Kepler-277
Star in Lyra
From Wikipedia, the free encyclopedia
Kepler-277 is a large yellow star about 961 ± 10 parsecs (3,134 ± 33 ly) away in the constellation of Lyra. It is 1.69 R☉ and 1.12 M☉, with a temperature of 5946 K, a metallicity of -0.315 [Fe/H], and an unknown age.[3] For comparison, the Sun has a temperature of 5778 K, a metallicity of 0.00 [Fe/H], and an age of about 4.5 billion years. The large radius in comparison to its mass and temperature suggest that Kepler-277 could be a subgiant star.
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Lyra[1] |
| Right ascension | 19h 06m 19.95772s[2] |
| Declination | +39° 04′ 37.8616″[2] |
| Apparent magnitude (V) | 13.544[3] |
| Characteristics | |
| Evolutionary stage | subgiant[2] |
| Spectral type | G1V[citation needed] |
| Astrometry | |
| Radial velocity (Rv) | −62.35±1.85[2] km/s |
| Proper motion (μ) | RA: +5.818 mas/yr[2] Dec.: +17.290 mas/yr[2] |
| Parallax (π) | 1.0406±0.0106 mas[2] |
| Distance | 3,130 ± 30 ly (961 ± 10 pc) |
| Absolute magnitude (MV) | 3.39[citation needed] |
| Details[3] | |
| Mass | 1.263+0.031 −0.076[4] M☉ |
| Radius | 1.714+0.029 −0.026[4] R☉ |
| Luminosity | 3.70 L☉ |
| Temperature | 5914 K |
| Metallicity [Fe/H] | 0.100 dex |
| Age | 4.07 Gyr |
| Other designations | |
| Kepler-277, KOI-1215, KIC 3939150, 2MASS J19061996+3904379[5] | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
Planetary system
Kepler-277 hosts two exoplanets, detected in 2014 via the transit method.[3] Named Kepler-277b and Kepler-277c, they are mega-Earths, notable for their unusually high estimated masses and densities.[6] A 2025 study speculated that additional, undetected non-transiting planets may bias the transit-timing variation analysis used to estimate the planets' masses.[4]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 33.6+15.1 −8.2 M🜨 |
0.142 | 17.324161(44) | — | — | 2.92+0.73 −0.63 R🜨 |
| c | 40.4+9.4 −7.0 M🜨 |
0.218 | 33.00672(10) | — | — | 3.36+0.83 −0.72 R🜨 |