PUBLIC OBSERVING Starry Night Observation Party

Hutchinson, KS Hobart-Detter Field

Carey Park August 28

5:00—10:30 PM

President: Rick Heschmeyer

rcjbm@sbcglobal.net Treasurer:

Dr. Steve Shawl Shawl@ku.edu

University Advisor: Dr. Bruce Twarog btwarog@ku.edu

Webmaster: Gary Webber

gwebber@ku.edu Observing Clubs

Doug Fay dfay@ku.edu

Report from the Officers: The Cosmosphere in Hutchinson has released the schedule for its Starry Night Observation Party. This year's event will be Saturday August 28 from 5 pm to ~10:30, with Saturday, Sept 4 as an inclement weather back-up date. It will be lo-cated in the same place, Hobart-Detter ball field in Carey Park on the south side of Hutchinson. Like last year, it will be open to the public and will include a range of space-related activities. We had a nice showing from the AAL at last year's event. If you are interested in attending this summer's event, let Rick know, and he will forward numbers to Brad

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Volume 36 Number 08 August 2010

INSIDE THIS ISSUE

Nemesis (continued) 2

Cometary Planets 3

NASA Space Place 4

Seven Sisters Get WISE 5

Black Holes (continued) 5

Nemesis (continued) 5

High-Velocity Stars 6

Buckyballs Found 7

Planets (continued) 8

Black Holes Jerked Twice 9

Buckyballs (continued) 10

High-Velocity (continued) 8

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Of Local Interest: The Death of Nemesis: The Sun's Distant, Dark Com-panion —The Physics ArXiv Blog

The data that once suggested the Sun is orbited by a distant dark companion now raises even more questions

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A Stellar Welcome to a new member of the AAL

Richard G. Reber

About the Astronomy Associates of Lawrence

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The club is open to all people interested in sharing their love for astronomy. Monthly meetings are typically on the second Fri-day of each month and often feature guest speakers, presentations by club members, and a chance to exchange amateur as-tronomy tips. Approximately the last Sunday of each month we have an open house at the Prairie Park Nature Center. Periodic

star parties are scheduled as well. For more information, please contact the club officers:our president, Rick Heschmeyer at rcjbm@sbcglobal.net, our webmaster, Gary Webber, at gwebber@ku.edu, or our faculty advisor, Prof. Bruce Twarog at

btwarog@ku.edu. Because of the flexibility of the schedule due to holidays and alternate events, it is always best to check the Web site for the exact Fridays and Sundays when events are scheduled. The information about AAL can be found at

http://www.ku.edu/~aal.

Copies of the Celestial Mechanic can also be found on the web at http://www.ku.edu/~aal/celestialmechanic

Nuest as we get closer to the event date. Heart of America Star Party: Sponsored by the Astronomical Society of Kansas City (www.askc.org), this year's Heart of America Star Party will run September 2 thru 9th. Yes, that's through Labor Day weekend! There will be catered meals, multiple speakers, and hands-on classes. This will be our 5th year. Previous years have had up to 140 attendees from as far away as Virginia, Wyoming, Minnesota, and Texas. Naked eye limiting magnitude is typi-cally around 6.8. Check out our web site at www.hoasp.org Revisions and updates for 2010's star party will be coming shortly. Address: Astronomical Society of Kansas City's Dark Sky Site City: Butler, Missouri: 80 miles south of Kansas City. As always, if anyone has any ideas, suggestions, or input on how we can make the club better, please contact Rick (rcjbm@sbcglobal.net). Enjoy the summer while it lasts. We will return to our normal meeting schedule in Sept.

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Over the last 500 million years or so, life on Earth has been threatened on many occasions; the fossil record is littered with ex-tinction events. What's curious about these events is that they seem to occur with alarming regularity.

The periodicity is a matter of some controversy among paleobiologists but there is a growing consensus that something of enor-mous destructive power happens every 26 or 27 million years. The question is what?

In this blog, we've looked at various ideas such as the Sun's passage through the various spiral arms of the Milky Way galaxy (it turns out that this can't explain the extinctions because the motion doesn't have had the right periodicity).

But another idea first put forward in the 1980s is that the Sun has a distant dark companion called Nemesis that sweeps through the Oort cloud every 27 million years or so, sending a deadly shower of comets our way. It's this icy shower of death that causes the extinctions, or so the thinking goes.

