10 Equ

Beta Equulei
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Equuleus
Right ascension  21h 22m 53.61344s[1]
Declination +06° 48′ 40.1070″[1]
Apparent magnitude (V) 5.15[2]
Spectral type A3 V[3]
U−B color index +0.10[2]
B−V color index +0.04[2]
Radial velocity (Rv)−11.1±0.8[4] km/s
Proper motion (μ) RA: −26.61[1] mas/yr
Dec.: +38.21[1] mas/yr
Parallax (π)24.55 ± 0.81[1] mas
Distance133 ± 4 ly
(41 ± 1 pc)
Absolute magnitude (MV)+0.13[5]
Radius4.02[6] R
Luminosity78.3[5] L
Temperature9,000[6] K
Rotational velocity (v sin i)58.0±0.7[3] km/s
Age600[6] Myr
Other designations
β Equ, 10 Equulei, BD+06° 4811, HD 203562, HIP 105570, HR 8178, SAO 126749, WDS 21229+0649A.[7]
Database references

Beta Equulei, Latinized from β Equulei, is the Bayer designation for a solitary[8] star in the northern constellation of Equuleus. It is faintly visible to the naked eye with an apparent visual magnitude of 5.15.[2] The annual parallax shift is 24.55 mas,[1] indicating a separation of around 133 light years from the Sun.

This is an ordinary A-type main sequence star with a stellar classification of A3 V.[3] It has about four times the radius of the Sun and an effective temperature of about 9,000 K.[6] The star is around 600[6] million years old and is spinning with a projected rotational velocity of 58 km/s.[3] 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.[6]

β Equulei has four optical companions. They are not physically associated with the star described above.[9]


  1. ^ a b c d e f van Leeuwen, F. (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.
  2. ^ a b c d Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data, SIMBAD, Bibcode:1986EgUBV........0M.
  3. ^ 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.
  4. ^ 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.
  5. ^ a b 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.
  6. ^ a b c d e f 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.
  7. ^ "bet Equ". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-02-17.
  8. ^ 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.
  9. ^ Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122: 3466–3471, Bibcode:2001AJ....122.3466M, doi:10.1086/323920.

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