Theta Canis Majoris

Theta Canis Majoris

Template:Location mark Location of θ Canis Majoris (circled)
Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Canis Major
Right ascension	Template:RA
Declination	Template:DEC
Apparent magnitude (V)	4.08
Characteristics
Evolutionary stage	Red giant branch
Spectral type	K4 III
U−B Template:Engvar	+1.69
B−V Template:Engvar	+1.43
Astrometry
Radial velocity (Rv)	Template:Val km/s
Proper motion (μ)	RA: −136.454 mas/yr Dec.: −14.322 mas/yr
Parallax (π)	12.0676±0.62 mas
Distance	Template:Rnd ± Template:Rnd ly (Template:Rnd ± Template:Rnd pc)
Absolute magnitude (MV)	Template:Val
Details
Mass	Template:Val Template:Solar mass
Radius	Template:Val Template:Solar radius
Luminosity	Template:Val Template:Solar luminosity
Surface gravity (log g)	Template:Val cgs
Temperature	Template:Val K
Metallicity [Fe/H]	Template:Val dex
Rotational velocity (v sin i)	Template:Val km/s
Age	Template:Val Gyr
Metallicity [Fe/H]	{{{metal_fe2}}} dex
Other designations
Template:Odlist
Database references
SIMBAD	data

Theta Canis Majoris (θ Canis Majoris) is a solitary, orange-hued star near the northern edge of the constellation Canis Major, forming the nose of the "dog". The star is visible to the naked eye with an apparent visual magnitude of 4.08. Based upon an annual parallax shift of 12.07 mas as seen from Earth, it is located about 270 light years from the Sun. The star is moving away from Earth with a radial velocity of +96.2 km/s.

This is a evolved K-type giant star with a stellar classification of K4 III. Theta Canis Majoris is 5% less massive than the Sun, but has expanded to 33 times the Sun's size. This old star, around ten billion years old, is over two times older than the Solar System. It irradiates 305 times the Sun's luminosity from its expanded photosphere at an effective temperature of 4,200 K. This temperature gives it the cool orange hue of a K-type star.