On July 12, Adrian Melott at the University of Kansas and Richard Bambach at the Smithsonian Institute in Washington DC re-examine the paleo-record to see if they can get a more accurate estimate of the orbit of Nemesis.

Their work throws up a surprise. They have brought together a massive set of extinction data from the last 500 million years, a period that is twice as long as anybody else has studied. And their analysis shows an excess of extinctions every 27 million years, with a confidence level of 99%.

That's a clear, sharp signal over a huge length of time. At first glance, you'd think it clearly backs the idea that a distant dark object orbits the Sun every 27 million years.

But ironically, the accuracy and regularity of these events is actually evidence against Nemesis' existence, say Melott and Bam-buch.

That's because Nemesis' orbit would certainly have been influenced by the many close encounters we know the Sun has had with other stars in the last 500 million years.

These encounters would have caused Nemesis' orbit to vary in one of two ways. First, the orbit could have changed suddenly so that instead of showing as a single the peak, the periodicity would have two or more peaks. Or second, it could have changed gradually by up 20 per cent, in which case the peak would be smeared out in time.

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Cometary Planets? HST Press Release

As if the debate over what is and what is not a planet hasn't gotten confusing enough, Hubble Space Telescope as-tronomers have now confirmed the existence of a tortured, baked object that could be called a "cometary planet." The gas giant planet, dubbed HD 209458b, is orbiting so close to its star that its heated atmosphere is escaping away into space. Now, observations by the new Cosmic Origins Spectrograph (COS) aboard NASA's Hubble suggest that power-ful stellar winds are sweeping the castoff material behind the scorched planet and shaping it into a comet-like tail.

"Since 2003 scientists have theorized that the lost mass is being pushed back into a tail and have even calculated what the tail looks like," says astronomer Jeffrey Linsky of the University of Colorado in Boulder, leader of the COS study. "We think we have the best observational evidence to support that theory. We have measured gas coming off the planet at specific speeds, some coming toward Earth. The most likely interpretation is that we have measured the ve-locity of material in a tail."

HD 209458b weighs slightly less than Jupiter, but it orbits 100 times closer to its star than Jupiter does. The roasted planet zips around in a mere 3.5 days. (In contrast, our solar system's speedster, Mercury, orbits the Sun in a leisurely 88 days.) The planet is one of the most intensely scrutinized extrasolar planets because it is one of the few known alien worlds that can be seen passing in front of, or transiting, its star. The transit causes the starlight to dim slightly. In fact, the gas giant is the first alien world discovered to transit its parent star. It orbits the star HD 209458, located 153 light-years from Earth.

Linsky and his team used COS to analyze the planet's atmosphere during transiting events. During a transit, astrono-mers can study the structure and chemical makeup of a planet's atmosphere by sampling the starlight that passes through it. The dip in starlight due to the planet's passage, excluding the planet's atmosphere, is very small, only 1.5 percent. When the atmosphere is added, the dip jumps to 8 percent, indicating a bloated atmosphere.

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The Sun Can Still Re-mind Us Who’s Boss

by Dr. Tony Phillips

Grab your cell phone and take a good long look. It's indispensible, right? It tells time, surfs the web, keeps track of your appointments and, by the way, also makes phone calls. Modern people can hardly live without one. One good solar flare could knock it all out. “In the 21st century, we’re increasingly dependent on technology,” points out Tom Bogdan, director of NOAA's Space Weather Prediction Center in Boulder, Colorado. “This makes solar activity an important part of our daily lives.” Indeed, bad space weather can knock out power systems, telecommunications, financial and emergency services—basically, any-thing that needs electronics to work. That’s why NOAA is building a new fleet of “space weather stations,” the GOES-R satellites. “GOES-R will bring our existing fleet of weather satellites into the 21st century,” says Bogdan. “They're designed to moni-tor not only Earth weather, but space weather as well.” NOAA's existing fleet of Geostationary Operational Environmental Satellites (GOES) already includes some space weather capabilities: solar ultraviolet and X-ray telescopes, a magnetome-ter and energetic particle sensors. GOES-R will improve upon these instruments and add important new sensors to the mix. One of Bogdan’s favorites is a particle detector named “MPS-Low,” which specializes in sensing low-energy (30 ev – 30 keV) particles from the sun.

