| Extrasolar planet | List of extrasolar planets | |
|---|---|---|
| Parent star | ||
| Star | XO-2 | |
| Constellation | Lynx | |
| Right ascension | (α) | 07h 48m 06.46s[1] |
| Declination | (δ) | +50° 13′ 32.9″[1] |
| Distance | 486 ± 13 ly (149 ± 4 pc) |
|
| Spectral type | K0V | |
| Orbital elements | ||
| Semimajor axis | (a) | 0.0369 ± 0.002 AU |
| Eccentricity | (e) | 0 |
| Orbital period | (P) | 2.615838 ± 0.000006 d |
| Inclination | (i) | >88.58° |
| Argument of periastron |
(ω) | ?° |
| Time of periastron | (T0) | 2454147.74902 ± 0.00002 JD |
| Semi-amplitude | (K) | 80.2 m/s |
| Physical characteristics | ||
| Mass | (m) | 0.57 ± 0.06 MJ |
| Radius | (r) | 0.973 ± 0.03 RJ |
| Density | (ρ) | 820 kg m-3 |
| Surface gravity | (g) | 1.42 m/s² |
| Temperature | (T) | 1208 K |
| Discovery information | ||
| Discovery date | 2007 | |
| Discoverer(s) | Burke et al. | |
| Detection method | Transit | |
| Discovery status | Published | |
| Database references | ||
| Extrasolar Planets Encyclopaedia |
data | |
| SIMBAD | data | |
XO-2b is an extrasolar planet orbiting the star XO-2 in the constellation Lynx.[1] This planet was found by 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/m3.[2]
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