Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
---|---|
Constellation | Aries |
Right ascension | 02h 51m 29.58618s [1] |
Declination | +15° 04′ 55.4438″ [1] |
Apparent magnitude (V) | +5.52 [2] |
Characteristics | |
Spectral type | B7 V [3] |
U−B color index | –0.43 [2] |
B−V color index | –0.09 [2] |
Astrometry | |
Radial velocity (Rv) | +17.0 [4] km/s |
Proper motion (μ) |
RA: +29.843
[1]
mas/
yr Dec.: –24.661 [1] mas/ yr |
Parallax (π) | 6.8952 ± 0.2164 mas [1] |
Distance | 470 ± 10
ly (145 ± 5 pc) |
Absolute magnitude (MV) | −0.38 [5] |
Details | |
A | |
Mass | 3.84±0.08 [6] M☉ |
Radius | 3 [7] R☉ |
Luminosity | 301 [6] L☉ |
Surface gravity (log g) | 4.0±0.25 [8] cgs |
Temperature | 13,121 [6] K |
Rotational velocity (v sin i) | 165 [6] km/s |
Age | 36+57 −27 [8] Myr |
B | |
Mass | 1.0–1.2 [8] M☉ |
Temperature | 5,524±150 [8] K |
Metallicity [Fe/H] | −0.5 [8] dex |
Rotational velocity (v sin i) | 5 km/s |
Other designations | |
Database references | |
SIMBAD | data |
Sigma Arietis, Latinized from σ Arietis, is the Bayer designation for a star in the northern constellation of Aries. It has an apparent visual magnitude of +5.52, [2] which is bright enough for the star to be seen with the naked eye from dark suburban skies. The star is located at a distance of approximately 470 light-years (140 parsecs) from the Sun based on parallax, and is drifting further away with a radial velocity of +17 km/s. [4] On November 20, 1952, it was observed being occulted by the planet Jupiter. [10]
Sigma Arietis is a B-type main sequence star with a stellar classification of B7 V. [3] This is a large star with three [7] times the radius of the Sun and 3.8 [6] times the Sun's mass. It shines around 301 [6] times as brightly as the helium and oxeygen, with this energy being radiated into space from its outer atmosphere at a scorching hot effective temperature of 13,121 K. [6] It is this heat that gives the star the blue-white hue of a B-type star. Sigma Arietis is spinning at a rapid clip, with a projected rotational velocity of 165 km/s. [6] It is a probable member of the Cas-Tau OB association of stars that share a common motion through space. [11]
In 2016, a stellar companion was reported based on observations using adaptive optics with the Gemini North Telescope. [8]
{{
cite web}}
: CS1 maint: postscript (
link)
Observation data Epoch J2000.0 Equinox J2000.0 ( ICRS) | |
---|---|
Constellation | Aries |
Right ascension | 02h 51m 29.58618s [1] |
Declination | +15° 04′ 55.4438″ [1] |
Apparent magnitude (V) | +5.52 [2] |
Characteristics | |
Spectral type | B7 V [3] |
U−B color index | –0.43 [2] |
B−V color index | –0.09 [2] |
Astrometry | |
Radial velocity (Rv) | +17.0 [4] km/s |
Proper motion (μ) |
RA: +29.843
[1]
mas/
yr Dec.: –24.661 [1] mas/ yr |
Parallax (π) | 6.8952 ± 0.2164 mas [1] |
Distance | 470 ± 10
ly (145 ± 5 pc) |
Absolute magnitude (MV) | −0.38 [5] |
Details | |
A | |
Mass | 3.84±0.08 [6] M☉ |
Radius | 3 [7] R☉ |
Luminosity | 301 [6] L☉ |
Surface gravity (log g) | 4.0±0.25 [8] cgs |
Temperature | 13,121 [6] K |
Rotational velocity (v sin i) | 165 [6] km/s |
Age | 36+57 −27 [8] Myr |
B | |
Mass | 1.0–1.2 [8] M☉ |
Temperature | 5,524±150 [8] K |
Metallicity [Fe/H] | −0.5 [8] dex |
Rotational velocity (v sin i) | 5 km/s |
Other designations | |
Database references | |
SIMBAD | data |
Sigma Arietis, Latinized from σ Arietis, is the Bayer designation for a star in the northern constellation of Aries. It has an apparent visual magnitude of +5.52, [2] which is bright enough for the star to be seen with the naked eye from dark suburban skies. The star is located at a distance of approximately 470 light-years (140 parsecs) from the Sun based on parallax, and is drifting further away with a radial velocity of +17 km/s. [4] On November 20, 1952, it was observed being occulted by the planet Jupiter. [10]
Sigma Arietis is a B-type main sequence star with a stellar classification of B7 V. [3] This is a large star with three [7] times the radius of the Sun and 3.8 [6] times the Sun's mass. It shines around 301 [6] times as brightly as the helium and oxeygen, with this energy being radiated into space from its outer atmosphere at a scorching hot effective temperature of 13,121 K. [6] It is this heat that gives the star the blue-white hue of a B-type star. Sigma Arietis is spinning at a rapid clip, with a projected rotational velocity of 165 km/s. [6] It is a probable member of the Cas-Tau OB association of stars that share a common motion through space. [11]
In 2016, a stellar companion was reported based on observations using adaptive optics with the Gemini North Telescope. [8]
{{
cite web}}
: CS1 maint: postscript (
link)