Theta Arietis

θ Arietis
	Location of θ Arietis (circled)
Observation data; Epoch J2000 Equinox J2000
Constellation	Aries
Right ascension	02h 18m 07.531s
Declination	+19° 54′ 04.17″
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)	+11.95±0.78 km/s
Proper motion (μ)	RA: −7.832 mas/yr ; Dec.: −3.654 mas/yr
Parallax (π)	7.2220±0.1043 mas
Distance	452 ± 7 ly ; (138 ± 2 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 [Fe/H]	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, is a binary star^[7] system in the northern constellation of Aries. Its name is a Bayer designation that is Latinised from θ Arietis, and abbreviated Theta Ari or θ Ari. This star is faintly visible to the naked eye with an apparent visual magnitude of 5.58.^[3] With an annual parallax shift of 7.22 mas,^[2] the distance to this star is an estimated 452 light-years (139 parsecs) with a 7-light-year margin of error. It is drifting further away from the Sun with a radial velocity of +12 km/s.^[2]

The primary, component A, is a white-hued, A-type main-sequence star with a stellar classification of A1 Vn.^[4] 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.^[6]

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]

References

^ ^a ^b ^c 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. XHIP record for this object at VizieR.
^ ^a ^b ^c ^d ^e ^f ^g Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
^ ^a ^b 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.
^ ^a ^b 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.
^ ^a ^b 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.
^ ^a ^b 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.
^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j 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.
^ ^a ^b 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

[Anderson2012-1] 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. XHIP record for this object at VizieR.

[Gaia_DR3-2] ^ ^a ^b ^c ^d ^e ^f ^g Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.

[scfs-3] 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.

[aj74_375-4] 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.

[aa19_229-5] 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_et_al_2005-6] 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.

[Gullikson_et_al_2016-7] ^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j 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_Royer_2012-8] 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.

[aaa367_521-9] 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.

[aaa463_2_671-10] 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.

[SIMBAD-11] "* tet Ari", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved 2012-08-06.

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Theta Arietis

References

External links

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