DG Canum Venaticorum is a variable binary star system[1] 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.[2] With an apparent visual magnitude of 12.02, the pair are much too faint to be seen with the naked eye.[1] Parallax measurements place the system at a distance of roughly 59 light years (18.0 parsecs) from the Earth.[1]

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[2] million years and a higher metallicity than the Sun.[3] One of the components is rotating rapidly, with a projected rotational velocity of 50 km/s.[1]

In 1999, Russell M. Robb et al. discovered that the star, then called GSC 2003_139, is a variable star, exhibiting both periodic and flare brightness variations.[4] Therefore, 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. It was given its variable star designation, DG Canum Venaticorum, in 2001.[5] 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.[2]

References

  1. ^ 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. S2CID 14115792
  2. ^ 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. S2CID 118483778
  3. ^ 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. S2CID 26818462. 20
  4. ^ Robb, R. M.; Balam, D. D.; Greimel, R. (May 1999). "1RXS J133146+291631 = G 165-8 is a M4Ve spotted star with a rotational period of about 0.10835 days and an amplitude in R of 0.03". Information Bulletin on Variable Stars. 4714: 1–4. Bibcode:1999IBVS.4714....1R. Retrieved 6 January 2025.
  5. ^ Kazarovets, E. V.; Samus, N. N.; Durlevich, O. V. (July 2001). "The 76th Name-List of Variable Stars". Information Bulletin on Variable Stars. 5135: 1–67. Bibcode:2001IBVS.5135....1K. Retrieved 6 January 2025.