Article · Wikipedia archive · Last revised Jun 13, 2026

Kepler-445

Kepler-445 is a red dwarf star located 401 light-years away in the constellation Cygnus. It hosts three known exoplanets, discovered by the transit method using data from the Kepler space telescope and confirmed in 2015. None of the planets orbit within the habitable zone.

Last revised
Jun 13, 2026
Read time
≈ 2 min
Length
511 w
Citations
27
Source
Kepler-445
Observation data
Epoch J2000      Equinox J2000
Constellation Cygnus1
Right ascension 19h 54m 56.65923s2
Declination +46° 29′ 54.7936″2
Apparent magnitude (V) 18.193
Characteristics
Evolutionary stage Main sequence42
Spectral type M4V5
Apparent magnitude (G) 16.685±0.0032
Apparent magnitude (J) 13.542±0.0296
Apparent magnitude (H) 12.929±0.0356
Apparent magnitude (K) 12.610±0.0286
Astrometry
Proper motion (μ) RA: 41.465 mas/yr2
Dec.: 132.351 mas/yr2
Parallax (π)8.1366±0.0457 mas2
Distance401 ± 2 ly
(122.9 ± 0.7 pc)
Details4
Mass0.334+0.080
−0.059
 M
Radius0.347+0.068
−0.049
 R
Luminosity (bolometric)0.0115 L
Temperature3219+89
−63
 K
Metallicity [Fe/H]+0.27 dex
Other designations
Kepler-445, KOI-2704, KIC 9730163, TIC 268060194, 2MASS J19545665+46295486
Database references
SIMBADdata
Exoplanet Archivedata

Kepler-445 is a red dwarf star located 401 light-years (123 parsecs) away in the constellation Cygnus. It hosts three known exoplanets, discovered by the transit method using data from the Kepler space telescope and confirmed in 2015.7 None of the planets orbit within the habitable zone.8

Planetary system

Kepler-445b, c, and d orbit Kepler-445 every 3, 5, and 8 days,3 and have equilibrium temperatures of 401 K (128 °C; 262 °F), 341 K (68 °C; 154 °F), and 305 K (32 °C; 89 °F), respectively.9 With a radius of 2.72 times that of Earth, Kepler-445c is likely a mini-Neptune with a volatile-rich composition, and has been compared to GJ 1214 b.7 Kepler-445d is only slightly larger than the Earth, with a radius of 1.33 R🜨.

The Kepler-445 planetary system4
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination
(°)
Radius
b 0.023656 2.98416640+0.00000891
−0.00000936
0.02+0.16
−0.02
89.74+0.18
−0.28
7
1.74+0.29
−0.28
 R🜨
c 0.033427 4.87122714+0.00000636
−0.00000638
0.01+0.16
−0.01
89.91+0.07
−0.10
7
2.72+0.44
−0.43
 R🜨
d 0.047121 8.15272856+0.00006453
−0.00007041
0.01+0.16
−0.01
89.61+0.27
−0.25
7
1.33+0.25
−0.23
 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. "Kepler-445". NASA Exoplanet Archive. Retrieved 24 May 2023.
  4. Mann, Andrew W.; Dupuy, Trent; Muirhead, Philip S.; Johnson, Marshall C.; Liu, Michael C.; Ansdell, Megan; Dalba, Paul A.; Swift, Jonathan J.; Hadden, Sam (2017). "The Gold Standard: Accurate Stellar and Planetary Parameters for Eight Kepler M Dwarf Systems Enabled by Parallaxes". The Astronomical Journal. 153 (6): 267. arXiv:1705.01545. Bibcode:2017AJ....153..267M. doi:10.3847/1538-3881/aa7140. S2CID 119325474.
  5. Muirhead, Philip S.; Becker, Juliette; Feiden, Gregory A.; Rojas-Ayala, Bárbara; Vanderburg, Andrew; Price, Ellen M.; Thorp, Rachel; Law, Nicholas M.; Riddle, Reed; Baranec, Christoph; Hamren, Katherine; Schlawin, Everett; Covey, Kevin R.; Johnson, John Asher; Lloyd, James P. (2014). "Characterizing the Cool KOIs. VI. H- and K-band Spectra of Kepler M Dwarf Planet-candidate Hosts". The Astrophysical Journal Supplement Series. 213 (1): 5. arXiv:1406.2718. Bibcode:2014ApJS..213....5M. doi:10.1088/0067-0049/213/1/5.
  6. "Kepler-445". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 24 May 2023.
  7. Muirhead, Philip S.; Mann, Andrew W.; et al. (March 2015). "Kepler-445, Kepler-446 and the Occurrence of Compact Multiples Orbiting Mid-M Dwarf Stars". The Astrophysical Journal. 801 (1): 18. arXiv:1501.01305. Bibcode:2015ApJ...801...18M. doi:10.1088/0004-637X/801/1/18. S2CID 5541362.
  8. "[...] all of the planets are likely too hot to be located within their host stars’ habitable zones [...]"7: 8 
  9. "Kepler Objects of Interest".