Who cares about low-energy particles? It turns out they can be as troublesome as their high-energy counterparts. Pro-tons and other atomic nuclei accelerated to the highest energies by solar flares can penetrate a satellite’s exterior surface, causing all kinds of problems when they reach internal electronics. Low-energy particles, particularly electrons, can’t penetrate so deeply. Instead, they do their damage on the outside.

As Bogdan explains, “Low-energy particles can build up on the surfaces of spacecraft, creating a mist of charge. As volt-ages increase, sparks and arcs can zap electronics—or emit radio pulses that can be misinterpreted by onboard com-puters as a command.” The Galaxy 15 communications satellite stopped working during a solar wind storm in April 2010, and many researchers believe low-energy particles are to blame. GOES-R will be able to monitor this population of parti-cles and alert operators when it’s time to shut down sensitive systems.

“This is something new GOES-R will do for us,” says Bogdan. The GOES-R magnetometer is also a step ahead. It will sample our planet’s magnetic field four times faster than its predecessors, sensing vibrations that previous GOES satel-lites might have missed. Among other things, this will help forecasters anticipate the buildup of geomagnetic storms.

And then there are the pictures. GOES–R will beam back striking images of the sun at X-ray and extreme UV wavelengths. These are parts of the electromagnetic spectrum where solar flares and other eruptions make themselves known with bright flashes of high-energy radia-tion. GOES-R will pinpoint the flashes and identify their sources, allowing forecasters to quickly assess whether or not Earth is in the “line of fire.”

They might also be able to answer the ques-tion, Is my cell phone about to stop working?The first GOES-R satellite is scheduled for launch in 2015. Check www.goes-r.gov for updates. Space weather comes down to Earth in the clear and fun explanation for young peo-ple on SciJinks, http://scijinks.gov/space-weather-and-us.

This article was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics

and Space Administration. In spite of Earth’s protective magnetosphere, solar storms can wreak havoc with Earth satellites and other expensive electronics on the ground.

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But the data indicates that the extinctions occur every 27 million years, as regular as clockwork. "Fossil data, which motivated the idea of Nemesis, now militate against it," say Melott and Bambuch.

That means something else must be responsible. It's not easy to imagine a process in our chaotic interstellar envi-ronment that could have such a regular heart beat; perhaps the answer is closer to home.

There is a smidgeon of good news. The last extinction event in this chain happened 11 million years ago so, in theory at least, we have plenty of time to work out where the next catastrophe is coming from.

Either way, the origin of the 27 million year extinction cycle is heating up to become one of the great scientific mys-teries of our time.

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the top-right and bottom-left. Since the gas falling onto the black hole was not aligned with the spin of the black hole, the spin axis of the black hole rapidly changed direction, and the jets then pointed in a roughly top-left to bot-tom-right direction, creating cavities in the hot gas and radio emission in this direction. Then, either a merging of the two central black holes from the colliding galaxies, or more gas falling onto the black hole caused the spin axis to jerk around to its present direction in roughly a left to right direction. These types of changes in the angle of the spin of a supermassive black hole have previously been suggested to explain X-shaped radio galaxies, but no convinc-ing case has been made in any individual case.

"If we're right, our work shows that jets and cavities are like cosmic fossils that help trace the merger history of an active supermassive black hole and the galaxy it lives in," said Hodges-Kluck. "If even a fraction of X-shaped radio galaxies are produced by such "spin-flips", then their frequency may be important for estimating the detection rates with gravitational radiation missions."

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SEVEN SISTERS GET WISE: The Pleiades Seen with the WISE Infrared Satellite

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HST Clarifies High Velocity Stars

A hundred million years ago, a triple-star system was traveling through the bustling center of our Milky Way galaxy when it made a life-changing misstep. The trio wandered too close to the galaxy's giant black hole, which captured one of the stars and hurled the other two out of the Milky Way. Adding to the stellar game of musical chairs, the two outbound stars merged to form a super-hot, blue star.

