The HAT-P-40 system contains 1 exoplanet. It is located 1514.89 light years away from the solar system.
| Mass | 1.03 solar masses |
| Radius | 1.94 solar radiae |
| Temperature | 6080 kelvin |
| Stellar Metallicity | 0.22 decimal exponent |
| Age | 2.7 billion years |
At more than 50 Earth masses, HAT-P-40 b is a gas giant, a planet whose mass is mostly made up of hydrogen and helium, like Jupiter and Saturn.
| Mass | 152.558 Earth masses |
| Density | 0.150 grams per cubic centimeter |
| Radius | 17.038 Earth radiae |
| Semi-major Axis | 0.0608 AU |
| Eccentricity | 0 |
| Orbital Period | 4.457 days |
| Discovery Method | Transit |
| Discovery Facility | HATNet |
| Discovery Telescope | Canon 200mm f/1.8L |
| Discovery Instrument | 2K CCD Sensor |
| Discovery Date | 2012-11 |
| Reference | Hartman et al. 2012 |