| HD 69830 b | |
| Discoverer: | C. Lovis et al. |
| Discovered: | May 18, 2006 |
| Apsis: | astron |
| Semimajor: | 0.0764± |
| Time Periastron: | 2,453,496.8 ± 0.06 |
| Arg Peri: | 340 ± 26 |
HD 69830 b is a Neptune-mass or super-Earth-mass exoplanet orbiting the star HD 69830. It is at least 10 times more massive than Earth. It also orbits very close to its parent star and takes 82/3 days to complete an orbit.
Based on theoretical modeling in the 2006 discovery paper, this is likely to be a rocky planet, not a gas giant. However, other work has found that if it had formed as a gas giant, it would have stayed that way,[1] and it is now understood that planets this massive are rarely rocky.[2]
If HD 69830 b is a terrestrial planet, models predict that tidal heating would produce a heat flux at the surface of about 55 W/m2. This is 20 times that of Io.[3]