Kepler-27
G-type star in the constellation Cygnus
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Kepler-27 is a star in the northern constellation of Cygnus, the swan. It is located at the celestial coordinates: Right Ascension 19h 28m 56.81962s, Declination +41° 05′ 09.1405″.[2] With an apparent visual magnitude of 15.855,[3] this star is too faint to be seen with the naked eye. In 2024, Kepler-27 was discovered to be a binary star with a red dwarf companion 1.975 arcseconds away.[10]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cygnus[1] |
| Right ascension | 19h 28m 56.81962s[2] |
| Declination | +41° 05′ 09.1405″[2] |
| Apparent magnitude (V) | 15.855[3] |
| Characteristics | |
| Evolutionary stage | subgiant[2] |
| Spectral type | K2 III-IV[4] |
| Astrometry | |
| Proper motion (μ) | RA: 2.171±0.033 mas/yr[2] Dec.: −0.324±0.031 mas/yr[2] |
| Parallax (π) | 0.9298±0.0281 mas[2] |
| Distance | 3,500 ± 100 ly (1,080 ± 30 pc) |
| Details | |
| Mass | 0.9+0.03 −0.10[5] M☉ |
| Radius | 0.850+0.017 −0.016[6] R☉ |
| Luminosity | 0.45[7] L☉ |
| Surface gravity (log g) | 4.58[7] cgs |
| Temperature | 5,249+68 −56[6] K |
| Metallicity [Fe/H] | 0.250+0.064 −0.061[6] dex |
| Rotation | 14.7 days[8] |
| Rotational velocity (v sin i) | 0.6±5.0[9] km/s |
| Age | 1.620+0.978 −0.466[6] Gyr |
| Other designations | |
| KOI-841, KIC 5792202, 2MASS J19285682+4105091, Gaia DR2 2053586321364864640 | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
| KIC | data |
Planetary system
The planetary system of Kepler-27 comprising two small gas giants on eccentric orbits[5] was discovered in late 2011.[9] The planets Kepler-27b and Kepler-27c have equilibrium temperatures of 610 K and 481 K, respectively.[11] In 2021, a third, sub-Neptune-sized planet was confirmed, orbiting closer in than the other two planets.[12][13]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| d | — | 0.070 [a] | 6.54629 | — | — | 0.2414 RJ |
| b | 0.1320±0.018 MJ | 0.118 | 15.3348 | — | — | 0.522±0.024 RJ |
| c | 0.0670±0.011 MJ | 0.191 | 31.3309 | — | — | 0.640±0.029 RJ |
Notes
- Derived from known mass of star and orbital period of planet.