Location of θ Arietis (circled) | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aries |
| Right ascension | 02 18 07.53022 |
| Declination | +19° 54′ 04.1717″ |
| Apparent magnitude (V) | 5.58 |
| Characteristics | |
| Spectral type | A1 Vn |
| U−B color index | +0.02 |
| B−V color index | +0.01 |
| Variable type | Constant |
| Astrometry | |
| Radial velocity (Rv) | +6.0 km/s |
| Proper motion (μ) | RA: −7.491 mas/yr Dec.: −3.978 mas/yr |
| Parallax (π) | 7.6084 ± 0.1763 mas |
| Distance | 429 ± 10 ly (131 ± 3 pc) |
| Absolute magnitude (MV) | −0.10 |
| Details | |
| A | |
| Mass | 2.10+0.37 −0.31 M☉ 2.94±0.06 M☉ |
| Radius | 1.9–2.5 R☉ |
| Luminosity | 106 L☉ |
| Surface gravity (log g) | 4.00±0.25 cgs |
| Temperature | 9,500±1,000 K |
| Rotational velocity (v sin i) | 186 km/s |
| Age | 107+286 −93 Myr |
| B | |
| Mass | 1.0+0.02 −0.04 M☉ |
| Temperature | 5,578±109 K |
| Metallicity | 0.0 dex |
| Rotational velocity (v sin i) | 5 km/s |
| Other designations | |
| θ Ari, 22 Arietis, BD+19 340, FK5 81, HD 14191, HIP 10732, HR 669, SAO 92877 | |
| Database references | |
| SIMBAD | data |
Theta Arietis, Latinised from θ Arietis, is the Bayer designation for a binary star system in the northern constellation of Aries. It is faintly visible to the naked eye with an apparent visual magnitude of 5.58. With an annual parallax shift of 7.61 mas, 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.
The primary, component A, is a white-hued, A-type main-sequence star with a stellar classification of A1 Vn. It is spinning at a rapid pace as shown by the projected rotational velocity of 186 km/s. 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.
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.
References
- ^ Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ Wielen, R.; et al. (1999), "Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions", Veroeffentlichungen des Astronomischen Rechen-Instituts Heidelberg, 35 (35), Astronomisches Rechen-Institut Heidelberg: 1, Bibcode:1999VeARI..35....1W.
- ^ Cowley, A.; et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal, 74: 375–406, Bibcode:1969AJ.....74..375C, doi:10.1086/110819.
- ^ Rybka, E. (1969), "The corrected magnitudes and colours of 278 stars near S.A. 1-139 in the UBV system", Acta Astronomica, 19: 229, Bibcode:1969AcA....19..229R.
- ^ Neiner, C.; et al. (February 2005), "The Identification of New Be Stars in GAUDI", The Astrophysical Journal Supplement Series, 156 (2): 237–243, Bibcode:2005ApJS..156..237N, doi:10.1086/426670, S2CID 123143757.
- ^ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
- ^ Gullikson, Kevin; et al. (August 2016), "The Close Companion Mass-ratio Distribution of Intermediate-mass Stars", The Astronomical Journal, 152 (2): 13, arXiv:1604.06456, Bibcode:2016AJ....152...40G, doi:10.3847/0004-6256/152/2/40, S2CID 119179065, 40.
- Zorec, J.; Royer, F. (2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy & Astrophysics, 537: A120, arXiv:1201.2052, Bibcode:2012A&A...537A.120Z, doi:10.1051/0004-6361/201117691, S2CID 55586789.
- Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics", Astronomy and Astrophysics, 367 (2): 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451, S2CID 425754.
- ^ Royer, F.; Zorec, J.; Gómez, A. E. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics, 463 (2): 671–682, arXiv:astro-ph/0610785, Bibcode:2007A&A...463..671R, doi:10.1051/0004-6361:20065224, S2CID 18475298.
- "* tet Ari", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved 2012-08-06.
External links
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