsch, Paul, and Smart, Tim. Short Guideto Modern Star Names and Their Deriva -tions. Wiesbaden: Otto Harrassowitz, 1986.

Lachieze-Rey, Marc and Luminet, Jean-Pierre.Celestial Treasury: From the Music of TheSpheres to the Conquest of Space. Both edi-tions printed in France. French edition:Bibliotheque Nationale de France/Seuil,1998. English edition: Cambridge Univer-sity Press, 2001.

McGourty, Christine. “Lost Letters’ NeptuneRevelations.” http://news.bbc.co.uk/2/low/science/nature/2936663.stm, April 10,2003.

Ridpath, Ian. “The Origin of Our Constel-lations.” M e r c u r y, November/December1990. pp. 163-171.

Ridpath, Ian. Star Tales. New York: UniverseBooks, 1988.

Rudaux, Lucien, and De Vaucouleurs, G.Larousse Encyclopedia of Astronomy. Trans-lated from the French publication, prod-uct of Librairie Larousse. New York: Pro-metheus Press, 1959, p. 302.

Schaaf, Fred. “Star Names New and Old.” Sky& Telescope, April, 2003, p. 90.

Schmadel, Lutz D. Dictionary of Minor PlanetNames. New York: Springer-Verlag, 2003.

Sheehan, William. The Planet Mars: A Historyof Observation and Discovery. Tucson: Uni-versity of Arizona Press. 1996.

Stooke, Philip. “The Earliest Maps of Venus.”Sky & Telescope, August, 1992, pp. 156-158.

Shostak, Seth. Sharing the Universe: Per -spectives on Extraterrestrial Life. B e r k e l e y :Berkeley Hills Books, 1998.

United Nations General Assembly. A g r e e -ment Governing the Activities of States onthe Moon and Other Celestial Bodies, Parts 1and 2 and Part 3 (two volumes). AdoptedDecember 5, 1979. Reprinted with intro-ductory comments for the U.S. CommitteeOn Commerce, Science and Transpor-tation, May 1980, at the request of Hon.Howard W. Cannon, Chairman, 96th Con-gress, 2nd Session.

Voyager III Dynamic Sky Simulator comput-er software for Windows. Carina Software,2002. (http://www.carinasoft.com.)

Whitaker, Ewen A. Mapping and Naming theMoon: A History of Lunar Cartography andNomencla tu re . Cambridge, UK: PressSyndicate of the University of Cambridge,First published 1999; Reprinted 2000. C


how astronomical objects are named€¦ · dutchman gerardus mercator (1512-1594) on his 1551...

Documents