Discovery date 25 January 2012 Discovery status Published | Discoverer(s) Jason Steffen et al. | |
Discovery site Kepler Space Observatory | ||
Kepler-28b is an extrasolar planet orbiting the star Kepler-28. It is a transiting planet that is smaller than Jupiter that orbits very closely to Kepler-28.
Contents
Host star
Kepler-28 is the host star of Kepler-28b, and is alternatively known as KOI-870 and KIC 6949607. The star is smaller, less massive, and cooler than the Sun, with (respectively) a radius 0.7 times of the Sun; a mass 0.75 times of the Sun; and an effective temperature of 4590 K. The star has a high metallicity with relation to the Sun, as it has a metallicity of [M/H] = 0.34. With an apparent magnitude of 15.05, Kepler-28 is effectively invisible to the naked eye from Earth.
Characteristics
Kepler-28b is a gas giant that, at its maximum could be 1.51 times the mass of Jupiter. However, at 0.32 Jupiter radii, Kepler-28b is far smaller than Jupiter. The planet orbits at a distance of 0.062 AU, which corresponds roughly to 6% of the average distance that separates the Sun and Earth, and completes each orbit every 5.9123 days. The planet, which transits its host star, completely passes across the face of Kepler-28 in 2.77 hours. The ratio of its orbital period with that of Kepler-28c is 1.52.