Half of Kepler’s giant exoplanet candidates are false positives, study finds

An international team led by Alexandre Santerne from Instituto de Astrofísica e Ciências do Espaço (IA), made a 5-year radial velocity campaign of Kepler's giant exoplanet candidates, using the SOPHIE4spectrograph (Observatory of Haute-Provence, France), and found that 52.3% were actually eclipsing binaries, while 2.3% were brown dwarfs.

Santerne (IA & University of Porto), first author of this paper commented: "It was thought that the reliability of the Kepler exoplanets detection was very good -- between 10 and 20% of them were not planets. Our extensive spectroscopic survey, of the largest exoplanets discovered by Kepler, shows that this percentage is much higher, even above 50%. This has strong implications in our understanding of the exoplanet population in the Kepler field."

www.sciencedaily.com...

This news is not as disappointing as it sounds. Scientists have been a bit over-confident in their public announcements of their findings in the past. Analyzing the vast amounts of data from Kepler is difficult, and there are still unresolved issues like the question of "jittering." Although this study ups the number of false positives, it opens up a whole new class of objects to study: extremely close binary systems. Can you imagine two stars orbiting around each other in a matter of days? They would eventually spiral in to each other and create a supernova.

Of course, the down side is that the billions and billions of planets out there that might harbor intelligent life has been reduced by half. Still pretty good odds though. It is probably safe to say that planetary systems are a nearly universal by product of star formation.

a reply to: DJW001

That ought to shut 'em up.

a reply to: DJW001

I wonder how many other studies were WAYYYYY off

originally posted by: FamCore
a reply to: DJW001

I wonder how many other studies were WAYYYYY off

Normally I would say "you would be surprised," but I have a feeling a more appropriate answer in this case would be "fewer than you suppose." One of the problems with contemporary science is that original work is more highly regarded than confirmatory work. Once a finding is published, there is little incentive for a researcher in that field to duplicate the work. This does not matter so much in "abstract" sciences like astrophysics, but in fields like biology, medicine, and neuroscience, the pressure to apply the research commercially is high, leading to potentially dangerous consequences.

a reply to: DJW001
I find it encouraging in that we might be learning something. Imagine how rare and difficult it must be to detect an extra stellar transit. Orbital periods, orbital plane alignments with Earth, orbital inclinations that revolve... I'm amazed they find any at all. To learn that it's more complicated than we originally thought, albeit discouraging, sounds like progress to me.

a reply to: Devino

Exactly. The next generation of telescopes might even be able to image exoplanets directly!

a reply to: DJW001

Well, that's why they were originally only labeled as "candidates" and not "confirmed planets".

This is the figure for the LARGEST exoplanets, the smaller ones may be very good still.