HR 6902

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HR 6902
Observation data
Epoch J2000      Equinox J2000
Constellation Ophiuchus
Right ascension 18h 25m 38.799s[1]
Declination +08° 01′ 55.23″[1]
Apparent magnitude (V) +5.64[2]
Characteristics
Spectral type G9IIb / B8V
Variable type Zeta Aurigae-type
Astrometry
Proper motion (μ) RA: -4.07 ± 0.54[1] mas/yr
Dec.: -6.34 ± 0.31[1] mas/yr
Parallax (π) 4.14 ± 0.41[1] mas
Distance 790 ± 80 ly
(240 ± 20 pc)
Absolute magnitude (MV) –1.33[2]
Details
Mass 3.86/2.95[3] M
Radius 33/3[3] R
Luminosity 562/146 L
Temperature 4900/11600[3] K
Orbit
Period (P) 1.055[3] yr
Semi-major axis (a) 1.96[3] Astronomical Units"
Eccentricity (e) 0.311[3]
Inclination (i) 87[3]°
Other designations
V* V2291 Oph, GSC 01023-02454, HD 169690, HD 169689, 2MASS J18253880+0801551, BD+07 3682, FK5 1478, PPM 165790, HIP 90313, SAO 123462
Database references
SIMBAD data

HR 6902 (also designated V2291 Oph) is a binary system located 790 light years away[1] from the Sun in the Ophiuchus constellation. The system includes an orange bright giant star and a B-type main sequence star, forming an eclipsing binary of Zeta Aurigae type. The system is also surrounded by a warm circumstellar envelope and the spectra show silicon and carbon absorption up to a distance of 3.3 giant radii.[3]

References[edit]

  1. ^ a b c d e f van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.  Vizier catalog entry
  2. ^ a b Jasniewicz, G. et al. (February 1999), Late-type giants with infrared excess. I. Lithium abundances, Astronomy and Astrophysics 342: 831–838, Bibcode:1999A&A...342..831J 
  3. ^ a b c d e f g h Kirsch et al.; Baade, R.; Reimers, D. (2001). "The warm circumstellar envelope and wind of the G9 IIb star HR 6902". Astronomy and Astrophysics 379 (3): 925–935. arXiv:astro-ph/0008378. Bibcode:2001A&A...379..925K. doi:10.1051/0004-6361:20011117.