Kepler-45, formerly known as KOI-254, is a star in the northern constellation of Cygnus. It is located at the celestial coordinates: right ascension , declination . With an apparent visual magnitude of 16.88, this star is too faint to be seen with the naked eye.
The star is exhibiting strong starspot activity, with 4.1% of its surface covered by starspots.
The "Hot Jupiter" class planet Kepler-45b, discovered in February 2011, is unusually massive for the M-class parent star. Its orbit is aligned within 11 degrees of rotational axis of the star.
Kepler-45b's transit lightcurve appears to deviate from what would be expected of a spherical planet. The deviation could be caused by material surrounding the planet, such as a dusty shell from an escaping atmosphere or a dense exoring.