Sirius Data

 

Sirius

 

Names:

            The Dog Star, Alpha Canis Majoris, 9 CMa, HR 2491

            HD 48915, BD -16° 1591, ADS 5423, AC 1,LHS 219

Position:

            α2000 = 06h 45m 08.9173s

δ2000 = -16° 42' 58.017" (epoch 2000)

Proper Motion:

            μα= 0.5461"/yr

 μδ = -1.2231"/yr    

            r = 1.3395"/yr

q = 204.0576°

Distance:

            2.6314 pc, 8.553 light years, 8.120x1013 km

Parallax (π):

            380.023 ± 1.283 milli-arc seconds       

Radial Velocity:

            -8.7 km/s

 

Orbit

 

Period:

            50.075 ± 0.103 years

Epoch:

            1994.352 ± 037 (last periapse passage)

a:

            7.50 ± 0.03"  19.82 AU

e:

            0.59657 ± 0.00130  (Eccentricity)

i:

            138.4376° ± 0.298° (Inclination)

Ω:

            150.334° ± 0.348° (Longitude of Ascending Node)

ω:

            45.685° ± 0.240°  (Argument of Periapse)

 

 

Sirius A

 

V Magnitude:

            -1.46

Spectral Type:

            A1V

Mass:

            2.02 ± 0.03 M Sun

Radius:

            1.712 ± 0.00025 R Sun

Mean Density:

            0.568 grams/cm3

Luminosity:

            25.4 ±1.3 LSun

Temperature:

            10,500 K

Gravity:

            8.556 ± 0.010 (log of Surface Gravity)

Age:

            238 ± 13 Million years (Main Sequence)

 

 

 

Sirius B

 

WD0642-162

V Magnitude:

            +8.44

Spectral Type:

            DA2

Mass:

            1.00 ± 0.01 M Sun

Radius:

            0.0084 ± 0.00025 R Sun (5840 km)

Mean Density:

            2.38x106 grams/cm3

Central Density:

            32.36x106 grams/cm3

Temperature:

            25,193 ± 37K

Gravity:

            8.556 0.010 (log of Surface Gravity in cgs units)

Vgr:

             +80.42 ± 4.83 km/s (Gravitational Redshift)

Age:

            123 Million years (White Dwarf Cooling Age)

Progenitor Mass:

            5.056 M Sun (±7%)

 

 

 

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