XO-2b is an extrasolar planet orbiting the star XO-2 in the constellation Lynx. It was detected using the transit method in 2007 by Burkes et al. It was the second planet discovered by the XO telescope, dependent on the XO Project.

It is a Jovian planet, as are those found using the transit method. Its orbit takes 2.6 days to complete, at a distance of 0.039 AU. In particular, it is a hot Jupiter-type planet, because it is very close to its star, having a surface temperature of approximately 1200 K. It has a mass equal to 57% of that of Jupiter, and a radius of 97%. The radius, relatively large for its mass, may be due to the extreme temperature, which would expand its atmosphere. It has a density of only 820 kg/m³.


Observations of XO-2b

Collaborative projects