DG Canum Venaticorum is a variable binary star system[3] 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.[8] With an apparent visual magnitude of 12.02, the pair are much too faint to be seen with the naked eye.[3] Parallax measurements place the system at a distance of roughly 59 light years from the Earth.[3]
 A light curve for DG Canum Venaticorum, plotted from TESS data.[1] The main plot shows both the low amplitude periodic oscillations, and several flares. The inset plot shows the strongest flare with an expanded time scale. | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Canes Venatici |
| Right ascension | 13h 31m 46.617s[2] |
| Declination | +29° 16′ 36.72″[2] |
| Apparent magnitude (V) | 12.02[3] (12.64 + 12.93) |
| Characteristics | |
| Spectral type | M4.0Ve[3] |
| Variable type | Flare star + BY Dra[4] |
| Astrometry | |
| Radial velocity (Rv) | −7.50±6.50[3] km/s |
| Proper motion (μ) | RA: −244.1±4.2[3] mas/yr Dec.: −132.4±4.8[3] mas/yr |
| Parallax (π) | 55.51 ± 2.38 mas[3] |
| Distance | 59 ± 3 ly (18.0 ± 0.8 pc) |
| Absolute magnitude (MV) | 10.74[3] (11.36 + 11.65) |
| Details | |
| A | |
| Mass | 0.39[5] M☉ |
| Radius | 0.253[6] R☉ |
| Temperature | 3,263[6] K |
| Metallicity [Fe/H] | 0.15[7] dex |
| Rotational velocity (v sin i) | 50[8] km/s |
| B | |
| Mass | +0.07[6] M☉ |
| Age | 30[8] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| ARICNS | data |
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[8] million years and a higher metallicity than the Sun.[7] One of the components is rotating rapidly, with a projected rotational velocity of 50 km/s.[3] 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.[8]
References
edit- ^ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 8 December 2021.
- ^ a b 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.
- ^ a b c d e f g h i j k 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.
- ^ 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.
- ^ 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, Ansgar; 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. S2CID 56332644.
- ^ a b c 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. S2CID 119118088.
- ^ a b 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.
- ^ a b c d e 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.
- ^ "DG CVn -- Flare Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2016-03-11.
External links
edit- Reddy, Francis (September 29, 2014), NASA's Swift Mission Observes Mega Flares from a Mini Star, NASA, retrieved 2016-03-12.