This story may seem like sci-ence fiction, but astronomers using NASA's Hubble Space Telescope say it is the most likely scenario for a so-called hypervelocity star, known as HE 0437-5439, one of the fast-est ever detected. It is blazing across space at a speed of 1.6 million miles (2.5 million kilo-meters) an hour, three times faster than our Sun's orbital velocity in the Milky Way. Hub-ble observations confirm that the stellar speedster hails from the Milky Way's core, settling some confusion over where it originally called home.

Most of the roughly 16 known hypervelocity stars, all discov-ered since 2005, are thought to be exiles from the heart of our galaxy. But this Hubble result is the first direct obser-vation linking a high-flying star to a galactic center origin.

"Using Hubble, we can for the first time trace back to where the star comes from by measuring the star's direction of motion on the sky. Its motion points directly from the Milky Way center," says astronomer Warren Brown of the Harvard-Smithsonian Center for Astro-physics in Cambridge, Mass., a member of the Hubble team that observed the star. "These exiled stars are rare in the Milky Way's population of 100 billion stars. For every 100 million stars in the galaxy lurks one hypervelocity star."

The movements of these unbound stars could reveal the shape of the dark matter distribution surrounding our galaxy. "Studying these stars could provide more clues about the nature of some of the universe's unseen mass, and it could help astronomers better understand how galaxies form," says team leader Oleg Gnedin of the University of Michigan in Ann Arbor. "Dark matter's gravitational pull is measured by the shape of the hyperfast stars' trajectories out of the Milky Way."

The stellar outcast is already cruising in the Milky Way's distant outskirts, high above the galaxy's disk, about 200,000 light-years from the center. By comparison, the diameter of the Milky Way's disk is approximately 100,000 light-years. Using Hubble to measure the runaway star's direction of motion and determine the Milky Way's core as its starting point, Brown and Gnedin's team calculated how fast the star had to have been ejected to reach its current location.

"The star is traveling at an absurd velocity, twice as much as the star needs to escape the galaxy's gravitational field," explains Brown, a hypervelocity star hunter who found the first unbound star in 2005. "There is no star that travels that quickly under normal circumstances — something exotic has to happen."

There's another twist to this story. Based on the speed and position of HE 0437-5439, the star would have to be 100 million years old to have journeyed from the Milky Way's core. Yet its mass — nine times that of our Sun — and blue color mean that it should have burned out after only 20 million years — far shorter than the transit time it took to get to its current location.

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NASA Telescope Finds Elusive Buckyballs in Space for First Time Astronomers using NASA's Spitzer Space Telescope have discovered carbon molecules, known as "buckyballs," in space for the first time. Buckyballs are soccer-ball-shaped molecules that were first observed in a laboratory 25 years ago.

They are named for their resemblance to architect Buckminster Fuller's geodesic domes, which have interlocking

circles on the surface of a partial sphere. Buckyballs were thought to float around in space, but had escaped detec-tion until now.

"We found what are now the largest molecules known to exist in space," said astronomer Jan Cami of the University of Western Ontario, Canada, and the SETI Institute in Mountain View, Calif. "We are particularly excited because they have unique properties that make them important players for all sorts of physical and chemical processes going on in space." Cami has authored a paper about the discovery that will appear online Thursday in the journal Sci-ence.

Buckyballs are made of 60 carbon atoms arranged in three-dimensional, spherical structures. Their alternating pat-terns of hexagons and pentagons match a typical black-and-white soccer ball. The research team also found the more elongated relative of buckyballs, known as C70, for the first time in space. These molecules consist of 70 car-bon atoms and are shaped more like an oval rugby ball. Both types of molecules belong to a class known officially as buckminsterfullerenes, or fullerenes.

The Cami team unexpectedly found the carbon balls in a planetary nebula named Tc 1. Planetary nebulas are the remains of stars, like the sun, that shed their outer layers of gas and dust as they age. A compact, hot star, or white dwarf, at the center of the nebula illuminates and heats these clouds of material that has been shed.

The buckyballs were found in these clouds, perhaps reflecting a short stage in the star's life, when it sloughs off a puff of material rich in carbon. The astronomers used Spitzer's spectroscopy instrument to analyze infrared light from the planetary nebula and see the spectral signatures of the buckyballs. These molecules are approximately room temperature -- the ideal temperature to give off distinct patterns of infrared light that Spitzer can detect. Ac-cording to Cami, Spitzer looked at the right place at the right time. A century from now, the buckyballs might be too cool to be detected.

