Astronomy:Beta Equulei
| Observation data 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[1] mas |
| 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 |
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]
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
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 3.0 3.1 3.2 3.3 Zorec, J.; Royer, F. (2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy & Astrophysics 537: A120, doi:10.1051/0004-6361/201117691, Bibcode: 2012A&A...537A.120Z.
- ↑ 4.0 4.1 4.2 4.3 Díaz, C. G. et al. (July 2011), "Accurate stellar rotational velocities using the Fourier transform of the cross correlation maximum", Astronomy & Astrophysics 531: A143, doi:10.1051/0004-6361/201016386, Bibcode: 2011A&A...531A.143D.
- ↑ Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data (SIMBAD), Bibcode: 1986EgUBV........0M.
- ↑ 6.0 6.1 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, doi:10.1134/S1063773706110065, Bibcode: 2006AstL...32..759G.
- ↑ 7.0 7.1 7.2 7.3 7.4 7.5 7.6 Rhee, Joseph H. et al. (May 2007), "Characterization of Dusty Debris Disks: The IRAS and Hipparcos Catalogs", The Astrophysical Journal 660 (2): 1556–1571, doi:10.1086/509912, Bibcode: 2007ApJ...660.1556R.
- ↑ "bet Equ". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=bet+Equ.
- ↑ 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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
- ↑ Mason, B. D. et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal 122 (6): 3466–3471, doi:10.1086/323920, Bibcode: 2001AJ....122.3466M.
External links
- Kaler, James B. (December 18, 2009), "Beta Equulei", Stars (University of Illinois), http://stars.astro.illinois.edu/sow/betaequ.html.
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