Article · Wikipedia archive · Last revised Aug 4, 2026

Kepler-44

Kepler-44, formerly known as KOI-204, is a star in the northern constellation of Cygnus. With an apparent visual magnitude of 15.0 this star is too faint to be seen with the naked eye.

Last revised
Aug 4, 2026
Read time
≈ 2 min
Length
454 w
Citations
21
Source
Kepler-44
Observation data
Epoch J2000      Equinox ICRS
Constellation Cygnus1
Right ascension 20h 00m 24.5657s2
Declination +45° 45′ 43.763″2
Apparent magnitude (V) 15.03
Characteristics
Evolutionary stage subgiant2
Spectral type G0V~G0IV4
Astrometry
Proper motion (μ) RA: −0.956(18) mas/yr2
Dec.: +8.241(19) mas/yr2
Parallax (π)0.8719±0.0163 mas2
Distance3,740 ± 70 ly
(1,150 ± 20 pc)
Details
Mass1.19±0.105 M
Radius1.52±0.095 R
Luminosity2.286 L
Temperature5,757±1345 K
Metallicity [Fe/H]0.26±0.105 dex
Rotation44.68 days7
Rotational velocity (v sin i)5.5±1.55 km/s
Age6.955 Gyr
Other designations
KOI-204, KIC 9305831, 2MASS J20002456+4545437
Database references
SIMBADdata
KICdata

Kepler-44, formerly known as KOI-204, is a star in the northern constellation of Cygnus. With an apparent visual magnitude of 15.03 this star is too faint to be seen with the naked eye.

Planetary system

The Kepler spacecraft detected a transiting planet candidate around this star that was confirmed by radial velocity measurements taken by the SOPHIE spectrograph mounted on the 1.93 m telescope at the Haute-Provence Observatory.8 The planet is likely to be tidally locked to the parent star. In 2015, the planetary nightside temperature was estimated to be equal to 2347+149
−280
K.9

The Kepler-44 planetary system4
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination
(°)
Radius
b 1.02 MJ 0.0455 3.246774 13 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. Santos, N. C.; Sousa, S. G.; Mortier, A.; Neves, V.; Adibekyan, V.; Tsantaki, M.; Delgado Mena, E.; Bonfils, X.; Israelian, G.; Mayor, M.; Udry, S. (2013). "SWEET-Cat: A catalogue of parameters for Stars with ExoplanETs. I. New atmospheric parameters and masses for 48 stars with planets". Astronomy and Astrophysics. 556: A150. arXiv:1307.0354. Bibcode:2013A&A...556A.150S. doi:10.1051/0004-6361/201321286.
  4. Schneider, Jean, "Star: Kepler-44", Extrasolar Planets Encyclopaedia, retrieved 2011-12-06{{citation}}: CS1 maint: deprecated archival service (link)
  5. Kepler-44b, NASA Ames Research Center, archived from the original on 2015-09-14, retrieved 2011-12-06
  6. Ulmer-Moll, S.; Santos, N. C.; Figueira, P.; Brinchmann, J.; Faria, J. P. (2019). "Beyond the exoplanet mass-radius relation". Astronomy and Astrophysics. 630: A135. arXiv:1909.07392. Bibcode:2019A&A...630A.135U. doi:10.1051/0004-6361/201936049.
  7. Mazeh, Tsevi; Perets, Hagai B.; McQuillan, Amy; Goldstein, Eyal S. (2015). "Photometric Amplitude Distribution of Stellar Rotation of KOIs—Indication for Spin-Orbit Alignment of Cool Stars and High Obliquity for Hot Stars". The Astrophysical Journal. 801 (1): 3. arXiv:1501.01288. Bibcode:2015ApJ...801....3M. doi:10.1088/0004-637X/801/1/3.
  8. Bonomo, A. S.; et al. (2012). "SOPHIE velocimetry of Kepler transit candidates. V. The three hot Jupiters KOI-135b, KOI-204b, and KOI-203b (alias Kepler-17b)". Astronomy and Astrophysics. 538. A96. arXiv:1110.5462. Bibcode:2012A&A...538A..96B. doi:10.1051/0004-6361/201118323. S2CID 118528032.
  9. A Comprehensive Study of Kepler Phase Curves and Secondary Eclipses:Temperatures and Albedos of Confirmed Kepler Giant Planets