The data from Spitzer were compared with data from laboratory measurements of the same molecules and showed (Continued on page 10)

The most likely explanation for the star's blue color and extreme speed is that it was part of a triple-star system that was involved in a gravitational billiard-ball game with the galaxy's monster black hole. This concept for imparting an escape velocity on stars was first proposed in 1988. The theory predicted that the Milky Way's black hole should eject a star about once every 100,000 years.

Brown suggests that the triple-star system contained a pair of closely orbiting stars and a third outer member also gravi-tationally tied to the group. The black hole pulled the outer star away from the tight binary system. The doomed star's momentum was transferred to the stellar twosome, boosting the duo to escape velocity from the galaxy. As the pair rocketed away, they went on with normal stellar evolution. The more massive companion evolved more quickly, puffing up to become a red giant. It enveloped its partner, and the two stars spiraled together, merging into one superstar — a blue straggler.

"While the blue straggler story may seem odd, you do see them in the Milky Way, and most stars are in multiple sys-tems," Brown says.

This vagabond star has puzzled astronomers since its discovery in 2005 by the Hamburg/European Southern Observa-tory sky survey. Astronomers had proposed two possibilities to solve the age problem. The star either dipped into the Fountain of Youth by becoming a blue straggler, or it was flung out of the Large Magellanic Cloud, a neighboring galaxy.

In 2008 a team of astronomers thought they had solved the mystery. They found a match between the exiled star's chemical makeup and the characteristics of stars in the Large Magellanic Cloud. The rogue star's position also is close to the neighboring galaxy, only 65,000 light-years away. The new Hubble result settles the debate over the star's birth-place.

Astronomers used the sharp vision of Hubble's Advanced Camera for Surveys to make two separate observations of the wayward star 3 1/2 years apart. Team member Jay Anderson of the Space Telescope Science Institute in Baltimore, Md., developed a technique to measure the star's position relative to each of 11 distant background galaxies, which form a reference frame.

Anderson then compared the star's position in images taken in 2006 with those taken in 2009 to calculate how far the star moved against the background galaxies. The star appeared to move, but only by 0.04 of a pixel (picture element) against the sky background. "Hubble excels with this type of measurement," Anderson says. "This observation would be challenging to do from the ground." The team is trying to determine the homes of four other unbound stars, all located on the fringes of the Milky Way.

"We are targeting massive 'B' stars, like HE 0437-5439," says Brown, who has discovered 14 of the 16 known hyperve-locity stars. "These stars shouldn't live long enough to reach the distant outskirts of the Milky Way, so we shouldn't ex-pect to find them there. The density of stars in the outer region is much less than in the core, so we have a better chance to find these unusual objects."

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COS detected the heavy elements carbon and silicon in the planet's super-hot (2,000-degree-Fahrenheit) atmosphere. This detection reveals that the parent star is heating the entire atmosphere, dredging up the heavier elements and al-lowing them to escape the planet. The COS data also showed that the material leaving the planet was not all traveling at the same velocity. "We found gas escaping at high velocities, with a large amount of this gas flowing toward us at 22,000 miles per hour," Linsky explains. "This large gas flow is likely gas swept up by the stellar wind to form the comet-like tail trailing the planet."

Hubble's newest spectrograph, with its ability to probe a planet's chemistry at ultraviolet wavelengths that are not acces-sible to ground-based telescopes, is proving to be an important instrument for probing the atmospheres of "hot Jupiters" like HD 209458b. Astronomers have also used COS to sample the atmosphere of another baked planet, WASP-12b, whose puffy atmosphere is spilling onto its star.

Another Hubble instrument, the Space Telescope Imaging Spectrograph (STIS), observed HD 209458b in 2003. The STIS data showed an active, evaporating atmosphere, and a comet-tail-like structure was suggested as a possibility. But STIS wasn't able to obtain the spectroscopic detail necessary to show an earthward-moving component of the gas during transits. Because of COS's unique combination of very high ultraviolet sensitivity and good spectral resolution, the earthward moving component of the gas — the tail — could be directly detected for the first time.

Although this "extreme" planet is getting roasted by its star, it won't be destroyed anytime soon. "It will take about a tril-lion years for the planet to evaporate," Linsky says.

