8/3/2019 Exoplanets discovered

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Exoplanets discoveredThe remains of two planets closely orbiting a dying star some 3,900 light years away have givenastronomers a glimpse of what may happen at the demise of our own solar system about fivebillion years from now.

Named KOI 55.01 and KOI 55.02, the planets orbit a sun that has passed the “red giant” stage —a star that has burned up most of its fuel and becomes larger and larger, according to the study,published recently in the journal Nature.

IN MINUTES News and events — visually 

Two survivors of their system

 3,900 light years from home

The host star

The two exoplanets, namedKOI 55.01 and KOI 55.02, are

likely the remnants of gasgiant planets that wereroasted by the bloating star’sfiery envelope.

They are now reduced totheir single dense core,consisting mostly of ironand other heavy elements.

The pair are respectively76% and 87% the size ofthe Earth, but wereprobably many times

larger.

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DIAMETER

DISTANCEFROM THE SUN

SURFACETEMPERATURE

9,662 km

897,000 km

576 hrs

8,000 - 9,000 ºC 8,000 - 9,000 ºC 15 ºC

823 hrs 36,525 days

1,137,000 km

150,000,000 km

11,060 km 12,713 km

ORBIT

KOI 55.01 KOI 55.02 EARTH

Having migrated so close, theexoplanets probably plunged deepinto the star’s envelope during thered giant phase, but survived. Thetwo observed bodies would then bethe dense cores of ancient giantplanets whose gaseousenvelopes werevaporized during theimmersion phase.

1 2 3

KOI 55.02

KIC 05807616

KOI 55.01

Reaching the end of itslife, it swelled into a redgiant, releasing a largeamount of gravitationalenergy.

NASA launched the Kepler SpaceTelescope in 2009 to survey aportion of our region of the MilkyWay galaxy to discover dozens ofEarth-size planets in or near thehabitable zone and determinehow many of the billions of stars

in our galaxy have such planets.

One light year equals 9,460 billion km

LyraCygnus

Milky Way

The host star of the twoexoplanets is a subdwarf Bstar, composed of the exposedcore of a red giant that haslost most of its fieryenvelope,and burns at about28,000 Kelvin,or 27,760 C.

Based on data from the U.S.satellite Kepler team ofresearchers by analyzingthe pulsations of the starKIC 05807616 (locatedin the vicinity of theconstellations ofCygnus and Lyra)

When our sun swells up to become ared giant it will engulf the Earth. If atiny planet like the Earth spends abillion years in an environment likethat, it will just evaporate. Only plan-ets with masses very much larger thanthe Earth, like Jupiter or Saturn, could

possibly survive. 

— Elizabeth Green of the University 

of Arizona’s Steward Observatory.

QMI AGENCY