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WASP-42 b

The only known planet of WASP-42, a small orange star in the constellation of Centaurus. The system lies some 522 light years from the Sun, though with some considerable uncertainty over its precise distance. WASP-42 is a dwarf star, comparatively rather cooler than the Sun and about ninety percent of its diameter.

The planet WASP-42 b is physically a gas giant, marginally larger than Jupiter, though considerably less dense. It orbits extremely close to its parent star, at a distance of just 0.05 AU (that is, about eight times closer to WASP-42 than Mercury is to the Sun). This means that surface temperatures on the planet are extreme, estimated at about 1,000 K. Due to its proximity to the star, the orbit of WASP-42 b is very rapid, with the planet completing one circuit of the star in just under five days.