Gliese 251

Gliese 251

Gliese 251 Location of Gliese 251 in the constellation Gemini
Observation data Epoch J2000      Equinox J2000
Constellation	Gemini
Right ascension	06^h 54^m 48.95806^s[1]
Declination	+33° 16′ 05.4383″[1]
Apparent magnitude (V)	+10.11[2]
Characteristics
Spectral type	M3.0Ve[3]
U−B color index	+1.20[4]
B−V color index	+1.60[4]
Astrometry
Radial velocity (Rv)	22.30±0.19[1] km/s
Proper motion (μ)	RA: -726.672 mas/yr[1] Dec.: -398.102 mas/yr[1]
Parallax (π)	179.0629 ± 0.0280 mas[1]
Distance	18.215 ± 0.003 ly (5.5846 ± 0.0009 pc)
Absolute magnitude (MV)	11.23[5]
Details
Mass	0.360±0.015[6] M☉
Radius	0.364±0.011[6] R☉
Luminosity	0.01691±0.00028[7] L☉
Surface gravity (log g)	4.96±0.07[7] cgs
Temperature	3451±51[7] K
Metallicity [Fe/H]	-0.03±0.16[7] dex
Rotation	122.1+1.9 −2.2 d[6]
Rotational velocity (v sin i)	≤2[6] km/s
Other designations
GJ 251, HD 265866, HIP 33226, LHS 1879, LTT 11941, Wolf 294, 2MASS J06544902+3316058[8]
Database references
SIMBAD	data
ARICNS	data

Gliese 251, also known as HIP 33226 or HD 265866, is a star located 18.2 light-years away from the Solar System. Located in the constellation of Gemini, it is the nearest star in this constellation.[9]: 84  It is located near the boundary with Auriga, 49 arcminutes away from the bright star Theta Geminorum; due to its apparent magnitude of +9.89 it cannot be observed with the naked eye.[2] The closest star to Gliese 251 is QY Aurigae, which is located 3.5 light years away.[10]

Gliese 251 is a red dwarf with a spectral type of M3V[3] with an effective temperature of about 3300 K.[3] Its mass has been measured to be around 0.36 solar masses[6] and its radius is about 36% solar radii.[6] Its metallicity is likely slightly less than that of the Sun.[7] Observations at infrared wavelengths rule out the presence of a circumstellar disk around it.[11]

Planetary system

In 2019, two candidate planets were detected by the radial velocity method to orbit Gliese 251 at orbits of 1.74 and 607 days.[12] However, a new study in 2020 using CARMENES data refuted both candidates, as they found that both signals were caused by stellar activity. Based on the CARMENES data, the team announced that Gliese 251 is orbited by one single super-Earth (Gliese 251 b) at an orbit of 14.238 days.[6]

The Gliese 251 planetary system[6]

Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
b	≥4.0±0.4 M🜨	0.0818^+0.0011 −0.0012	14.238±0.002	0.10+0.09 −0.07	—	—

See also

• List of exoplanets discovered in 2020 - Gliese 251 b

References

1. 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.
2. Høg, E.; et al. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27 – L30. Bibcode:2000A&A...355L..27H.
3. Lépine, Sébastien (2013). "A Spectroscopic Catalog of the Brightest (J < 9) M Dwarfs in the Northern Sky". The Astronomical Journal. 145 (4): 102. arXiv:1206.5991. Bibcode:2013AJ....145..102L. doi:10.1088/0004-6256/145/4/102. S2CID 117144290.
4. Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode:1986EgUBV........0M. Archived from the original on 2019-12-08. Retrieved 2017-02-09.
5. "ARICNS 4C00526". ARICNS. Archived from the original on 31 August 2021. Retrieved 8 February 2017.
6. Stock, S.; et al. (2020). "The CARMENES search for exoplanets around M dwarfs. Three temperate-to-warm super-Earths" (PDF). Astronomy & Astrophysics. 643. EDP Sciences: A112. arXiv:2010.00474. Bibcode:2020A&A...643A.112S. doi:10.1051/0004-6361/202038820. ISSN 0004-6361. S2CID 222090233. Retrieved 2025-01-03.
7. Schweitzer, A.; Passegger, V. M.; Cifuentes, C.; Béjar, V. J. S.; Cortés-Contreras, M.; Caballero, J. A.; del Burgo, C.; Czesla, S.; Kürster, M.; Montes, D.; Zapatero Osorio, M. R.; Ribas, I.; Reiners, A.; Quirrenbach, A.; Amado, P. J.; Aceituno, J.; Anglada-Escudé, G.; Bauer, F. F.; Dreizler, S.; Jeffers, S. V.; Guenther, E. W.; Henning, T.; Kaminski, A.; Lafarga, M.; Marfil, E.; Morales, J. C.; Schmitt, J. H. M. M.; Seifert, W.; Solano, E.; Tabernero, H. M.; Zechmeister, M. (2019). "The CARMENES search for exoplanets around M dwarfs" (PDF). Astronomy & Astrophysics. 625. EDP Sciences: A68. arXiv:1904.03231. Bibcode:2019A&A...625A..68S. doi:10.1051/0004-6361/201834965. ISSN 0004-6361. Retrieved 2025-01-03.
8. "GJ 251". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 8 February 2017.
9. Kirkpatrick, J. Davy; Marocco, Federico; et al. (April 2024). "The Initial Mass Function Based on the Full-sky 20 pc Census of ~3600 Stars and Brown Dwarfs". The Astrophysical Journal Supplement Series. 271 (2): 55. arXiv:2312.03639. Bibcode:2024ApJS..271...55K. doi:10.3847/1538-4365/ad24e2.
10. "Stars within 15 light-years of Wolf 294". The Internet Stellar Database. Retrieved 7 February 2017.
11. Beichman, C. A.; et al. (2006). "New Debris Disks around Nearby Main-Sequence Stars: Impact on the Direct Detection of Planets". The Astrophysical Journal. 652 (2): 1674–1693. arXiv:astro-ph/0611682. Bibcode:2006ApJ...652.1674B. doi:10.1086/508449. S2CID 14207148.
12. Barnes, J. R.; et al. (2019-06-11). "Frequency of planets orbiting M dwarfs in the Solar neighbourhood". arXiv:1906.04644 [astro-ph.EP].

Notes