CoRoT-1b

CoRoT-1b (previously named CoRoT-Exo-1b) is a transiting extrasolar planet approximately 2,630 light-years away in the constellation of Monoceros. The planet was discovered orbiting the yellow dwarf star CoRoT-1 in May 2007. The planet was the first discovery by the French-led CoRoT Mission.

Discovery
CoRoT-1b was identified as the best planetary candidate from the CoRoT spacecraft initial run from February 6 to April 2, 2007. Follow-up photometry with the Wise Observatorys 1.0 m telescope and at the Canada–France–Hawaii Telescope eliminated many of the possible false positives for the transit signal. 9 radial velocity measurements of CoRoT-1 were made at Haute-Provence Observatory in March–April and October 2007 with the SOPHIE échelle spectrograph. The radial velocity data matched the CoRoT light curve and supported the planetary nature of CoRoT-1b and eliminated other possibilities such as background stars, grazing eclipsing binaries, or a triple system.

The discovery was publicly announced on May 3, 2007 and submitted for publication on January 4, 2008.

Characteristics
The planet is a large hot Jupiter, about 1.49 times the radius of Jupiter and approximately 1.03 times as massive, based on ground observations of the star. Its large size is due to its low density combined with the intense heating of its parent star causing the outer layers of the atmosphere to bloat.

Observation of phases
In May 2009 CoRoT-1b became the first extrasolar planet for which optical (as opposed to infrared) observations of phases were reported. These observations suggest that there is not significant heat transfer between the (tidally locked) night and day sides of the planet.