Sigma Canis Majoris

σ Canis Majoris
Location of σ Canis Majoris (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Canis Major
Right ascension 07h 01m 43.14804s
Declination −27° 56′ 05.3892″
Apparent magnitude (V) 3.43 to 3.51
Characteristics
Evolutionary stage Supergiant
Spectral type K5 Ib
U−B color index +1.88
B−V color index +1.73
Variable type LC
Astrometry
Radial velocity (Rv)+22.11 km/s
Proper motion (μ) RA: −5.714 mas/yr
Dec.: +4.890 mas/yr
Parallax (π)2.5085±0.1590 mas
Distance1,290+76
−80
 ly
(395.6+23.2
−24.4
 pc)
Absolute magnitude (MV)−5.14
Details
Mass5.61+0.51
−0.49
 M

8.4±1.0, 9.1±2.0 M
Radius297 R
Luminosity15,800 L
Surface gravity (log g)0.32 cgs
Temperature3,792±125 K
Metallicity [Fe/H]+0.16 dex
Age83.2 Myr
Other designations
Nganurganity, Unurgunite, σ CMa, 22 CMa, CD−27°3544, FK5 1183, HD 52877, HIP 33856, HR 2646, SAO 172797, ADS 5719
Database references
SIMBADdata

Sigma Canis Majoris is a variable star in the southern constellation of Canis Major. It has the proper name Nganurganity [ˈŋanuɾˌɡ̊aniɟ̊] (historically written Unurgunite /ˌʌnərˈɡʌnt/); Sigma Canis Majoris is its Bayer designation. This star is located at a distance of approximately 1,290 light-years (400 parsecs) from the Sun. It has an apparent visual magnitude varying between 3.43 and 3.51, which is bright enough to be seen with the naked eye. The star is drifting further away with a line of sight velocity of +22 km/s.