Gliese 436 b
Gliese 436 b /ˈɡliːzə/ (sometimes called GJ 436 b, formally named Awohali) is a Neptune-sized exoplanet orbiting the red dwarf Gliese 436. It was the first hot Neptune discovered with certainty (in 2007) and was among the smallest-known transiting planets in mass and radius, until the much smaller Kepler exoplanet discoveries began circa 2010.
Size comparison of Awohali with Neptune | |
| Discovery | |
|---|---|
| Discovered by | Butler, Vogt, Marcy et al. |
| Discovery site | California, USA |
| Discovery date | August 31, 2004 |
Detection method | Radial velocity, Transit |
| Designations | |
Alternative names | Awohali |
| Orbital characteristics | |
Semi-major axis | 0.028±0.01 AU |
| Eccentricity | 0.152+0.009 −0.008 |
Orbital period (sidereal) | 2.643904±0.000005 d |
| Inclination | 85.8+0.21 −0.25 |
| 2451552.077 | |
| 325.8+5.5 −5.7 | |
| Semi-amplitude | 17.38±0.17 |
| Star | Noquisi |
| Physical characteristics | |
Mean radius | 4.327 ± 0.183 R🜨 |
| Mass | 21.36+0.20 −0.21 ME |
Mean density | 1.51 g/cm3 (0.055 lb/cu in) |
Surface gravity | 1.18 g |
| Temperature | 712 K (439 °C; 822 °F) |
In December 2013, NASA reported that clouds may have been detected in the atmosphere of GJ 436 b.
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