Nu1 Canis Majoris

Nu1 Canis Majoris
Location of ν1 Canis Majoris (circled in red)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Canis Major
Right ascension 06h 36m 22.848s
Declination −18° 39′ 35.73″
Apparent magnitude (V) 5.704 (5.87 + 7.61)
Characteristics
Spectral type G8 III + F3 IV-V
B−V color index +0.815
Astrometry
Radial velocity (Rv)+26.13 km/s
Proper motion (μ) RA: −9.902 mas/yr
Dec.: +23.229 mas/yr
Parallax (π)12.3660±0.1985 mas
Distance264 ± 4 ly
(81 ± 1 pc)
Absolute magnitude (MV)+1.23
Details
ν1 CMa A
Mass1.41 M
Radius7.1±0.3 R
LuminosityL
Surface gravity (log g)3.00 cgs
Temperature6,091±822 K
Metallicity [Fe/H]−0.06 dex
Rotational velocity (v sin i)4.8±0.2 km/s
Age3.07 Gyr
Other designations
ν1 CMa, 6 Canis Majoris, BD−18°1480, GC 8614, HD 47138, HIP 31564, HR 2423, SAO 151694, ADS 5253, CCDM 06364-1840, WDS 06364-1840
Database references
SIMBADdata

Nu1 Canis Majoris is a binary star in the constellation Canis Major. Its name is a Bayer designation that is Latinized from ν1 Canis Majoris, and abbreviated Nu1 CMa or ν1 CMa. This system is visible to the naked eye as a point of light with an apparent visual magnitude of 5.7. Based on parallax shift of 12.366 mas as seen from Earth orbit, this system is approximately 264 light years from the Sun. It is drifting further away with a line of sight velocity of +26 km/s.

As of 2011, the pair had an angular separation of 17.29 arc seconds along a position angle of 264.2°. The yellow hued magnitude 5.87 primary, component A, is an evolved G-type giant star with a stellar classification of G8 III. It is an estimated 3 billion years old and has 1.4 times the mass of the Sun. Having exhausted the supply of hydrogen at its core, it has expanded to 7 times the Sun's radius and is radiating 8 times the luminosity of the Sun from its photosphere at an effective temperature of 6,091 K.

The magnitude 7.61 companion, component B, is a yellow-white hued F-type main sequence/subgiant hybrid with a class of F3 IV-V.