WASP-8b
 Size comparison of WASP-8b with Jupiter. | |
| Discovery | |
|---|---|
| Discovered by | Cameron et al. (SuperWASP) |
| Discovery date | April 1, 2008 |
| Transit | |
| Orbital characteristics | |
| 0.0801+0.0014 −0.0016 AU | |
| Eccentricity | 0.31+0.0029 −0.0024 |
| 8.158715+0.000016 −0.000015 d | |
| Inclination | 88.55°+0.15° −0.17° |
| Star | WASP-8 |
| Physical characteristics | |
| 1.038+0.007 −0.047 RJ | |
| Mass | 2.244+0.079 −0.093 MJ |
Mean density | 1.85 g/cm3 (0.067 lb/cu in)[1] |
| 4.30 g | |
| Temperature | 1552 K[2] |
WASP-8b is an extrasolar planet discovered (with its parent star) in the SuperWASP batch -6b to -15b. On 1 April 2008, Dr. Don Pollacco of Queen's University Belfast announced them at the RAS National Astronomy Meeting (NAM 2008).[3]
This system is located 89 parsecs away, which is closer than most stars that are known to be orbited by Hot Jupiters.
Orbit
The planet orbits WASP-8A at an average distance of just 0.08 astronomical units (12,000,000 km) and a year passes in slightly more than 8.1 days on WASP-8b. On average, it is somewhat farther from its parent star than other Hot Jupiter planets. However, WASP-8b's orbit also has an relatively high eccentricity of 0.31, which, at periastron, brings it as close to its star as said other planets are.
One thing that stands out extremely about WASP-8b is its orbit-spin angle to its star of 123+3.4
−4.4°: This implies that the planet actually orbits retrograde to the spin of the parent star.[4][5][6]
Physical characteristics
WASP-8b has a mass about 2.2 times and a radius slightly bigger than that of the planet Jupiter. This implies that the planet is actually denser than Jupiter, unlike other Hot Jupiters.
Owing to its close distance to its star, WASP-8b is extremely hot: Its measured dayside temperature is 1,552 K (1,279 °C), this is even hotter than its equilibrium temperature of 948 K (675 °C).[2]
See also
References
- ^ Density is calculated from the mass and the radius, assuming a circular disc of eclipse relative to the Earth.
- ^ a b Patricio Cubillos et al., "The Characterization of the Cool and Eccentric Exoplanet WASP-8b with Spitzer" in DPS Annual Meeting session "103.Extrasolar Planets: Atmospheric Chemistry and Characterization" (Monday, Oct 15, 2012, 11:40 AM -11:50 AM).
- ^ "SuperWASP scoops ten exoplanets in six months". Astronomy Now. 2008-04-01.
{{cite web}}: CS1 maint: url-status (link) - ^ European Southern Observatory. "Artist's impression of an exoplanet WASP 8b in a retrograde orbit".
- ^ Didier Queloz; et al. (2010). "WASP-8b: a retrograde transiting planet in a multiple system". Astronomy and Astrophysics. 517: L1. arXiv:1006.5089. Bibcode:2010A&A...517L...1Q. doi:10.1051/0004-6361/201014768.
- ^ Obliquities of Hot Jupiter host stars: Evidence for tidal interactions and primordial misalignments, 2012, arXiv:1206.6105
External links
Media related to WASP-8b at Wikimedia Commons
