Gliese 208

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
Gliese 208
Observation data
Epoch J2000      Equinox J2000
Constellation Orion
Right ascension 05h 36m 30.991s[1]
Declination +11° 19′ 40.33″[1]
Apparent magnitude (V) 8.80 - 9.05[2]
Characteristics
Spectral type M0.0 Ve[3]
Variable type RS CVn[2]
Astrometry
Radial velocity (Rv) 21.772[4] km/s
Proper motion (μ) RA: −2.811 ± 0.080[1] mas/yr
Dec.: −56.368 ± 0.060[1] mas/yr
Parallax (π) 87.66 ± 0.29[1] mas
Distance 37.2 ± 0.1 ly
(11.41 ± 0.04 pc)
Absolute magnitude (MV) 8.6
Details
Mass 0.646[5] M
Radius 0.601[5] R
Luminosity 0.08[6] L
Temperature 3,966[5] K
Metallicity [Fe/H] +0.05[5] dex
Age 2.7[5] 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

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

The spectral type of Gj 208 has variously been described between K6 and M1.[7][8][9] Two of the most recent observations give a statistically calculated spectral type of K7.9[5] or a more traditional classification of M0.0 Ve.[3] It is a cool dwarf star and probably a spectroscopic binary.[2]

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.[10]

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.[2]

References[edit]

  1. ^ a b c d e 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. 
  2. ^ a b c d 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. 
  3. ^ a b 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:1206.5991Freely accessible. Bibcode:2013AJ....145..102L. doi:10.1088/0004-6256/145/4/102. 
  4. ^ 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:1302.1905Freely accessible. Bibcode:2013A&A...552A..64S. doi:10.1051/0004-6361/201220927. 
  5. ^ a b c d e f 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: 64. arXiv:1501.01635Freely accessible. Bibcode:2015ApJ...804...64M. doi:10.1088/0004-637X/804/1/64. 
  6. ^ 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: 343. arXiv:1208.2037Freely accessible. Bibcode:2012MNRAS.427..343M. doi:10.1111/j.1365-2966.2012.21873.x. 
  7. ^ 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. 
  8. ^ 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. 
  9. ^ 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. 
  10. ^ Bobylev, Vadim V. (March 2010). "Searching for Stars Closely Encountering with the Solar System". Astronomy Letters. 36 (3): 220–226. arXiv:1003.2160Freely accessible. Bibcode:2010AstL...36..220B. doi:10.1134/S1063773710030060. 

External links[edit]

  • Wikisky image of HD 245409 (Gliese 208)