15 Canis Majoris

Summary

15 Canis Majoris is a variable star in the southern constellation of Canis Major,[8] located roughly 1,200 light years away from the Sun.[2] It has the variable star designation EY Canis Majoris; 15 Canis Majoris is the Flamsteed designation. The star is visible to the naked eye as a faint, blue-white hued star with a baseline apparent visual magnitude of +4.82.[3] It is moving away from the Earth with a heliocentric radial velocity of 28 km/s.[7]

15 Canis Majoris

A visual band light curve for EY Canis Majoris (1992)[1]
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Canis Major
Right ascension 06h 53m 32.907s[2]
Declination −20° 13′ 27.32″[2]
Apparent magnitude (V) +4.82[3]
Characteristics
Spectral type B1 Ib[4]
U−B color index -0.96[5]
B−V color index −0.212±0.013[3]
Variable type β Cep[4][6]
Astrometry
Radial velocity (Rv)28.00[7] km/s
Proper motion (μ) RA: −5.46±0.16[2] mas/yr
Dec.: +3.58±0.17[2] mas/yr
Parallax (π)2.68 ± 0.24 mas[2]
Distance1,200 ± 100 ly
(370 ± 30 pc)
Absolute magnitude (MV)−3.02[3]
Details[4]
Mass12.8±1.2 M
Radius6.8±1.2 R
Luminosity20,000+12,000
−7,400
 L
Surface gravity (log g)3.89±0.20 cgs
Temperature26,100±1,200 K
Rotational velocity (v sin i)20±12 km/s
Other designations
15 CMa, EY CMa, BD−20°1616, FK5 2532, GC 9034, HD 50707, HIP 33092, HR 2571, SAO 172520[8]
Database references
SIMBADdata

This is a B-type supergiant star with a stellar classification of B1 Ib.[4] It is classified as a Beta Cephei type variable star and its brightness varies from magnitude +4.79 down to +4.84 with a period of 4.430 h.[6] The star has 12.8 times the mass of the Sun and 6.8 times the Sun's radius. It is radiating 20,000 times the luminosity of the Sun from its photosphere at an effective temperature of 26,100 K.[4]

References edit

  1. ^ Heynderickx, D. (December 1992). "A photometric study of beta Cephei stars. I. Frequency analyses". Astronomy & Astrophysics Supplement Series. 96: 207–254. Bibcode:1992A&AS...96..207H. Retrieved 14 November 2021.
  2. ^ 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. S2CID 18759600. Archived from the original on 2016-04-02. Vizier catalog entry
  3. ^ a b c d 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.
  4. ^ a b c d e Hubrig, S.; et al. (January 2009), "New magnetic field measurements of beta Cephei stars and Slowly Pulsating B stars", Astronomische Nachrichten, 330 (4): 317, arXiv:0902.1314, Bibcode:2009AN....330..317H, doi:10.1002/asna.200811187, S2CID 17497112
  5. ^ Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode:1986EgUBV........0M.
  6. ^ a b Samus, N. N.; et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1, 61 (1): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID 125853869.
  7. ^ a b 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. S2CID 119231169.
  8. ^ a b "15 CMa". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved April 30, 2019.