Photometric searches for transiting planets: results and challenges

Abstract

Ground-based photometric surveys have led to the discovery of six transiting exoplanets, five of which were detected by the OGLE survey. The FLAMES multi-object spectrograph on the VLT has permitted a very efficient follow-up of the OGLE transit candidates, characterising not only the 5 planets but also more than 50 systems producing similar photometric signatures -- mainly eclipsing binaires. The presence of these ubiquitous "impostors" is a challenge for transit surveys. Another difficulty is the presence of red noise in the photometry, which implies a much lower sensitivity to transiting planets than usually assumed. We outline a method to estimate how the red noise will affect the expected yield of photometric transit searches.

arXiv comment12 pages. To appear in the proceedings of the meeting "Tenth anniversary of 51Peg b - status and prospects of hot Jupiter studies" at OHP, France, 22-26 August 2005