Gliese 208

Gliese 208 (Gj 208) is a red dwarf star with an apparent magnitude of 8.9. It is 37 light years away in the constellation of Orion. It is an extremely wide binary with 2MASS J0536+1117, an M4 star 2.6 arcminutes away (at least 0.028 light years)

Gliese 208

A visual band light curve for V2689 Orionis, adapted from Kiraga (2012)[1]
Observation data Epoch J2000      Equinox J2000
Constellation	Orion
Right ascension	05h 36m 30.991s[2]
Declination	+11° 19′ 40.33″[2]
Apparent magnitude (V)	8.80 - 9.05[3]
Characteristics
Spectral type	M0.0 Ve[4]
Variable type	RS CVn[3]
Astrometry
Radial velocity (Rv)	21.772[5] km/s
Proper motion (μ)	RA: −2.811 ± 0.080[2] mas/yr Dec.: −56.368 ± 0.060[2] mas/yr
Parallax (π)	87.66 ± 0.29 mas[2]
Distance	37.2 ± 0.1 ly (11.41 ± 0.04 pc)
Absolute magnitude (MV)	8.6
Details
Mass	0.646[6] M☉
Radius	0.601[6] R☉
Luminosity	0.08[7] L☉
Temperature	3,966[6] K
Metallicity [Fe/H]	+0.05[6] dex
Age	2.7[6] Gyr
Other designations
Gliese 208, Gj 208, V2689 Orionis, BD+11°878, HIP 26335, HD 245409, TYC 709-63-1, SAO 94695
Database references
SIMBAD	data

The spectral type of Gj 208 has variously been described between K6 and M1.^[8][9][10] Two of the most recent observations give a statistically calculated spectral type of K7.9^[6] or a more traditional classification of M0.0 Ve.^[4] It is a cool dwarf star and probably a spectroscopic binary.^[3]

Calculations from 2010 suggest that this star passed as close as 1.537 parsecs (5.0 light-years) from the Sun about 500,000 years ago.^[11]

GJ 208 is an RS Canum Venaticorum variable, close binary systems which show small amplitude brightness changes caused by chromospheric activity. Its visual magnitude varies by about a quarter magnitude with a period of 12.285 days.^[3]

References

1. Kiraga, M. (March 2012). "ASAS Photometry of ROSAT Sources. I. Periodic Variable Stars Coincident with Bright Sources from the ROSAT All Sky Survey". Acta Astronomica. 62 (1): 67–95. arXiv:1204.3825. Bibcode:2012AcA....62...67K. Archived from the original on 4 March 2023. Retrieved 10 February 2022.
2. Gaia Collaboration (2016). "VizieR Online Data Catalog: Gaia DR1 (Gaia Collaboration, 2016)". VizieR On-line Data Catalog: I/337. Originally Published in: Astron. Astrophys. 1337. Bibcode:2016yCat.1337....0G. doi:10.26093/cds/vizier.1337.
3. Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.
4. Lépine, Sébastien; Hilton, Eric J.; Mann, Andrew W.; Wilde, Matthew; Rojas-Ayala, Bárbara; Cruz, Kelle L.; Gaidos, Eric (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.
5. Soubiran, C.; Jasniewicz, G.; Chemin, L.; Crifo, F.; Udry, S.; Hestroffer, D.; Katz, D. (2013). "The catalogue of radial velocity standard stars for Gaia. I. Pre-launch release". Astronomy & Astrophysics. 552: A64. arXiv:1302.1905. Bibcode:2013A&A...552A..64S. doi:10.1051/0004-6361/201220927. S2CID 56094559.
6. Mann, Andrew W.; Feiden, Gregory A.; Gaidos, Eric; Boyajian, Tabetha; von Braun, Kaspar (2015). "How to Constrain Your M Dwarf: Measuring Effective Temperature, Bolometric Luminosity, Mass, and Radius". The Astrophysical Journal. 804 (1): 64. arXiv:1501.01635. Bibcode:2015ApJ...804...64M. doi:10.1088/0004-637X/804/1/64. S2CID 19269312.
7. McDonald, I.; Zijlstra, A. A.; Boyer, M. L. (2012). "Fundamental parameters and infrared excesses of Hipparcos stars". Monthly Notices of the Royal Astronomical Society. 427 (1): 343–357. arXiv:1208.2037. Bibcode:2012MNRAS.427..343M. doi:10.1111/j.1365-2966.2012.21873.x. S2CID 118665352.
8. Stephenson, C. B. (1986). "Dwarf K and M stars of high proper motion found in a hemispheric survey". Astronomical Journal. 92: 139. Bibcode:1986AJ.....92..139S. doi:10.1086/114146.
9. Stephenson, C. B.; Sanduleak, N. (1975). "Dwarf K and M stars discovered on objective-prism plates". Astronomical Journal. 80: 972. Bibcode:1975AJ.....80..972S. doi:10.1086/111829.
10. Skiff, B. A. (2014). "VizieR Online Data Catalog: Catalogue of Stellar Spectral Classifications (Skiff, 2009-2016)". VizieR On-line Data Catalog: B/Mk. Originally Published in: Lowell Observatory (October 2014). 1. Bibcode:2014yCat....1.2023S.
11. Bobylev, Vadim V. (March 2010). "Searching for Stars Closely Encountering with the Solar System". Astronomy Letters. 36 (3): 220–226. arXiv:1003.2160. Bibcode:2010AstL...36..220B. doi:10.1134/S1063773710030060. S2CID 118374161.

External links

• Wikisky image Archived 2012-10-11 at the Wayback Machine of HD 245409 (Gliese 208)