Could Over Half of Kepler Giant Planet Detections be False Positives?

The Kepler space observatory has been in orbit around the sun since 2009, collecting data on 150,000 stars and searching for Earth-like planets in the Milky Way galaxy. The mission has identified 8,826 objects of interest. Of them, 4,696 are considered candidates, or possible planets. And 1,030 of the candidates have been confirmed.

According to a study focused on gas giants, however, that total may include more false positives than previously thought. The study, announced this week, has been accepted for publication in the journal Astronomy & Astrophysics.

"It was thought that the reliability of the Kepler exoplanets detection was very good -- between 10 and 20 percent of them were not planets," researcher Alexandre Santerne of the Portugal-based Institute of Astrophysics and Space Sciences, who led the international team behind the study, said in a statement.

"Our extensive spectroscopic survey, of the largest exoplanets discovered by Kepler, shows that this percentage is much higher, even above 50 percent. This has strong implications in our understanding of the exoplanet population in the Kepler field."

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