COROT's first planet
ESA's planet-hunting satellite COROT bagged its first exoplanet in observations of the star COROT-Exo-1, located 1,500 light-years away in the constellation Monoceros. This telltale drop in the brightness of the star indicates that a planet -- in this case, a "hot Jupiter" gas giant about 1.3 times the mass of Jupiter -- transited the star, momentarily darkening its disk. From the speed of its transit, COROT's scientists determined that the planet orbits close to the star with an orbital period of only 1.5 days.