HD 149026 b
Size comparison of Smertrios with Neptune and Jupiter | |
| Discovery | |
|---|---|
| Discovered by | B. Sato, D. Fischer, G. Henry et al. |
| Discovery site | W. M. Keck Observatory |
| Discovery date | 1 July 2005 |
| Radial velocity | |
| Orbital characteristics | |
| 0.04364 ± 0.00022 AU (6,528,000 ± 33,000 km) | |
| Eccentricity | <0.013 |
| 2.87588874 ± 5.9×10−7 d | |
| Inclination | 84.50°+0.60° −0.52° |
| Semi-amplitude | 37.9+1.8 −1.3 m/s |
| Star | HD 149026 |
| Physical characteristics | |
| 0.811+0.029 −0.027 RJ | |
| Mass | 0.322+0.014 −0.012 MJ |
Mean density | 0.750+0.089 −0.077 g/cm3 |
| Albedo | 0.53+0.09 −0.11 (Bond) |
| Temperature | 1,804±98 K (1,531 °C; 2,788 °F, dayside) 1,032±120 K (759 °C; 1,398 °F, nightside) |
HD 149026 b, formally named Smertrios /ˈsmɜːrtriɒs/, is an exoplanet, specifically a hot Jupiter, approximately 250 light-years from the Sun in the constellation of Hercules. Its host star is HD 149026, also named Ogma /ˈɒɡmə/.
The planet orbits the yellow subgiant star HD 149026 with a 2.8766-day period at a distance of 0.042 AU (3.9 million mi; 6.3 million km), and is notable first as a transiting planet, and second for a small measured radius (relative to mass and incoming heat) that suggests an exceptionally large planetary core.