Kepler-32
M-type main sequence star in the constellation Cygnus
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Kepler-32 is an M-type main sequence star located about 1053 light years from Earth, in the constellation of Cygnus. Discovered in January 2012 by the Kepler spacecraft,[7] it shows a 0.58 ± 0.05 solar mass (M☉), a 0.53 ± 0.04 solar radius (R☉), and temperature of 3900.0 K, making it half the mass and radius of the Sun, two-thirds its temperature and 5% its luminosity.[8]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cygnus[1] |
| Right ascension | 19h 51m 22.1744s[2] |
| Declination | +46° 34′ 27.391″[2] |
| Apparent magnitude (V) | 16.0[3] |
| Characteristics | |
| Evolutionary stage | main sequence[4] |
| Spectral type | M1V[5] |
| Astrometry | |
| Proper motion (μ) | RA: −13.762(31) mas/yr[2] Dec.: 19.586(32) mas/yr[2] |
| Parallax (π) | 3.0960±0.0276 mas[2] |
| Distance | 1,053 ± 9 ly (323 ± 3 pc) |
| Details | |
| Mass | 0.58±0.05[3] M☉ |
| Radius | 0.53±0.04[3] R☉ |
| Surface gravity (log g) | 4.64[5] cgs |
| Temperature | 3900±200[3] K |
| Metallicity [Fe/H] | 0.00 dex |
| Rotation | 36.220±0.256 days[6] |
| Other designations | |
| KIC 9787239, KOI-952, 2MASS J19512217+4634273, Gaia DR2 2080287892525359872[5] | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
| KIC | data |
Planetary system
In 2011, 2 planets orbiting around it, were discovered, and two more suspected.[9] The smaller Kepler-32b, orbiting its parent star every 5.90124 days, and Kepler-32c with an orbital period of 8.7522 days.[10] In April 2013, transit-timing variation analysis confirmed 3 other planets to be in the system. However, only very loose constraints of the maximum mass of the planets could be determined.[11] In 2014, the dynamical simulation shown what the Kepler-32 planetary system have likely undergone a substantial inward migration in the past, producing an observed pattern of lower-mass planets on tightest orbits.[12] Additional yet unobserved gas giant planets on wider orbit are likely necessary for migration of smaller planets to proceed that far inward,[13] although current planetary systems would be unstable if additional planets are located closer than 8.7 AU from the parent star.[14]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| f | — | 0.013 | 0.742956 | — | — | 0.81±0.05 R🜨 |
| e | — | 0.033 | 2.896009 | — | — | 1.5±0.1 R🜨 |
| b | 0.011[16] MJ | 0.05 | 5.90124 | — | — | 2.2±0.2 R🜨 |
| c | 0.012[16] MJ | 0.09 | 8.7522 | — | — | 2.0±0.2 R🜨 |
| d | — | 0.129 | 22.780806 | — | — | 2.7±0.1 R🜨 |