The XO project aims at detecting transiting exoplanets around bright stars
from the ground using small telescopes. The original configuration of XO
(McCullough et al. 2005) has been changed and extended as described here. The
instrumental setup consists of three identical units located at different
sites, each composed of two lenses equipped with CCD cameras mounted on the
same mount. We observed two strips of the sky covering an area of 520 deg2
for twice nine months. We build lightcurves for ~20,000 stars up to magnitude
R~12.5 using a custom-made photometric data reduction pipeline. The photometric
precision is around 1-2% for most stars, and the large quantity of data allows
us to reach a millimagnitude precision when folding the lightcurves on
timescales that are relevant to exoplanetary transits. We search for periodic
signals and identify several hundreds of variable stars and a few tens of
transiting planet candidates. Follow-up observations are underway to confirm or
reject these candidates. We found two close-in gas giant planets so far, in
line with the expected yield.Comment: Invited review, 25 pages, 16 figure
