Beta Equulei, Latinized from β Equulei, is the Bayer designation for a solitary[9] star in the northern constellation of Equuleus. It is faintly visible to the naked eye with an apparent visual magnitude of 5.16.[2] The annual parallax shift is 11.27 mas,[1] indicating a separation of around 289 light years from the Sun. It is drifting closer with a radial velocity of −11 km/s.[6]
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Equuleus |
| Right ascension | 21h 22m 53.61365s[1] |
| Declination | +06° 48′ 40.1125″[1] |
| Apparent magnitude (V) | 5.16[2] |
| Characteristics | |
| Evolutionary stage | Main sequence[3] |
| Spectral type | A3 V[4] |
| U−B color index | +0.10[5] |
| B−V color index | +0.064±0.003[2] |
| Astrometry | |
| Radial velocity (Rv) | −11.1±0.8[6] km/s |
| Proper motion (μ) | RA: +53.685[1] mas/yr Dec.: +10.136[1] mas/yr |
| Parallax (π) | 11.2696 ± 0.2608 mas[1] |
| Distance | 289 ± 7 ly (89 ± 2 pc) |
| Absolute magnitude (MV) | +0.13[2] |
| Details | |
| Mass | 2.74±0.04[3] M☉ |
| Radius | 4.02[7] R☉ |
| Luminosity | 78.3[2] L☉ |
| Temperature | 9,000[7] K |
| Rotational velocity (v sin i) | 58.0±0.7[4] km/s |
| Age | 600[7] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is an ordinary A-type main sequence star with a stellar classification of A3 V.[4] It has 2.7 times the mass of the Sun[3] and about four[7] times the Sun's radius. The star is around 600[7] million years old – 93%[3] of the way through its main sequence lifetime – and is spinning with a projected rotational velocity of 58 km/s.[4] It is radiating 78[2] times the luminosity of the Sun from its photosphere at an effective temperature of about 9,000 K.[7] The star emits an infrared excess indicating the presence of a dusty debris disk. The mean temperature of the dust is 85 K, indicating the semimajor axis of its orbit is 104 AU.[7]
β Equulei has four optical companions. They are not physically associated with the star described above.[10]
References
edit- ^ a b c d e f Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ a b c d e f 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.
- ^ a b c d Zorec, J.; Royer, F. (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.
- ^ a b c d Díaz, C. G.; et al. (July 2011), "Accurate stellar rotational velocities using the Fourier transform of the cross correlation maximum", Astronomy & Astrophysics, 531: A143, arXiv:1012.4858, Bibcode:2011A&A...531A.143D, doi:10.1051/0004-6361/201016386, S2CID 119286673.
- ^ Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data, SIMBAD, Bibcode:1986EgUBV........0M.
- ^ a b Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35,495 Hipparcos stars in a common system", Astronomy Letters, 32 (11): 759–771, arXiv:1606.08053, Bibcode:2006AstL...32..759G, doi:10.1134/S1063773706110065, S2CID 119231169.
- ^ a b c d e f g Rhee, Joseph H.; et al. (May 2007), "Characterization of Dusty Debris Disks: The IRAS and Hipparcos Catalogs", The Astrophysical Journal, 660 (2): 1556–1571, arXiv:astro-ph/0609555, Bibcode:2007ApJ...660.1556R, doi:10.1086/509912, S2CID 11879505.
- ^ "bet Equ". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-02-17.
{{cite web}}: CS1 maint: postscript (link) - ^ 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.
- ^ Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122 (6): 3466–3471, Bibcode:2001AJ....122.3466M, doi:10.1086/323920.
External links
edit- Kaler, James B. (December 18, 2009), "Beta Equulei", Stars, University of Illinois.