Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Aries |
Right ascension | 02h 18m 07.53022s [1] |
Declination | +19° 54′ 04.1717″ [1] |
Apparent magnitude (V) | 5.58 [2] |
Characteristics | |
Spectral type | A1 Vn [3] |
U−B color index | +0.02 [4] |
B−V color index | +0.01 [4] |
Variable type | Constant [5] |
Astrometry | |
Radial velocity (Rv) | +6.0 [2] km/s |
Proper motion (μ) |
RA: −7.491
[1]
mas/
yr Dec.: −3.978 [1] mas/ yr |
Parallax (π) | 7.6084 ± 0.1763 mas [1] |
Distance | 429 ± 10
ly (131 ± 3 pc) |
Absolute magnitude (MV) | −0.10 [6] |
Details | |
A | |
Mass | 2.10+0.37 −0.31 M☉ [7] 2.94±0.06 [8] M☉ |
Radius | 1.9–2.5 [9] R☉ |
Luminosity | 106 [6] L☉ |
Surface gravity (log g) | 4.00±0.25 [7] cgs |
Temperature | 9,500±1,000 [7] K |
Rotational velocity (v sin i) | 186 [10] km/s |
Age | 107+286 −93 [7] Myr |
B | |
Mass | 1.0+0.02 −0.04 [7] M☉ |
Temperature | 5,578±109 [7] K |
Metallicity [Fe/H] | 0.0 [7] dex |
Rotational velocity (v sin i) | 5 [7] km/s |
Other designations | |
Database references | |
SIMBAD | data |
Theta Arietis, Latinised from θ Arietis, is the Bayer designation for a binary star [7] system in the northern constellation of Aries. It is faintly visible to the naked eye with an apparent visual magnitude of 5.58. [2] With an annual parallax shift of 7.61 mas, [1] the distance to this star is an estimated 429 light-years (132 parsecs) with a 10-light-year margin of error. It is drifting further away with a radial velocity of +6 km/s. [2]
The primary, component A, is a white-hued, A-type main-sequence star with a stellar classification of A1 Vn. [3] It is spinning at a rapid pace as shown by the projected rotational velocity of 186 km/s. [10] This is causing the "nebulous" appearance of the absorption lines indicated by the 'n' suffix in the classification. In 2005, C. Neiner and associates classified this as a Be star because is displays emission features in the hydrogen Balmer lines. [5]
In 2016, a solar-mass companion was reported in close orbit around this star, based on observations using adaptive optics with the Gemini North Telescope. [7]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Aries |
Right ascension | 02h 18m 07.53022s [1] |
Declination | +19° 54′ 04.1717″ [1] |
Apparent magnitude (V) | 5.58 [2] |
Characteristics | |
Spectral type | A1 Vn [3] |
U−B color index | +0.02 [4] |
B−V color index | +0.01 [4] |
Variable type | Constant [5] |
Astrometry | |
Radial velocity (Rv) | +6.0 [2] km/s |
Proper motion (μ) |
RA: −7.491
[1]
mas/
yr Dec.: −3.978 [1] mas/ yr |
Parallax (π) | 7.6084 ± 0.1763 mas [1] |
Distance | 429 ± 10
ly (131 ± 3 pc) |
Absolute magnitude (MV) | −0.10 [6] |
Details | |
A | |
Mass | 2.10+0.37 −0.31 M☉ [7] 2.94±0.06 [8] M☉ |
Radius | 1.9–2.5 [9] R☉ |
Luminosity | 106 [6] L☉ |
Surface gravity (log g) | 4.00±0.25 [7] cgs |
Temperature | 9,500±1,000 [7] K |
Rotational velocity (v sin i) | 186 [10] km/s |
Age | 107+286 −93 [7] Myr |
B | |
Mass | 1.0+0.02 −0.04 [7] M☉ |
Temperature | 5,578±109 [7] K |
Metallicity [Fe/H] | 0.0 [7] dex |
Rotational velocity (v sin i) | 5 [7] km/s |
Other designations | |
Database references | |
SIMBAD | data |
Theta Arietis, Latinised from θ Arietis, is the Bayer designation for a binary star [7] system in the northern constellation of Aries. It is faintly visible to the naked eye with an apparent visual magnitude of 5.58. [2] With an annual parallax shift of 7.61 mas, [1] the distance to this star is an estimated 429 light-years (132 parsecs) with a 10-light-year margin of error. It is drifting further away with a radial velocity of +6 km/s. [2]
The primary, component A, is a white-hued, A-type main-sequence star with a stellar classification of A1 Vn. [3] It is spinning at a rapid pace as shown by the projected rotational velocity of 186 km/s. [10] This is causing the "nebulous" appearance of the absorption lines indicated by the 'n' suffix in the classification. In 2005, C. Neiner and associates classified this as a Be star because is displays emission features in the hydrogen Balmer lines. [5]
In 2016, a solar-mass companion was reported in close orbit around this star, based on observations using adaptive optics with the Gemini North Telescope. [7]