DG Canum Venaticorum

DG Canum Venaticorum is the variable star designation for a binary star[2] system in the northern constellation of Canes Venatici. As of 2009, the pair have an angular separation of 0.20″ along a position angle of 285°, which corresponds to a physical separation of around 3.6 AU.[7] With an apparent visual magnitude of 12.02, the pair are much too faint to be seen with the naked eye.[2] Parallax measurements place the system at a distance of roughly 59 light years from the Earth.[2]

DG Canum Venaticorum
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Canes Venatici
Right ascension  13h 31m 46.617s[1]
Declination +29° 16′ 36.72″[1]
Apparent magnitude (V) 12.02[2] (12.64 + 12.93)
Characteristics
Spectral type M4.0Ve[2]
Variable type Flare star + BY Dra[3]
Astrometry
Radial velocity (Rv)−7.50±6.50[2] km/s
Proper motion (μ) RA: −244.1±4.2[2] mas/yr
Dec.: −132.4±4.8[2] mas/yr
Parallax (π)55.51 ± 2.38[2] mas
Distance59 ± 3 ly
(18.0 ± 0.8 pc)
Absolute magnitude (MV)10.74[2] (11.36 + 11.65)
Details
A
Mass0.39[4] M☉
Radius0.253[5] R☉
Temperature3,263[5] K
Metallicity [Fe/H]0.15[6] dex
Rotational velocity (v sin i)50[7] km/s
B
Mass+0.07[5] M☉
Age30[7] Myr
Other designations
DG CVn, G 165-8AB, GJ 3789, TYC 2003-139-1[8]
Database references
SIMBADdata
ARICNSdata

The stellar classification of the primary component is M4.0Ve, indicating it is a red dwarf with emission lines present. It is considered a very young system with an estimated age of just 30[7] million years and a higher metallicity than the Sun.[6] One of the components is rotating rapidly, with a projected rotational velocity of 50 km/s.[2] At least one of the members of this system is a type of variable known as a flare star, which means it undergoes brief increases in brightness at random intervals. On April 23, 2014, a gamma-ray superflare event was observed by the Swift satellite coming from the position of this system. It may have been perhaps the most luminous such events ever observed coming from a red dwarf star. A secondary radio flare was observed a day later.[7]

References
  1. Høg, E.; et al. (March 2000), "The Tycho-2 catalogue of the 2.5 million brightest stars", Astronomy and Astrophysics, 355: L27–L30, Bibcode:2000A&A...355L..27H, doi:10.1888/0333750888/2862, ISBN 0333750888.
  2. Riedel, Adric R.; et al. (2014), "The Solar Neighborhood. XXXIII. Parallax Results from the CTIOPI 0.9 m Program: Trigonometric Parallaxes of Nearby Low-mass Active and Young Systems", The Astronomical Journal, 147 (4): 85, arXiv:1401.0722, Bibcode:2014AJ....147...85R, doi:10.1088/0004-6256/147/4/85.
  3. 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.
  4. Cortés-Contreras, M; Béjar, V. J. S; Caballero, J. A; Gauza, B; Montes, D; Alonso-Floriano, F. J; Jeffers, S. V; Morales, J. C; Reiners, A; Ribas, I; Schöfer, P; Quirrenbach, A; Amado, P. J; Mundt, R; Seifert, W (2017). "CARMENES input catalogue of M dwarfs. II. High-resolution imaging with Fast Cam". Astronomy & Astrophysics. 597: A47. arXiv:1608.08145. Bibcode:2017A&A...597A..47C. doi:10.1051/0004-6361/201629056.
  5. Houdebine, E. R; Mullan, D. J; Paletou, F; Gebran, M (2016). "Rotation-Activity Correlations in K and M Dwarfs. I. Stellar Parameters and Compilations of v sin i and P/sin i for a Large Sample of Late-K and M Dwarfs". The Astrophysical Journal. 822 (2): 97. arXiv:1604.07920. Bibcode:2016ApJ...822...97H. doi:10.3847/0004-637X/822/2/97.
  6. Newton, Elisabeth R.; et al. (January 2014), "Near-infrared Metallicities, Radial Velocities, and Spectral Types for 447 Nearby M Dwarfs", The Astronomical Journal, 147 (1): 24, arXiv:1310.1087, Bibcode:2014AJ....147...20N, doi:10.1088/0004-6256/147/1/20, 20.
  7. Fender, R. P.; et al. (January 2015), "A prompt radio transient associated with a gamma-ray superflare from the young M dwarf binary DG CVn", Monthly Notices of the Royal Astronomical Society: Letters, 446 (1): L66–L70, arXiv:1410.1545, Bibcode:2015MNRAS.446L..66F, doi:10.1093/mnrasl/slu165.
  8. "DG CVn -- Flare Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2016-03-11.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.