WASP-12b
Size comparison of WASP-12b (right) with Jupiter | |
| Discovery | |
|---|---|
| Discovered by | Cameron et al. (SuperWASP) |
| Discovery site | SAAO |
| Discovery date | April 2008 |
| Transit | |
| Orbital characteristics | |
| 0.0234+0.00056 −0.00050 AU | |
| Eccentricity | 0.049 ± 0.015 |
| 1.0914199±0.0000002 d | |
| Inclination | 81.92°±1.51° |
| −74°+13° −10° | |
| Star | WASP-12 |
| Physical characteristics | |
| 1.937±0.056 RJ | |
| Mass | 1.47+0.076 −0.069 MJ |
Mean density | 0.266 g/cm3 |
| 3.004±0.015 g | |
| Temperature | 3128+64 −68 K (2885+64 −68 °C, 5225+147 −155 °F) |
WASP-12b is a hot Jupiter (a class of extrasolar planets) orbiting the star WASP-12, discovered in April of 2008, by the SuperWASP planetary transit survey. The planet takes only a little over one Earth day to orbit its star, in contrast to about 365.25 days for the Earth to orbit the Sun. Its distance from the star (approximately 3.5 million kilometers [2.2 million miles; 0.023 astronomical units]) is only the Earth's distance from the Sun, with an eccentricity the same as Jupiter's. Consequently, it has one of the lowest densities for exoplanets ("inflated" by the flux of energy from the star). On December 3, 2013, scientists working with the Hubble Space Telescope (HST) reported detecting water in the atmosphere of the exoplanet. In July 2014, NASA announced finding very dry atmospheres on three exoplanets (HD 189733b, HD 209458b, WASP-12b) orbiting sun-like stars.
In September 2017, researchers working on the HST announced that WASP-12b reflects just 6% of the light that shines on its surface. As a result, the exoplanet has been described as "black as asphalt" and as "pitch black", although visually it would actually appear intensely bright due to its closeness to its star.