10 Lacertae

10 Lacertae
Lacerta constellation map.svg
Red circle.svg
Location of 10 Lac (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Lacerta
Right ascension  22h 39m 15.67864s[1]
Declination +39° 03′ 00.9712″[1]
Apparent magnitude (V) 4.880[2]
Spectral type O9V[3]
U−B color index −1.010[2]
B−V color index −0.210[2]
Variable type β Cep?[4]
Radial velocity (Rv)−10.10[5] km/s
Proper motion (μ) RA: −0.32[1] mas/yr
Dec.: −5.46[1] mas/yr
Parallax (π)1.89 ± 0.22[1] mas
Distance715[6] pc
Absolute magnitude (MV)−4.40[7]
Mass26.9 M
Radius8.27 R
Luminosity102,000 L
Surface gravity (log g)4.03 cgs
Temperature36,000 K
Rotational velocity (v sin i)35 km/s
Other designations
10 Lac, HR 8622, BD+38°4826, HD 214680, SAO 72575, HIP 111841, NSV 25932, WDS J22393+3903
Database references

10 Lacertae (10 Lac) is a star in the constellation Lacerta. With an apparent magnitude of 4.9, it is located around 700 parsecs (2,300 ly) distant in the small Lacerta OB1 association. It is a hot blue main-sequence star of spectral type O9V, a massive star that is currently fusing its core hydrogen. It is a suspected Beta Cephei variable star.

10 Lacertae was one of the first O-type stars (along with S Monocerotis) to be defined as an anchor point for the MKK spectral classification; since the early twentieth century it has served as such a point. Specifically, the star is representative of O9V stars, meaning relatively cool O-type stars on the main-sequence.[8]

10 Lacertae has an 8th magnitude companion about one arc-minute away.[9]


  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:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.
  2. ^ a b c Oja, T. (September 1993). "UBV photometry of stars whose positions are accurately known. VII". Astronomy and Astrophysics Supplement Series. 100 (3): 591–592. Bibcode:1993A&AS..100..591O. ISSN 0365-0138.
  3. ^ Sota, A.; Maíz Apellániz, J.; Walborn, N. R.; Alfaro, E. J.; Barbá, R. H.; Morrell, N. I.; Gamen, R. C.; Arias, J. I. (2011). "The Galactic O-Star Spectroscopic Survey. I. Classification System and Bright Northern Stars in the Blue-violet at R ~ 2500". The Astrophysical Journal Supplement. 193 (3): 24. arXiv:1101.4002. Bibcode:2011ApJS..193...24S. doi:10.1088/0067-0049/193/2/24.
  4. ^ Samus, N. N.; Durlevich, O. V. (January 2009). "VizieR On-line Data Catalog: General Catalogue of Variable Stars". VizieR On-line Data Catalog. Bibcode:2009yCat....102025S.
  5. ^ Gontcharov, G. A. (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.
  6. ^ Kaltcheva, N.; Golev, V. (2011). "Improved Distances to Several Galactic OB Associations". Stellar Clusters & Associations: A RIA Workshop on Gaia.: 299–303. arXiv:1107.3758. Bibcode:2011sca..conf..299K.
  7. ^ a b Mokiem, M. R.; de Koter, A.; Puls, J.; Herrero, A.; Najarro, F.; Villamariz, M. R. (October 2005). "Spectral analysis of early-type stars using a genetic algorithm based fitting method". Astronomy and Astrophysics. 441 (2): 711–733. arXiv:astro-ph/0506751. Bibcode:2005A&A...441..711M. doi:10.1051/0004-6361:20053522.
  8. ^ Garrison, R. F. (1994). "A Hierarchy of Standards for the MK Process". Astronomical Society of the Pacific. 60: 3. Bibcode:1994ASPC...60....3G.
  9. ^ Dommanget, J.; Nys, O. (1994). "Catalogue of the Components of Double and Multiple stars (CCDM). First ion". Communications de l'Observatoire Royal de Belgique. 115. Bibcode:1994CoORB.115.....D.