Tau1 Arietis - Misplaced Pages

Binary star system in the constellation Aries For other stars with this Bayer designation, see τ Arietis.

τ Arietis
Observation data Epoch J2000 Equinox J2000
Location of τ Arietis (circled)
Constellation	Aries
Right ascension	03 21 13.62462
Declination	+21° 08′ 49.4390″
Apparent magnitude (V)	5.27
Characteristics
Spectral type	B5 IV
U−B color index	−0.53
B−V color index	−0.06
Astrometry

Radial velocity (R_v)	+14 km/s
Proper motion (μ)	RA: +25.651 mas/yr Dec.: −19.850 mas/yr
Parallax (π)	6.1786 ± 0.2066 mas
Distance	530 ± 20 ly (162 ± 5 pc)
Absolute magnitude (M_V)	−0.66

Details

Mass	5.0±0.1 `M`_☉
Radius	4.45 `R`_☉
Luminosity	234 `L`_☉
Surface gravity (log g)	3.68 cgs
Temperature	12,606 K
Metallicity	−0.63 dex
Rotational velocity (v sin i)	30 km/s
Age	54.8±5.4 Myr

Other designations
τ Ari, 61 Arietis, BD+20 543, FK5 1094, HD 20756, HIP 15627, HR 1005, SAO 75886.
Database references
SIMBAD	data

Tau Arietis, Latinized from τ Arietis, is the Bayer designation for a triple star system in the northern constellation of Aries. Based upon an annual parallax shift of 6.1786 mas, it is approximately 530 light-years (162 parsecs) distant from Earth. The combined apparent visual magnitude is 5.27, making it faintly visible to the naked eye.

A light curve for Tau Arietis, plotted from *TESS* data

The Tau Arietis system contains three stars. The inner pair form an eclipsing binary system, with the brightness of the pair decreasing by 0.06 in magnitude during an eclipse of the primary. Its period is 2.20356 days. The third component is located at an angular separation of 0.810 arcseconds and has a magnitude of 8.17. The primary component is a subgiant star with a stellar classification of B5 IV. It has five times the mass of the Sun with about four times the Sun's radius.

This system is a member of the Cas-Tau OB association of stars that share a common motion through space.

References

^ 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.
^ Crawford, D. L.; Barnes, J. V.; Golson, J. C. (1971), "Four-color, H-beta, and UBV photometry for bright B-type stars in the northern hemisphere", The Astronomical Journal, 76: 1058, Bibcode:1971AJ.....76.1058C, doi:10.1086/111220.
^ Lesh, Janet Rountree (December 1968), "The Kinematics of the Gould Belt: an Expanding Group?", Astrophysical Journal Supplement, 17: 371, Bibcode:1968ApJS...17..371L, doi:10.1086/190179.
Evans, D. S. (June 20–24, 1966), "The Revision of the General Catalogue of Radial Velocities", in Batten, Alan Henry; Heard, John Frederick (eds.), Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30, vol. 30, University of Toronto: International Astronomical Union, p. 57, Bibcode:1967IAUS...30...57E.
^ 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.
^ Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society, 410 (1): 190–200, arXiv:1007.4883, Bibcode:2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x, S2CID 118629873.
Abt, Helmut A.; Levato, Hugo; Grosso, Monica (July 2002), "Rotational Velocities of B Stars", The Astrophysical Journal, 573 (1): 359–365, Bibcode:2002ApJ...573..359A, doi:10.1086/340590.
"tau01 Ari", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved 2012-08-11.
^ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
MAST: Barbara A. Mikulski Archive for Space Telescopes, Space Telescope Science Institute, retrieved 8 December 2021.
Malkov, O. Yu.; et al. (February 2006), "A catalogue of eclipsing variables", Astronomy and Astrophysics, 446 (2): 785–789, Bibcode:2006A&A...446..785M, doi:10.1051/0004-6361:20053137, hdl:10995/73280.
"tau 1 Ari", The International Variable Star Index, AAVSO, retrieved 17 July 2022.
de Zeeuw, P. T.; et al. (January 1999), "A HIPPARCOS Census of the Nearby OB Associations", The Astronomical Journal, 117 (1): 354–399, arXiv:astro-ph/9809227, Bibcode:1999AJ....117..354D, doi:10.1086/300682, S2CID 16098861.

External links

Constellation of Aries

Stars

Bayer	α (Hamal) β (Sheratan) γ (Mesarthim) δ (Botein) ε ζ η θ ι κ λ μ ν ξ ο π ρ ρ ρ σ τ τ
Flamsteed	1 4 7 10 11 14 15 16 19 20 21 23 26 27 29 30 31 33 35 36 38 39 (Lilii Borea) 40 41 (Bharani) 47 49 50 51 52 53 54 55 56 59 60 62 64 65 66 54 Cet 85 Cet
Variable	TZ UX VZ (16 Tri)
HR	577 728 803 952 999
HD	12661 20367
Other	BD+20°307 HIP 14810 HAT-P-25 Teegarden's Star WASP-11/HAT-P-10 WD 0145+234

Exoplanets	α Arietis b HD 12661 b c HIP 14810 b c d Teegarden's Star b c WASP-11b/HAT-P-10b

Galaxies

NGC	677 680 691 694 695 716 765 770 772 781 803 817 820 821 871 877 900 901 903 904 918 935 938 972 990 992 1024 1134 1156
Other	1ES 0229+200 3C 79 4C +28.07 AO 0235+164 IC 167 IC 1801 PSO J0309+27 Segue 2 UGC 2140

Galaxy clusters	MS 0302+17

Astronomical events	GRB 060218