Kepler-23
Star in the constellation Cygnus
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Kepler-23 is a G-type main-sequence star about 2,860 light-years (880 parsecs) away in the northern constellation of Cygnus, the swan. With an apparent visual magnitude of 13.5,[3] it is too faint to be seen with the naked eye. This star is similar in mass and temperature to the Sun, but is larger and more luminous.[5][4] Kepler-23 is orbited by three known exoplanets.[6]
Kepler-23 compared to the Sun | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cygnus[1] |
| Right ascension | 19h 36m 52.5355s[2] |
| Declination | +49° 28′ 45.253″[2] |
| Apparent magnitude (V) | 13.547[3] |
| Characteristics | |
| Evolutionary stage | subgiant[2] |
| Spectral type | G2V[3] |
| Astrometry | |
| Radial velocity (Rv) | −26.97±2.38[2] km/s |
| Proper motion (μ) | RA: 2.275(12) mas/yr[2] Dec.: 3.879(14) mas/yr[2] |
| Parallax (π) | 1.1395±0.0101 mas[2] |
| Distance | 2,860 ± 30 ly (878 ± 8 pc) |
| Details | |
| Mass | 1.078±0.077[4] M☉ |
| Radius | 1.548±0.048[4] R☉ |
| Luminosity | ~2.3[5] L☉ |
| Surface gravity (log g) | 4.00±0.14[5] cgs |
| Temperature | 5828±100[4] K |
| Metallicity [Fe/H] | −0.09±0.14[5] dex |
| Age | 4-8[5] Gyr |
| Other designations | |
| KOI-168, KIC 11512246, GSC 03564-01806, 2MASS J19365254+4928452, Gaia DR2 2135019107451751168[3] | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
| KIC | data |
Planetary system
Three transiting exoplanets orbit this star, discovered using the Kepler space telescope. Two planets, Kepler-23b and Kepler-23c, were discovered in 2011 and were confirmed in 2012.[5] A third planet, Kepler-23d, was confirmed in 2014 as part of a study validating hundreds of Kepler candidates.[7] All three planets are between Earth and Neptune in size (sub-Neptunes), and their masses have been measured via transit-timing variations, showing that they have lower densities than Earth.[4]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 2.56+0.43 −0.40 M🜨 |
0.075 | 7.106995(73) | 0.017+0.019 −0.014 |
— | 1.638±0.047 R🜨 |
| c | 7.81+1.32 −1.20 M🜨 |
0.099 | 10.742434(39) | 0.021+0.009 −0.014 |
— | 3.005±0.074 R🜨 |
| d | 4.44+1.30 −1.21 M🜨 |
0.124 | 15.27429(17) | 0.010+0.014 −0.008 |
— | 2.206±0.057 R🜨 |
