HD 57821
| Observation data Epoch J2000.0 Equinox ICRS | |
|---|---|
| Constellation | Canis Major |
| Right ascension | 07h 22m 13.52901s |
| Declination | −19° 00′ 59.7646″ |
| Apparent magnitude (V) | 4.94 |
| Characteristics | |
| Evolutionary stage | Main sequence |
| Spectral type | B5 II/III or B7 IV |
| B−V color index | −0.039±0.024 |
| Astrometry | |
| Radial velocity (Rv) | +32.9±1.6 km/s |
| Proper motion (μ) | RA: −1.69 mas/yr Dec.: +6.91 mas/yr |
| Parallax (π) | 6.78±0.26 mas |
| Distance | 480 ± 20 ly (147 ± 6 pc) |
| Absolute magnitude (MV) | −0.90 |
| Details | |
| Mass | 4.12±0.08 M☉ |
| Radius | 4.7 R☉ |
| Luminosity | 489+43 −40 L☉ |
| Temperature | 12,445±86 K |
| Rotational velocity (v sin i) | 116 km/s |
| Age | 291 Myr |
| Other designations | |
| BD−18°1806, FK5 2570, HD 57821, HIP 35727, HR 2812, SAO 152776 | |
| Database references | |
| SIMBAD | data |
HD 57821 is a single star in the southern constellation of Canis Major. It has a blue-white hue and is faintly visible to the naked eye with an apparent visual magnitude of 4.94. Based on parallax measurements, the distance to this object is approximately 480 light years. It is drifting further away with a radial velocity of +33 km/s, having come to within 71 light-years some 4.3 million years ago.
The stellar classification of this star is B5 II/III, which matches the spectrum of a giant/bright giant although stellar models suggest it may still be on the main sequence. It has over four times the mass of the Sun and is 291 million years old. The star has a high rate of spin, showing a projected rotational velocity of 116 km/s. It is radiating around 489 times the luminosity of the Sun from its photosphere at an effective temperature of 12,445 K.
References
- 1 2 3 4 5 6 7 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. XHIP record for this object at VizieR.
- 1 2 3 4 5 van Leeuwen, F. (November 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.
- 1 2 3 4 5 6 7 8 9 10 Zorec, J.; Royer, F. (January 2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy & Astrophysics, 537: A120, arXiv:1201.2052, Bibcode:2012A&A...537A.120Z, doi:10.1051/0004-6361/201117691, S2CID 55586789.
- 1 2 Houk, Nancy; Smith-Moore, M. (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 4, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1988mcts.book.....H.
- ↑ Cowley, A. (November 1972), "Spectral classification of the bright B8 stars", Astronomical Journal, 77: 750–755, Bibcode:1972AJ.....77..750C, doi:10.1086/111348.
- ↑ Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics, 367 (2) (Third ed.): 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451, S2CID 425754
- 1 2 Gontcharov, G. A. (November 2012), "Spatial distribution and kinematics of OB stars", Astronomy Letters, 38 (11): 694–706, arXiv:1606.09028, Bibcode:2012AstL...38..694G, doi:10.1134/S1063773712110035, S2CID 119108982.
- ↑ "HD 57821". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-01-18.
- ↑ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
