Are Some Distant Planets a Mirage?

“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”.

-- Alexandre Santerne, Instituto de Astrofísica e Ciências do Espaço, discussing a new study by his team - SOPHIE velocimetry of Kepler transit candidates XVII. The physical properties of giant exoplanets within 400 days of period.  The team used SOPHIE (Spectrographe pour l’Observation des Phénomènes des Intérieurs stellaires et des Exoplanètes) to conduct its study, which is located in an observatory in france.