Contains TrES-2, which was the most massive nearby transiting planet until the discovery of Hat-P-2 b. It has a large radius for a planet not considered inflated. A large ground-based telescope method of observation was pioneered on this planet. Since its in Keplar's field of view, it was observed by it as a test subject and dubbed Kepler1b. A second planet is possibly responsible for fluctuations in the first's inclination. Kepler determined that it is the darkest known planet, blacker than coal, due to its extremely low dimming and brightening detected during transits. It would appear black except for some faint red tinge. This conflicts with current theories, which thought that a Hot Jupiter could only get as dark as Mercury. It appears that the planet is too hot for reflective clouds to form and instead its atmosphere contains light-absorbing chemicals. An off-the-cuff nickname Erebus (Greek god of darkness) has been suggested. It was also the first planet whose phases have been detected.