HR 5110, also known as BH Canum Venaticorum, is a binary star[6] system in the northern constellation of Canes Venatici. It is visible to the naked eye with an apparent visual magnitude of 4.91.[3] Based upon an annual parallax shift of 21.90±0.23 mas,[2] it is located 149 light-years away. The system is moving further from the Sun with a heliocentric radial velocity of 6.4 km/s.[3]

HR 5110

A light curve for BH Canum Venaticorum, plotted from TESS data[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Canes Venatici
Right ascension 13h 34m 47.80827s[2]
Declination +37° 10′ 56.6979″[2]
Apparent magnitude (V) 4.91[3]
Characteristics
Spectral type kA6hF1mF2[4] (F2 IV + K0 IV)[5]
B−V color index 0.404±0.010[3]
Variable type RS CVn[5]
Astrometry
Radial velocity (Rv)6.43±0.24[3] km/s
Proper motion (μ) RA: +84.63[2] mas/yr
Dec.: −9.34[2] mas/yr
Parallax (π)21.90 ± 0.23 mas[2]
Distance149 ± 2 ly
(45.7 ± 0.5 pc)
Absolute magnitude (MV)1.61[3]
Orbit[6]
Period (P)2.613214 d
Semi-major axis (a)0.017 AU
Eccentricity (e)0.00
Inclination (i)171.1°
Longitude of the node (Ω)89±10°
Periastron epoch (T)2,445,766.655
Details
BH CVn A
Mass1.5[6] M
Radius2.6[6] R
Luminosity19.01[3] L
Surface gravity (log g)3.61±0.14[7] cgs
Temperature6,569±223[7] K
Metallicity [Fe/H]−0.20[3] dex
Age1.36[7] Gyr
BH CVn B
Mass0.8[6] M
Radius3.4[6] R
Other designations
BH CVn, BD+37° 2426, FK5 502, HD 118216, HIP 66257, HR 5110, SAO 63623[8]
Database references
SIMBADdata

This is a close binary system with an orbital period of 2.6 days and an orbital plane that is oriented nearly face-on.[6] It may be considered an Algol-type semidetached binary. The hotter primary component has a stellar classification of F2 IV,[5] indicating it is an evolving subgiant star that is leaving the main sequence after consuming the hydrogen at its core.

HR 5110 is classified as a RS Canum Venaticorum variable system, primarily due to chromospheric activity in the secondary component.[5] This star has a classification of K0 IV, matching a K-type subgiant star.[5] Based upon the close separation of the pair and the class of the secondary component, that latter is probably filling its roche lobe. This star is most likely the source of the radio emission from this system, and the alignment of this signal is consistent with a polar starspot.[6]

References

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  1. ^ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 8 December 2021.
  2. ^ 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, S2CID 18759600.
  3. ^ a b c d e f g h Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
  4. ^ Abt, Helmut A. (2009), "MK Classifications of Spectroscopic Binaries", The Astrophysical Journal Supplement, 180 (1): 117–18, Bibcode:2009ApJS..180..117A, doi:10.1088/0067-0049/180/1/117, S2CID 122811461.
  5. ^ a b c d e Ransom, R. R.; et al. (April 2003), "Very Long Baseline Interferometry Imaging of the RS Canum Venaticorum Binary Star System HR 5110", The Astrophysical Journal, 587 (1): 390–397, arXiv:astro-ph/0301413, Bibcode:2003ApJ...587..390R, doi:10.1086/368070, S2CID 18203880.
  6. ^ a b c d e f g h Abbuhl, E.; Mutel, R. L.; Lynch, C.; Güedel, M. (September 2015), "Radio Astrometry of the Close Active Binary HR5110", The Astrophysical Journal, 811 (1): 8, arXiv:1508.06654, Bibcode:2015ApJ...811...33A, doi:10.1088/0004-637X/811/1/33, S2CID 118373672, 33
  7. ^ a b c David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal, 804 (2): 146, arXiv:1501.03154, Bibcode:2015ApJ...804..146D, doi:10.1088/0004-637X/804/2/146, S2CID 33401607.
  8. ^ "V* BH CVn". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-06-07.