Tau Canis Majoris information

Tau Canis Majoris
	Location of τ CMa (circled)
Observation data; Epoch J2000 Equinox J2000
Constellation	Canis Major
Right ascension	07h 18m 42.48642s
Declination	−24° 57′ 15.7413″
Apparent magnitude (V)	4.40 (4.89 + 5.33 + 9.70)
Characteristics
Spectral type	O9II (O9II + B0.5V + B0.5V)
U−B color index	−0.99
B−V color index	−0.15
Variable type	β Lyr
Astrometry
Radial velocity (Rv)	+33.80 km/s
Proper motion (μ)	RA: −2.31 mas/yr ; Dec.: 5.02 mas/yr
Parallax (π)	1.09 ± 0.59 mas
Distance	1,570 pc
Absolute magnitude (MV)	−5.9 + −3.6 + −3.6
Details
τ CMa Aa
Mass	50 M☉
Radius	19.8 R☉
Luminosity	280,000 L☉
Surface gravity (log g)	3.5 cgs
Temperature	32,000 K
τ CMa Ab1
Mass	17.8 M☉
τ CMa Ab2
Mass	17.8 M☉
Other designations
	30 Canis Majoris, HR 2782, HD 57061, CD−24°5176, HIP 35415, SAO 173446, GC 9736, ADS 5977, CCDM 07187-2457
Database references
SIMBAD	data

Tau Canis Majoris (τ CMa, τ Canis Majoris, 30 CMa) is a multiple star system in the constellation Canis Major. It is approximately 5,000 light years distant from Earth and is the brightest member of the open cluster NGC 2362.

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^ ^a ^b ^c Cite error: The named reference ducati was invoked but never defined (see the help page).
^ Cite error: The named reference wds was invoked but never defined (see the help page).
^ Cite error: The named reference gosss was invoked but never defined (see the help page).
^ ^a ^b Cite error: The named reference stickland was invoked but never defined (see the help page).
^ Cite error: The named reference gcvs was invoked but never defined (see the help page).
^ Cite error: The named reference Pourbaix was invoked but never defined (see the help page).
^ Cite error: The named reference Gudennavar was invoked but never defined (see the help page).
^ ^a ^b ^c Cite error: The named reference devries was invoked but never defined (see the help page).
^ ^a ^b Cite error: The named reference mnras189_601 was invoked but never defined (see the help page).
^ ^a ^b Cite error: The named reference hohle was invoked but never defined (see the help page).

[hipparcos-1] Cite error: The named reference hipparcos was invoked but never defined (see the help page).

[ducati-2] Cite error: The named reference ducati was invoked but never defined (see the help page).

[wds-3] Cite error: The named reference wds was invoked but never defined (see the help page).

[gosss-4] Cite error: The named reference gosss was invoked but never defined (see the help page).

[stickland-5] Cite error: The named reference stickland was invoked but never defined (see the help page).

[gcvs-6] Cite error: The named reference gcvs was invoked but never defined (see the help page).

[Pourbaix-7] Cite error: The named reference Pourbaix was invoked but never defined (see the help page).

[Gudennavar-8] Cite error: The named reference Gudennavar was invoked but never defined (see the help page).

[devries-9] Cite error: The named reference devries was invoked but never defined (see the help page).

[mnras189_601-10] Cite error: The named reference mnras189_601 was invoked but never defined (see the help page).

[hohle-11] Cite error: The named reference hohle was invoked but never defined (see the help page).

Observation data Epoch J2000 Equinox J2000
Location of τ CMa (circled)
Constellation	Canis Major
Right ascension	07^h 18^m 42.48642^s^[1]
Declination	−24° 57′ 15.7413″^[1]
Apparent magnitude (V)	4.40^[2] (4.89 + 5.33 + 9.70^[3])
Characteristics
Spectral type	O9II^[4] (O9II + B0.5V + B0.5V^[5])
U−B color index	−0.99^[2]
B−V color index	−0.15^[2]
Variable type	β Lyr^[6]
Astrometry

Radial velocity (R_v)	+33.80^[7] km/s
Proper motion (μ)	RA: −2.31^[1] mas/yr Dec.: 5.02^[1] mas/yr
Parallax (π)	1.09 ± 0.59 mas^[1]
Distance	1,570^[8] pc
Absolute magnitude (M_V)	−5.9 + −3.6 + −3.6^[5]

Details
τ CMa Aa
Mass	50^[9] `M`_☉
Radius	19.8^[10] `R`_☉
Luminosity	280,000^[11] `L`_☉
Surface gravity (log g)	3.5^[10] cgs
Temperature	32,000^[11] K


τ CMa Ab1
Mass	17.8^[9] `M`_☉


τ CMa Ab2
Mass	17.8^[9] `M`_☉

Other designations
30 Canis Majoris, HR 2782, HD 57061, CD−24°5176, HIP 35415, SAO 173446, GC 9736, ADS 5977, CCDM 07187-2457
Database references
SIMBAD	data

Tau Canis Majoris information

and 24 Related for: Tau Canis Majoris information

Tau Canis Majoris

Canis Major

VY Canis Majoris

UW Canis Majoris

NGC 2362

Sirius

Caldwell catalogue

List of open clusters

Melotte catalogue

Herschel 400 Catalogue

Collinder catalogue

IAU designated constellations

List of brightest natural objects in the sky

List of stars for navigation

List of Arabic star names

Gamma Cassiopeiae variable

Gamma Centauri

List of largest stars

YZ Canis Minoris

List of supernova candidates

List of Chinese star names

Gliese 412

Water

Sigma Draconis