HD 40307 b
| Discovery | |
|---|---|
| Discovered by | Mayor et al. |
| Discovery site | La Silla Observatory, Chile |
| Discovery date | 18 June 2008 |
| radial velocity, using HARPS | |
| Orbital characteristics | |
| 0.0468+0.0492 −0.0445 AU | |
| Eccentricity | 0.20+0.25 −0.04 |
| 4.3115 ± 0.0006 d | |
| Semi-amplitude | 1.94+2.25 −1.67 |
| Star | HD 40307 |
HD 40307 b is an extrasolar planet orbiting the star HD 40307, located 42 light-years away in the direction of the southern constellation Pictor. The planet was discovered by the radial velocity method, using the European Southern Observatory's HARPS apparatus, in June 2008. It is the second smallest of the planets orbiting the star, after HD 40307 e. The planet is of interest as this star has relatively low metallicity, supporting a hypothesis that different metallicities in protostars determine what kind of planets they will form.