Article · Wikipedia archive · Last revised Jun 26, 2026

Kepler-32

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, 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.

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Kepler-32
Observation data
Epoch J2000      Equinox J2000
Constellation Cygnus1
Right ascension 19h 51m 22.1744s2
Declination +46° 34′ 27.391″2
Apparent magnitude (V) 16.03
Characteristics
Evolutionary stage main sequence4
Spectral type M1V5
Astrometry
Proper motion (μ) RA: −13.762(31) mas/yr2
Dec.: 19.586(32) mas/yr2
Parallax (π)3.0960±0.0276 mas2
Distance1,053 ± 9 ly
(323 ± 3 pc)
Details
Mass0.58±0.053 M☉
Radius0.53±0.043 R☉
Surface gravity (log g)4.645 cgs
Temperature3900±2003 K
Metallicity [Fe/H]0.00 dex
Rotation36.220±0.256 days6
Other designations
KIC 9787239, KOI-952, 2MASS J19512217+4634273, Gaia DR2 20802878925253598725
Database references
SIMBADdata
Exoplanet Archivedata
KICdata

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

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

The Kepler-32 planetary system15
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 0.01116 MJ 0.05 5.90124 — — 2.2±0.2 R🜨
c 0.01216 MJ 0.09 8.7522 — — 2.0±0.2 R🜨
d — 0.129 22.780806 — — 2.7±0.1 R🜨
References

References

  1. Roman, Nancy G. (1987). "Identification of a constellation from a position". Publications of the Astronomical Society of the Pacific. 99 (617): 695. Bibcode:1987PASP...99..695R. doi:10.1086/132034. Constellation record for this object at VizieR.
  2. Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
  3. "Notes on Kepler-32 b". Extrasolar Planets Encyclopaedia. Retrieved 21 January 2017.
  4. Wanderley, Fábio; Cunha, Katia; Smith, Verne V.; Souto, Diogo; Pascucci, I.; Behmard, Aida; Allende Prieto, C.; Beaton, Rachael L.; Bizyaev, D.; Daflon, S.; Hasselquist, S.; Howell, Steve; Majewski, Steven R.; Pinsonneault, Marc (2025). "An Analysis of the Radius Gap in a Sample of Kepler, K2, and TESS Exoplanets Orbiting M-dwarf Stars". The Astrophysical Journal. 993 (2): 233. arXiv:2509.01930. Bibcode:2025ApJ...993..233W. doi:10.3847/1538-4357/ae058e.
  5. "KOI-952". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 21 January 2017.
  6. McQuillan, A.; Mazeh, T.; Aigrain, S. (2013). "Stellar Rotation Periods of The Kepler objects of Interest: A Dearth of Close-In Planets Around Fast Rotators". The Astrophysical Journal Letters. 775 (1). L11. arXiv:1308.1845. Bibcode:2013ApJ...775L..11M. doi:10.1088/2041-8205/775/1/L11. S2CID 118557681.
  7. NBC (3 January 2013). "100 billion alien planets fill our galaxy: study". NBC News. Retrieved 28 February 2013.
  8. Swift, Jonathan J. (2012). "Characterizing the Cool KOIs IV: Kepler-32 as a prototype for the formation of compact planetary systems throughout the Galaxy". The Astrophysical Journal. 764 (1): 105. arXiv:1301.0023. Bibcode:2013ApJ...764..105S. doi:10.1088/0004-637X/764/1/105. S2CID 43750666.
  9. Lissauer, Jack J.; Ragozzine, Darin; Fabrycky, Daniel C.; Steffen, Jason H.; Ford, Eric B.; Jenkins, Jon M.; Shporer, Avi; Holman, Matthew J.; Rowe, Jason F.; Quintana, Elisa V.; Batalha, Natalie M.; Borucki, William J.; Bryson, Stephen T.; Caldwell, Douglas A.; Carter, Joshua A.; Ciardi, David; Dunham, Edward W.; Fortney, Jonathan J.; Gautier, Iii, Thomas N.; Howell, Steve B.; Koch, David G.; Latham, David W.; Marcy, Geoffrey W.; Morehead, Robert C.; Sasselov, Dimitar (2011), "Architecture and Dynamics of Kepler 'S Candidate Multiple Transiting Planet Systems", The Astrophysical Journal Supplement Series, 197 (1): 8, arXiv:1102.0543, Bibcode:2011ApJS..197....8L, doi:10.1088/0067-0049/197/1/8, S2CID 43095783
  10. The Extrasolar Planet Encyclopedia. "Kepler-32". Exoplanet.eu. Archived from the original on 3 February 2014. Retrieved 28 February 2013.
  11. Fabrycky, Daniel C.; et al. (2012). "Transit Timing Observations from Kepler: IV. Confirmation of 4 Multiple Planet Systems by Simple Physical Models". The Astrophysical Journal. 750 (2): 114. arXiv:1201.5415. Bibcode:2012ApJ...750..114F. doi:10.1088/0004-637X/750/2/114. S2CID 9075167.
  12. T. O. Hands, R. D. Alexander, W. Dehnen, "Understanding the assembly of Kepler's compact planetary systems", 2014
  13. Hands, T. O.; Alexander, R. D. (2015), "There might be giants: unseen Jupiter-mass planets as sculptors of tightly-packed planetary systems", Monthly Notices of the Royal Astronomical Society, 456 (4): 4121–4127, arXiv:1512.02649, Bibcode:2016MNRAS.456.4121H, doi:10.1093/mnras/stv2897, S2CID 55175754
  14. Becker, Juliette C.; Adams, Fred C. (2017), "Effects of Unseen Additional Planetary Perturbers on Compact Extrasolar Planetary Systems", Monthly Notices of the Royal Astronomical Society, 468 (1): 549–563, arXiv:1702.07714, Bibcode:2017MNRAS.468..549B, doi:10.1093/mnras/stx461, S2CID 119325005
  15. NASA Exoplanet Archive--Planet Host Overview page:Kepler-32
  16. Characterizing the Cool KOIs. IV. Kepler-32 as a Prototype for the Formation of Compact Planetary Systems throughout the Galaxy