via ScienceDaily, the European COROT space observatory has discovered a very unusual object orbiting a distant star. While a number of exoplanets have been discovered in short period orbits, this object defies classification due to its unusual mass. Every one of the "hot Jupiters" found by astronomers so far range in size up to 12 Jupiter masses, while failed stars, so-called brown dwarfs, start off at around 70 Jupiter masses. This object, called COROT-exo-3b, is twenty Jupiter masses, yet is around the same diameter. This makes the object around twice as dense as lead.
"The object, named COROT-exo-3b, is about the size of Jupiter, but packs more than 20 times the mass. It takes only 4 days and 6 hours to orbit its parent star, which is slightly larger than the Sun. COROT-exo-3b was found as the satellite observed the drop in the brightness of the star each time the object (COROT-exo-3b) passed in front. "We were taken by surprise when we found this massive object orbiting so close to its parent star", said Dr Magali Deleuil from the Laboratoire d'Astrophysique de Marseille (LAM), leader of the team that made the discovery. She added, "COROT-exo-3b is really unique - we’re still debating its nature."