 Size comparison of XO-2 b (gray) with Jupiter. | |
| Discovery | |
|---|---|
| Discovered by | Burke et al. |
| Discovery date | 2007 |
| Detection method | Transit (including secondary eclipse) |
| Orbital characteristics | |
| Semi-major axis | 0.0369 ± 0.002 AU (5,520,000 ± 300,000 km) |
| Eccentricity | 0 |
| Orbital period (sidereal) | 2.61586178 ± 0.00000075 d |
| Inclination | 87.62 ± 0.51 |
| Time of periastron | 2454147.74902 ± 0.00002 |
| Argument of periastron | ? |
| Semi-amplitude | 80.2 |
| Star | XO-2N (XO-2B) |
| Physical characteristics | |
| Mean radius | 0.973 ± 0.03 RJ |
| Mass | 0.57 ± 0.06 MJ |
| Mean density | 0.82 g/cm |
| Surface gravity | 1.42 m/s (0.145 g0) |
| Temperature | 1,208 K (935 °C) |
XO-2Nb (or rarely XO-2Bb) is an extrasolar planet orbiting the star XO-2N, the fainter component of XO-2 wide binary star in the constellation Lynx. This planet was found by the transit method in 2007 by Burke et al. This was the second such planet found by the XO telescope.
Like most planets found by the transit method, it is a roughly Jupiter sized planet that orbits very close to its host star; in this case, it has a surface temperature of about 1200 K, so it belongs to a group of exoplanets known as hot Jupiters. The planet takes 2.6 days to orbit the star at the average distance of 0.0369 AU. The planet has mass of 57% of Jupiter and radius of 97% of Jupiter. The radius is relatively large for its mass, probably due to its intense heating from its nearby star that bloats the planet's atmosphere. The large radius for its mass gives a low density of 820 kg/m.
See also
References
- ^ Sing, D. K.; et al. (2011). "Gran Telescopio Canarias OSIRIS transiting exoplanet atmospheric survey: detection of potassium in XO-2b from narrowband spectrophotometry". Astronomy and Astrophysics. 527. article number A73. arXiv:1008.4795. Bibcode:2011A&A...527A..73S. doi:10.1051/0004-6361/201015579. S2CID 56545385.
- "XO-2b". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2009-04-26.
- Burke, Christopher J.; et al. (2007). "XO-2b: Transiting Hot Jupiter in a Metal-rich Common Proper Motion Binary". The Astrophysical Journal. 671 (2): 2115–2128. arXiv:0705.0003. Bibcode:2007ApJ...671.2115B. doi:10.1086/523087. S2CID 13468914.
External links
Media related to XO-2b at Wikimedia Commons