G 9-40 b
| Discovery | |
|---|---|
| Discovery date | December 2019 |
| radial velocity and transit | |
| Designations | |
| K2-313 b | |
| Orbital characteristics | |
| 0.04180±0.00064 AU | |
| Eccentricity | 0 |
| 5.7459982(20) d | |
| Inclination | 89.03°±0.10° |
| Physical characteristics | |
| 1.900±0.065 R🜨 | |
| Mass | 4.00±0.63 M🜨 |
Mean density | 3.20+0.63 −0.58 g/cm3 |
| 10.8±1.8 m/s2 | |
| Temperature | 440.6±7.6 K (167.5 °C; 333.4 °F, equilibrium) |
G 9-40 b is a sub-Neptune exoplanet that has an orbital period of 5.7 days. The host star is a red dwarf located 91 light-years (28 parsecs) away from Earth in the constellation Cancer. The planet was discovered in 2019. The planet's density is too low for a rocky composition, suggesting that it is either water-rich or has a significant hydrogen atmosphere.