HAT-P-3b is an extrasolar planet that lies 457 light-years from Earth. It was discovered by the HATNet project, using the transit method.
Its mass is estimated at about 0.6 times that of Jupiter, with a heavy metal center of about 75 Earth masses.
https://arxiv.org/abs/0707.4268v1
Observations of HAT-P-3b
Collaborative projects