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Black Hole Jerked Around Twice Chandra Press Release Scientists have found evidence that a giant black hole has been jerked around twice, causing its spin axis to point in a different direction from before. This discovery, made with new data from NASA's Chandra X-ray Observatory, might ex-

plain several mysterious-looking ob-jects found throughout the Universe. The axis of the spinning black hole is thought to have moved, but not the black hole itself, so this result differs from recently published work on recoil-ing black holes. "We think this is the best evidence ever seen for a black hole having been jerked around like this," said Edmund Hodges-Kluck of the University of Maryland. "We're not exactly sure what caused this behav-ior, but it was probably triggered by a collision between two galaxies." A team of astronomers used Chandra for a long observation of a galaxy known as 4C+00.58, which is located about 780 million light years from Earth. Like most galaxies, 4C+00.58 contains a supermassive black hole at its center, but this one is actively pull-ing in copious quantities of gas. Gas swirling toward the black hole forms a disk around the black hole. Twisted magnetic fields in the disk generate strong electromagnetic forces that propel some of the gas away from the disk at high speed, producing radio jets. A radio image of this galaxy shows a

bright pair of jets pointing from left to right and a fainter, more distant line of radio emission running in a different direction. More specifically, 4C+00.58 belongs to a class of "X-shaped" galaxies, so called because of the outline of their radio emission. The new Chandra data have allowed astronomers to determine what may be happening in this system, and perhaps in others like it. The X-ray image re-veals four different cavities around the black hole. These cavities come in pairs: one in the top-right and bottom-left, and another in the top-left and bottom-right. When combined with the orientation of the radio jets, the complicated geometry revealed in the Chandra image may tell the story of what happened to this supermassive black hole and the galaxy it inhabits. "We think that this black hole has quite a history," said Christopher Reynolds of the University of Maryland in College Park. "Not once, but twice, something has caused this black hole to change its spin axis." According to the scenario presented by Hodges-Kluck and his colleagues, the spin axis of the black hole ran along a diagonal line from top-right to bottom-left. After a collision with a smaller galaxy, a jet powered by the black hole ig-nited, blowing away gas to form cavities in the hot gas to

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This image shows the effects of a giant black hole that has been flipped around twice, causing its spin axis to point in a different direction from before. The optical image, from the Sloan Digital Sky Survey, is centered on a radio galaxy named 4C +00.58. The smaller image to the right (expanded below) shows a close-up view of this galaxy in X-rays (in gold) from the Chandra X-ray Observatory, and radio waves (in blue) from the Very Large Array.

AAL Astronomy Associates of Lawrence

University of Kansas Malott Hall 1251 Wescoe Hall Dr, Room 1082 Lawrence, KS 66045-7582

Celestial Mechanic August 2010

a perfect match.

"We did not plan for this discovery," Cami said. "But when we saw these whopping spectral signatures, we knew im-mediately that we were looking at one of the most sought-after molecules."

In 1970, Japanese professor Eiji Osawa predicted the existence of buckyballs, but they were not observed until lab experiments in 1985. Researchers simulated conditions in the atmospheres of aging, carbon-rich giant stars, in which chains of carbon had been detected. Surprisingly, these experiments resulted in the formation of large quantities of buckminsterfullerenes. The molecules have since been found on Earth in candle soot, layers of rock and meteorites.

The study of fullerenes and their relatives has grown into a busy field of research because of the molecules' unique strength and exceptional chemical and physical properties. Among the potential applications are armor, drug delivery and superconducting technologies.

Sir Harry Kroto, who shared the 1996 Nobel Prize in chemistry with Bob Curl and Rick Smalley for the discovery of buckyballs, said, "This most exciting breakthrough provides convincing evidence that the buckyball has, as I long sus-pected, existed since time immemorial in the dark recesses of our galaxy."

Previous searches for buckyballs in space, in particular around carbon-rich stars, proved unsuccessful. A promising case for their presence in the tenuous clouds between the stars was presented 15 years ago, using observations at optical wavelengths. That finding is awaiting confirmation from laboratory data. More recently, another Spitzer team reported evidence for buckyballs in a different type of object, but the spectral signatures they observed were partly contaminated by other chemical substances.

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