Tau Pegasi

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Tau Pegasi
Pegasus constellation map.svg
Red circle.svg

Location of τ Pegasi (circled)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Pegasus
Right ascension 23h 20m 38.24188s[1]
Declination +23° 44′ 25.2098″[1]
Apparent magnitude (V) +4.58[2]
Spectral type A5 Vp[3]
U−B color index +0.13[4]
B−V color index +0.17[4]
Variable type δ Sct[5]
Radial velocity (Rv) +15.20 ± 1.6[6] km/s
Proper motion (μ) RA: 29.45 ± 0.33[1] mas/yr
Dec.: –9.53 ± 0.27[1] mas/yr
Parallax (π) 20.17 ± 0.40[1] mas
Distance 162 ± 3 ly
(49.6 ± 1.0 pc)
Absolute magnitude (MV) 1.10[2]
Mass 2.14[7] M
Radius 2.8[8] R
Luminosity 32[7] L
Surface gravity (log g) 3.88[9] cgs
Temperature 7,709[7] K
Metallicity [Fe/H] -0.28[2] dex
Rotational velocity (v sin i) 149[7] km/s
Other designations
62 Pegasi, BD+22°4810, FK5 880, GC 32503, HIP 115250, HR 8880, HD 220061, SAO 91186
Database references

Tau Pegasi (τ Peg, τ Pegasi) is a 4.6 magnitude star in the constellation Pegasus. The star has also the traditional names Salm,[10] Kerb (or El Khereb) and Markab, a name shared with α Pegasi, k Puppis and κ Velorum.[11] τ Pegasi belongs to the spectral class A5 Vp,[3] making it an A-type main sequence star.

This is a Delta Scuti variable star with a pulsation period of 0.94 hours. It is rotating rapidly with a projected rotational velocity of 150 km s−1. Tau Pegasi is radiating nearly 30 times the luminosity of the Sun from its outer atmosphere at an effective temperature of 7,762 K.[12]


  1. ^ a b c d e van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752Freely accessible, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357 
  2. ^ a b c Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971Freely accessible. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015.  Vizier catalog entry
  3. ^ a b Hoffleit, D.; Warren, W. H. (1995). "VizieR Online Data Catalog: Bright Star Catalogue, 5th Revised Ed. (Hoffleit+, 1991)". VizieR On-line Data Catalog: V/50. Originally published in: 1964BS....C......0H. 5050. Bibcode:1995yCat.5050....0H. 
  4. ^ a b Mermilliod, J. C. (2006). "VizieR Online Data Catalog: Homogeneous Means in the UBV System (Mermilliod 1991)". VizieR On-line Data Catalog: II/168. Originally published in: Institut d'Astronomie. 2168. Bibcode:2006yCat.2168....0M. Vizier catalog entry
  5. ^ 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....1.2025S. 
  6. ^ Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. 
  7. ^ a b c d Zorec, J.; Royer, F. (2012). "Rotational velocities of A-type stars". Astronomy & Astrophysics. 537: A120. arXiv:1201.2052Freely accessible. Bibcode:2012A&A...537A.120Z. doi:10.1051/0004-6361/201117691.  Vizier catalog entry
  8. ^ Allende Prieto, C.; Lambert, D. L. (1999). "Fundamental parameters of nearby stars from the comparison with evolutionary calculations: Masses, radii and effective temperatures". Astronomy and Astrophysics. 352: 555. arXiv:astro-ph/9911002Freely accessible. Bibcode:1999A&A...352..555A.  Vizier catalog entry
  9. ^ David, Trevor J.; Hillenbrand, Lynne A. (2015). "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets". The Astrophysical Journal. 804 (2): 146. arXiv:1501.03154Freely accessible. Bibcode:2015ApJ...804..146D. doi:10.1088/0004-637X/804/2/146.  Vizier catalog entry
  10. ^ Allen, Richard Hinckley (1899). Star-names and their meanings. New York, Leipzig [etc.] G.E. Stechert. p. 329. 
  11. ^ Kostjuk, N. D. (2004). "VizieR Online Data Catalog: HD-DM-GC-HR-HIP-Bayer-Flamsteed Cross Index (Kostjuk, 2002)". VizieR On-line Data Catalog: IV/27A. Originally published in: Institute of Astronomy of Russian Academy of Sciences (2002). 4027. Bibcode:2004yCat.4027....0K. 
  12. ^ Balona, L. A.; Dziembowski, W. A. (October 1999), "Excitation and visibility of high-degree modes in stars", Monthly Notices of the Royal Astronomical Society, 309 (1): 221–232, Bibcode:1999MNRAS.309..221B, doi:10.1046/j.1365-8711.1999.02821.x