High Quality Content by WIKIPEDIA articles! Kepler-8b is the fifth of the first five exoplanets discovered by NASA`s Kepler spacecraft, which aims to discover planets in a region of the sky between the constellations Lyra and Cygnus that transit (cross in front of) their host stars. The planet is the hottest of the five. Kepler-8b was the first and only planet discovered in Kepler-8`s orbit, and is larger (though more diffuse) than Jupiter. It orbits its host star every 3.5 days. The planet also demonstrates the Rossiter-McLaughlin effect, where the planet`s orbit affects the redshifting of the spectrum of the host star. Kepler-8b was announced to the public on January 4, 2010 at a conference in Washington, D.C. after radial velocity measurements conducted at the W.M. Keck Observatory confirmed its detection by Kepler.