26 Canis Majoris

26 Canis Majoris

A light curve for MM Canis Majoris from Hipparcos data, adapted from Aerts et al. (1999)[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Canis Major
Right ascension 07h 12m 12.21483s[2]
Declination −25° 56′ 33.3107″[2]
Apparent magnitude (V) 5.89[3] or (5.84 – 5.87)[4]
Characteristics
Spectral type B2 IV/V[5]
B−V color index −0.170±0.004[6]
Variable type SPB[4]
Astrometry
Radial velocity (Rv)+21.6±2.9[6] km/s
Proper motion (μ) RA: −5.678[2] mas/yr
Dec.: +8.929[2] mas/yr
Parallax (π)3.2442 ± 0.0841 mas[2]
Distance1,010 ± 30 ly
(308 ± 8 pc)
Absolute magnitude (MV)−1.11[6]
Details
Mass5.5±0.9[7] M☉
Radius3.25[3] R☉
Luminosity1,000+995
−499[7] L☉
Surface gravity (log g)3.777±0.027[8] cgs
Temperature16,157±200[8] K
Rotation2.729±0.001[7]
Rotational velocity (v sin i)64±14[8] km/s
Age3.6±3.3[9] Myr
Other designations
26 CMa, MM CMa, BD−25°4191, GC 9545, HD 55522, HIP 34798, HR 2718, SAO 173193[10]
Database references
SIMBADdata

26 Canis Majoris is a variable star in the southern constellation of Canis Major,[10] located around 1,010 light years away from the Sun.[2] It has the variable star designation MM Canis Majoris; 26 Canis Majoris is the Flamsteed designation.[10] This object is visible to the naked eye as a dim, blue-white hued star with a baseline apparent visual magnitude of 5.89.[3] It is moving further from the Earth with a heliocentric radial velocity of +22 km/s.[6]

With a stellar classification of B2 IV/V,[5] it appears as a B-type main-sequence star intermixed with traits of an evolving subgiant star. Samus et al. (2017) classify it as a slowly pulsating B-type variable star (SPB), which ranges from magnitude 5.84 down to 5.87 with a rotationally-modulated period of 2.72945 days.[4] Briquet et al. (2007) describe it as a chemically peculiar He-variable star, having inhomogeneous distributions of chemical elements across its surface. It has a variable, quasi-dipolar magnetic field, resulting in variations of the magnetic field and line strengths as it rotates.[7]

This star is around 3.6[9] million years old with a rotation period of 2.7 days.[7] It has 5.5[7] times the mass of the Sun and 3.25[3] times the Sun's radius. The star is radiating 1,000[7] times as much luminosity as the Sun from its photosphere at an effective temperature of 16,157 K.[8]

  1. ^ Cite error: The named reference Aerts was invoked but never defined (see the help page).
  2. ^ a b c d e f Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  3. ^ a b c d Cite error: The named reference Shulyak2014 was invoked but never defined (see the help page).
  4. ^ a b c Cite error: The named reference Samus2017 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference houk1978 was invoked but never defined (see the help page).
  6. ^ a b c d Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  7. ^ a b c d e f g Cite error: The named reference Briquet2007 was invoked but never defined (see the help page).
  8. ^ a b c d Cite error: The named reference Huang2010 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference Tetzlaff2011 was invoked but never defined (see the help page).
  10. ^ a b c Cite error: The named reference SIMBAD was invoked but never defined (see the help page).