Gliese 908

Gliese 908 is a red dwarf star, located in constellation Pisces at 19.3 light-years from Earth. It is a BY Draconis variable star with a variable star designation of BR Piscium. Its apparent magnitude varies between magnitude 8.93 and magnitude 9.03 as a result of starspots and varying chromospheric activity.

Gliese 908

Observation data Epoch J2000      Equinox J2000
Constellation	Pisces
Right ascension	23^h 49^m 12.52790^s[1]
Declination	02° 24′ 04.4072″[1]
Apparent magnitude (V)	8.93 - 9.03[2]
Characteristics
Spectral type	M1V Fe-1[3]
Variable type	BY Dra[2]
Astrometry
Radial velocity (Rv)	−71.79[4] km/s
Proper motion (μ)	RA: 992.665[4] mas/yr Dec.: −968.648[4] mas/yr
Parallax (π)	169.3585 ± 0.0595[4] mas
Distance	19.258 ± 0.007 ly (5.905 ± 0.002 pc)
Absolute magnitude (MV)	+10.1[5]
Details
Mass	0.37[6] M☉
Radius	0.39[7] R☉
Luminosity (bolometric)	0.022[7] L☉
Surface gravity (log g)	4.86[7] cgs
Temperature	3,570[7] K
Metallicity [Fe/H]	−0.51±0.05[8] dex
Rotational velocity (v sin i)	2.25[9] km/s
Other designations
BR Piscium, BD+01°4774, GJ 908[10], HIP 117473[1], SAO 128397, PPM 174453, G 29-68, G 31-6, LHS 550[11], LTT 17014, PLX 5763[12], TYC 586-610-1[13], GSC 00586-00610, IRAS 23466+0207, 2MASS J23491255+0224037
Database references
SIMBAD	data

The variability of Gliese 908 was confirmed in 1994, although no period could be detected in its brightness changes.[14] It was entered into the General Catalogue of Variable Stars in 1997.[15]

Gliese 908 is a cool main sequence star, a red dwarf, with a spectral class of M1V Fe-1. The suffix indicates a noticeable deficiency in heavy elements.[3]

References

1. Perryman; et al. (1997). "HIP 117473". The Hipparcos and Tycho Catalogues.
2. 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: B/gcvs. Bibcode:2009yCat....102025S.
3. Keenan, Philip C.; McNeil, Raymond C. (1989). "The Perkins Catalog of Revised MK Types for the Cooler Stars". The Astrophysical Journal Supplement Series. 71: 245. Bibcode:1989ApJS...71..245K. doi:10.1086/191373.
4. Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
5. Boro Saikia, S.; Marvin, C. J.; Jeffers, S. V.; Reiners, A.; Cameron, R.; Marsden, S. C.; Petit, P.; Warnecke, J.; Yadav, A. P. (2018). "Chromospheric activity catalogue of 4454 cool stars. Questioning the active branch of stellar activity cycles". Astronomy and Astrophysics. 616: A108. arXiv:1803.11123. Bibcode:2018A&A...616A.108B. doi:10.1051/0004-6361/201629518. S2CID 118915212.
6. Perger, M.; García-Piquer, A.; Ribas, I.; Morales, J. C.; Affer, L.; Micela, G.; Damasso, M.; Suárez-Mascareño, A.; González-Hernández, J. I.; Rebolo, R.; Herrero, E.; Rosich, A.; Lafarga, M.; Bignamini, A.; Sozzetti, A.; Claudi, R.; Cosentino, R.; Molinari, E.; Maldonado, J.; Maggio, A.; Lanza, A. F.; Poretti, E.; Pagano, I.; Desidera, S.; Gratton, R.; Piotto, G.; Bonomo, A. S.; Martinez Fiorenzano, A. F.; Giacobbe, P.; et al. (2017). "HADES RV Programme with HARPS-N at TNG. II. Data treatment and simulations". Astronomy and Astrophysics. 598: A26. arXiv:1610.08698. Bibcode:2017A&A...598A..26P. doi:10.1051/0004-6361/201628985. S2CID 56341358.
7. Maldonado, J.; Affer, L.; Micela, G.; Scandariato, G.; Damasso, M.; Stelzer, B.; Barbieri, M.; Bedin, L. R.; Biazzo, K.; Bignamini, A.; Borsa, F.; Claudi, R. U.; Covino, E.; Desidera, S.; Esposito, M.; Gratton, R.; González Hernández, J. I.; Lanza, A. F.; Maggio, A.; Molinari, E.; Pagano, I.; Perger, M.; Pillitteri, I.; Piotto, G.; Poretti, E.; Prisinzano, L.; Rebolo, R.; Ribas, I.; Shkolnik, E.; et al. (2015). "Stellar parameters of early-M dwarfs from ratios of spectral features at optical wavelengths". Astronomy and Astrophysics. 577: A132. arXiv:1503.03010. Bibcode:2015A&A...577A.132M. doi:10.1051/0004-6361/201525797. S2CID 53582613.
8. Lindgren, Sara; Heiter, Ulrike (2017). "Metallicity determination of M dwarfs. Expanded parameter range in metallicity and effective temperature". Astronomy and Astrophysics. 604: A97. arXiv:1705.08785. Bibcode:2017A&A...604A..97L. doi:10.1051/0004-6361/201730715. S2CID 119216828.
9. Houdebine, E. R. (2010). "Observation and modelling of main-sequence star chromospheres - XIV. Rotation of dM1 stars". Monthly Notices of the Royal Astronomical Society. 407 (3): 1657–1673. Bibcode:2010MNRAS.407.1657H. doi:10.1111/j.1365-2966.2010.16827.x.
10. Gliese, W.; Jahreiß, H. (1991). "Gl 908". Preliminary Version of the Third Catalogue of Nearby Stars.
11. Luyten, Willem Jacob (1979). "LHS 550". LHS Catalogue, 2nd Edition.
12. Van Altena W. F.; Lee J. T.; Hoffleit E. D. (1995). "GCTP 5763". The General Catalogue of Trigonometric Stellar Parallaxes (Fourth ed.).
13. Perryman; et al. (1997). "HIP 117473". The Hipparcos and Tycho Catalogues.
14. Weis, Edward W. (1994). "Long Term Variability in Dwarf M Stars". The Astronomical Journal. 107: 1135. Bibcode:1994AJ....107.1135W. doi:10.1086/116925.
15. Kazarovets, E. V.; Samus, N. N. (1997). "The 73rd Name-List of Variable Stars". Information Bulletin on Variable Stars. 4471: 1. Bibcode:1997IBVS.4471....1K.