Mu Canis Majoris

Mu Canis Majoris
Location of μ Canis Majoris (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Canis Major
Right ascension 06h 56m 06.64589s[1]
Declination −14° 02′ 36.3520″[1]
Apparent magnitude (V) 5.12 (5.27 + 7.32)[2]
Characteristics
Spectral type K2/3 III + B9/A0 V[3]
Astrometry
Radial velocity (Rv)18.1±0.1[4] km/s
Proper motion (μ) RA: −1.59[1] mas/yr
Dec.: + 6.33[1] mas/yr
Parallax (π)2.62 ± 0.58 mas[1]
Distanceapprox. 1,200 ly
(approx. 380 pc)
Absolute magnitude (MV)−2.22[5]
Details
μ CMa A
Luminosity2489[6] L☉
Temperature4,441[6] K
Rotational velocity (v sin i)≤ 5[7] km/s
μ CMa B
Mass14.7±0.3[8] M☉
Age11.6±0.5[8] Myr
Other designations
μ CMa, 18 Canis Majoris, BD−13°1741, HIP 33345, HR 2593, SAO 152123[9]
μ CMa A: HD 51250[9]
μ CMa B: HD 51251[10]
Database references
SIMBADdata

Mu Canis Majoris (μ Canis Majoris) is a binary star[2] system in the southern constellation of Canis Major. The pair can be located a little to the southwest of the point midway between Gamma and Theta Canis Majoris,[11] and the components can be split with a small telescope.[12] The system is faintly visible to the naked eye with an apparent visual magnitude of 5.12.[2] Based upon an annual parallax shift of just 2.62 mas as seen from Earth,[1] this system is located roughly 1,200 light years from the Sun.

Grotius assigned the name Isis to this star, but the name, now obsolete, belonged rather to Gamma Canis Majoris.[13]

As of 2011, the pair had an angular separation of 2.77 arc seconds along a position angle of 343.9°.[14] The orange-hued primary member, component A, is an evolved K-type giant star with a stellar classification of K2/3 III[3] and a visual magnitude of 5.27.[2] The base magnitude 7.32[2] companion, component B, is a hybrid B/A-type main-sequence star with a class of B9/A0 V.[3]

The system has two visual companions. As of 2008, magnitude 10.32 component C lies at an angular separation of 86.90″, while magnitude 10.64 component D is at a separation of 105.0″.[15] Mu CMa should not be confused with the 9th magnitude variable star MU CMa located near NGC 2360.[16]

  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 e Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  3. ^ a b c Cite error: The named reference houk1978 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 ginestat2002 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference McDonald2012 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Eaton1990 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference Tetzlaff2011 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference SIMBAD_A was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference SIMBAD_B was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference OMeara2007 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference turnleft was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference allen was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference Mason2012 was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference Mason2014 was invoked but never defined (see the help page).
  16. ^ Cite error: The named reference AAVSO was invoked but never defined (see the help page).