Q4042007

Kepler-40b, formerly known as KOI-428b, is a hot Jupiter discovered in orbit around the star Kepler-40, which is about to become a red giant. The planet was first noted as a transit event by NASA's Kepler spacecraft. The Kepler team made data collected by its satellite publicly available, including data on Kepler-40; French and Swiss astronomers used the equivalent to one night of measurements on the SOPHIE échelle spectrograph to collect all the data needed to show that a planet was producing the periodic dimming of Kepler-40. The planet, Kepler-40b, is twice the mass of Jupiter and slightly larger than it in size, making it as dense as Neptune. The planet is also nearly thirteen times hotter than Jupiter and orbits five times closer to its star than Mercury is from the Sun.

==Observational history== Kepler-40 was first observed by the Kepler spacecraft, a NASA satellite that searches for planets in transit (crossing in front of and dimming) their host stars, from May 13, 2009, to June 15, 2009 in its first days of operation. The resulting light curve was made available to the public by the Kepler science team, revealing four transit events over 33.5 days.