Gamma Coronae Borealis
Epoch J2000.0 Equinox J2000.0 (ICRS)
|Right ascension||15h 42m 44.57s|
|Declination||+26° 17′ 44.3″|
|Apparent magnitude (V)||3.84|
8 CrB, HD 140436, HIP 76952, HR 5849, BD+26 2722, SAO 83958
Gamma Coronae Borealis (γ CrB) is a star in the constellation Corona Borealis. A spectroscopic binary system, its components orbit each other every 92.94 years and are roughly as far apart from each other as the Sun and Neptune. The individual stars have visual magnitudes of 4.04 and 5.60, and spectral types B9V and A3V.
When discovered to be variable in 1970, it was classified as a Delta Scuti variable with the earliest known spectral type of any known variable at the time and an amplitude of 0.05 magnitudes, but it was soon realized that the nature of its variations was likely different from other Delta Scuti variables. It is now known that stars with such spectral types can have pulsations similar to those of Delta Scuti variables.
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- Kaler, James B. (25 July 2008). "Gamma Coronae Borealis". Stars. University of Illinois. Retrieved 18 November 2014.
- Cvetkovic, Z.; Ninkovic, S. (2010). "On the Component Masses of Visual Binaries". Serbian Astronomical Journal. 180: 71–80. Bibcode:2010SerAJ.180...71C. doi:10.2298/SAJ1080071C.
- Malkov, O. Yu.; Tamazian, V.S.; Docobo, J.A.; Chulkov, D.A. (2012). "Dynamical masses of a selected sample of orbital binaries". Astronomy & Astrophysics. 546: 5. Bibcode:2012A&A...546A..69M. doi:10.1051/0004-6361/201219774. A69.
- Percy, John R. (February 1970). "The Light Variation of γ Coronae Borealis". Publications of the Astronomical Society of the Pacific. 82: 126. Bibcode:1970PASP...82..126P. doi:10.1086/128893.
- Veto, B.; Kovacs, G. (October 1981). "Standstill of gamma CrB". Information Bulletin on Variable Stars (2030): 1. Bibcode:1981IBVS.2030....1V.
- Lehmann, H.; Scholz, G.; Hildebrandt, G.; Yang, S. (November 1997). "The RV-variations of γ Coronae Borealis - a frequency analysis". Astronomy and Astrophysics. 327: 167–172. Bibcode:1997A&A...327..167L.
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