Sirius A / B

The position of Sirius (circled).
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Canis Major
Pronunciation /ˈsɪriəs/
Right ascension 06
Declination −16° 42′ 58.017″
Apparent magnitude (V) −1.46 (A)
Characteristics
Spectral type A1V (A)
U−B color index −0.05 (A)
B−V color index 0.01 (A)
Astrometry
Radial velocity (Rv) −7.6 km/s
Proper motion (μ) RA: −546.05 mas/yr
Parallax (π) 379.21 ± 1.58mas
Distance 8.60 ± 0.04 ly
(2.64 ± 0.01 pc)
Absolute magnitude (MV) 1.42 (A)
Orbit
Companion α CMa B
Period (P) 50.090 ± 0.055 yr
Semimajor axis (a) 7.50 ± 0.04"
Eccentricity (e) 0.5923 ± 0.0019
Inclination (i) 136.53 ± 0.43°
Longitude of the node (Ω) 44.57 ± 0.44°
Periastron epoch (T) 1894.130 ± 0.015
Argument of periastron (ω)
(secondary)
147.27 ± 0.54°
Details
α CMa A
Mass 2.02M
Radius 1.711R
Luminosity 25.4L
Surface gravity (log g) 4.33
Temperature 9,940K
Metallicity [Fe/H] 0.50dex
Rotation 16 km/s
Age 2–3 × 10 years
α CMa B
Mass 0.978M
Radius 0.0084 ± 3%R
Luminosity 0.026L
Surface gravity (log g) 8.57
Temperature 25,200K
Other designations
System: Dog Star, Aschere, Canicula, Al Shira, Sothis,

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Sirius, which is released under the Creative Commons Attribution-Share-Alike License 3.0