A unexampled study has indicated that more than half of the possible giant exoplanet candidates obtain by NASA ’s Kepler Space Telescope are in reality not exoplanets at all . grant to the study , accepted for publication inAstronomy & Astrophysics , 52.3 percent wereeclipsing binaries(two stars orbiting one another)and 2.3 percent were conk out headliner known as brown dwarf ( although the eminence between a brown dwarf and a gargantuan planet is not entirely clear ) .
The team embark on by choose a representative sample from all the 8,826 candidate from the Kepler object of pastime list . The terminal selection was 129 large objective that freeze more than three percent of the star ’s light that could be observe multiple times as they orbit their superstar . The parent genius has to be undimmed enough to be observed bySOPHIE , the spectrogram used for this particular depth psychology at the Haute - Provence Observatory in France .
" It was recollect that the reliableness of the Kepler exoplanets sensing was very good – between 10 and 20 per centum of them were not planets , " jumper cable author Alexandre Santerne from the Institute of Astrophysics and Space Sciences said in astatement . " Our wide spectroscopic survey , of the largest exoplanets get word by Kepler , show that this part is much eminent , even above 50 percent . This has strong implications in our understanding of the exoplanet population in the Kepler champaign . "
possible exoplanet discoveries are often follow by detailed spectroscopic observation that allow astronomers to confirm if the object is a planet or not , as well as provide estimates for the mass . A smaller star revolve a orotund star topology or brown dwarfs can mimic a elephantine transiting exoplanet , so a spectroscopic study like this one is very important in confirming the true nature of exoplanet candidates .
" After 20 yr of explore planets as heavy as Jupiter around other suns , we still have a good deal of questions left open , " Santerne added . " For example , we do n’t read what is the physical mechanics that forms Jupiter - corresponding planets with orbital period as small as a few 24-hour interval . It is like if our one-year gyration around the Sun would last only a few days – imagine your old age ! We also do n’t understand why some of these elephantine planet are so puffy . "
By using the sizing information fromKeplerand the mass from SOPHIE , the team was capable to reckon the bulk compactness of the confirmed exoplanets , and it turns out that not all giant planets are as tumid as uranologist thought they were . More data is necessary to translate these hot Jupiters and to precisely depict them in planetary formation and phylogeny theories .
