Kappa Canis Majoris

Kappa Canis Majoris
Location of κ Canis Majoris (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Canis Major
Right ascension 06h 49m 50.45933s[1]
Declination −32° 30′ 30.5225″[1]
Apparent magnitude (V) +3.87[2]
Characteristics
Spectral type B1.5 Ve[3]
U−B color index −0.97[2]
B−V color index −0.20[2]
Variable type γ Cas[3]
Astrometry
Radial velocity (Rv)+14.0±4.1[4] km/s
Proper motion (μ) RA: −8.84[1] mas/yr
Dec.: +3.73[1] mas/yr
Parallax (π)4.95 ± 0.12 mas[1]
Distance660 ± 20 ly
(202 ± 5 pc)
Absolute magnitude (MV)−3.03[5]
Details
Mass12.2±0.3[6] M☉
Radius5.9[7] R☉
Luminosity (bolometric)18,876[8] L☉
Surface gravity (log g)4.07[7] cgs
Temperature24,600[7] K
Age13.3±1.2[6] Myr
Other designations
κ CMa, 13 Canis Majoris, CD−32°3404, FK5 1180, GC 8946, HD 50013, HIP 32759, HR 2538, SAO 197258[9]
Database references
SIMBADdata

Kappa Canis Majoris, Latinized from κ Canis Majoris, is a solitary,[10] blue-white hued star in the constellation Canis Major. It is visible to the naked eye with an apparent visual magnitude of +3.87.[2] Based upon an annual parallax shift of 7.70 mas as seen from Earth,[1] this star is located about 660 light years from the Sun.

A light curve for Kappa Canis Majoris. The main plot, from Hipparcos data,[11] shows the long-term variability and the inset plot, from TESS data,[12] shows the short-term variability.

This is a B-type main-sequence star with a stellar classification of B1.5 Ve,[3] although Hiltner et al. (1969) classified it as B1.5 IVe[13] suggesting it is a subgiant star. The 'e' suffix indicates it is a rapidly rotating Be star with a circumstellar decretion disk of heated gas.[7] The radius of the emitting disk is about 0.20±0.06 AU, or about 3.7 times the radius of the star.[14] It is classified as a Gamma Cassiopeiae type variable star and its brightness varies from magnitude +3.4 to +3.97.[3] The star became 50% brighter between 1963 and 1978, increasing from magnitude 3.96 or so to 3.52.[15]

  1. ^ a b c d e f Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference Feinstein1979 was invoked but never defined (see the help page).
  3. ^ a b c d Cite error: The named reference AAVSOkap was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference deBruijne2012 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Tetzlaff2011 was invoked but never defined (see the help page).
  7. ^ a b c d Cite error: The named reference Meilland2009 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Hohle2010 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference HipDataAccess was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference MAST was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Hiltner1969 was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference rivinius2013 was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference kalerkap was invoked but never defined (see the help page).