| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 19h 36m 05.5270s |
| Declination | +45° 51′ 11.108″ |
| Apparent magnitude (V) | 14.0 |
| Characteristics | |
| Evolutionary stage | main sequence |
| Spectral type | G5 |
| Astrometry | |
| Proper motion (μ) | RA: −1.007(25) mas/yr Dec.: −7.439(23) mas/yr |
| Parallax (π) | 0.6013±0.0200 mas |
| Distance | 5,400 ± 200 ly (1,660 ± 60 pc) |
| Details | |
| Mass | 1.21±0.17 M☉ |
| Radius | 1.22±0.24 R☉ |
| Luminosity | 0.79±0.04 L☉ |
| Temperature | 6,340±200 K |
| Metallicity [Fe/H] | −0.076±0.400 dex |
| Other designations | |
| KOI-935, KIC 9347899, 2MASS J19360552+4551110, Gaia DR2 2128013019361703936 | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
| KIC | data |
Kepler-31 is a star in the northern constellation of Cygnus, the swan. It is orbited by three known exoplanets. It is located at the celestial coordinates: Right Ascension 19h 36m 05.5270s, Declination +45° 51′ 11.108″. With an apparent visual magnitude of 14.0, this star is too faint to be seen with the naked eye.
The three gas giant planets orbiting Kepler-31 were discovered in early 2011, albeit with large false alarm probability, and were confirmed in 2012. The planets form a resonant chain, with orbital periods ratio 1:2:4, although 20% probability exists that these period ratios may be coincidental.
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination (°) |
Radius |
|---|---|---|---|---|---|---|
| .04(unconfirmed) | — | 0.0937 | 9.61730282±3.35e-5 | — | — | 0.173 RJ |
| b | <6.8 MJ | 0.16 | 20.8613 | — | — | 0.38±0.07 RJ |
| c | <4.7 MJ | 0.26 | 42.6318 | — | — | 0.38±0.07 RJ |
| d | — | 0.39 | 87.648901±0.000801 | — | — | 0.407±0.099 RJ |