Astronomy:Tau Andromedae
Observation data Equinox J2000.0]] (ICRS) | |
---|---|
Constellation | Andromeda |
Right ascension | 01h 40m 34.81619s[1] |
Declination | +40° 34′ 37.3397″[1] |
Apparent magnitude (V) | +4.94[2] |
Characteristics | |
Spectral type | B5 III[3] |
U−B color index | −0.41[2] |
B−V color index | −0.09[2] |
Astrometry | |
Radial velocity (Rv) | −13.9±2.6[4] km/s |
Proper motion (μ) | RA: 17.889(178)[1] mas/yr Dec.: −20.981(95)[1] mas/yr |
Parallax (π) | 4.7804 ± 0.1304[1] mas |
Distance | 680 ± 20 ly (209 ± 6 pc) |
Details | |
Luminosity | 851[5] L☉ |
Surface gravity (log g) | 3.357±0.020[6] cgs |
Temperature | 12,680±100[6] K |
Rotational velocity (v sin i) | 74±13[6] km/s |
Age | 217[7] Myr |
Other designations | |
Database references | |
SIMBAD | data |
Tau Andromedae, Latinized from τ Andromedae, is the Bayer designation for a single[9] star in the northern constellation of Andromeda. It has an apparent visual magnitude of +4.94,[2] which is bright enough to be viewed from dark suburban skies. From parallax measurements made during the Gaia mission, the distance to this star can be estimated as roughly 680 light-years (210 parsecs) from Earth. The brightness of this star is diminished by 0.24 in magnitude due to extinction caused by intervening gas and dust.[3] It is drifting closer to the Sun with a radial velocity of −14 km/s.[4]
The spectrum of this star matches a stellar classification of B5 III,[3] with the luminosity class of III indicating that this is a giant star. It is radiating about 851 times the luminosity of the Sun[5] from its photosphere at an effective temperature of 12,670 K.[6] The star is an estimated 217[7] million years old and is spinning with a high projected rotational velocity of ~74 km/s.[6]
Naming
In Chinese, 天大將軍 (Tiān Dà Jiāng Jūn), meaning Heaven's Great General, refers to an asterism consisting of τ Andromedae, γ Andromedae, φ Persei, 51 Andromedae, 49 Andromedae, χ Andromedae, υ Andromedae, 56 Andromedae, β Trianguli, γ Trianguli and δ Trianguli. Consequently, the Chinese name for τ Andromedae itself is 天大將軍七 (Tiān Dà Jiāng Jūn qī, English: the Seventh Star of Heaven's Great General.).[10]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Brown, A. G. A. (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics 649: A1. doi:10.1051/0004-6361/202039657. Bibcode: 2021A&A...649A...1G. Gaia EDR3 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 2.3 Johnson, H. L. et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory 4 (99): 99, Bibcode: 1966CoLPL...4...99J.
- ↑ 3.0 3.1 3.2 van Belle, Gerard T.; von Braun, Kaspar (April 2009), "Directly Determined Linear Radii and Effective Temperatures of Exoplanet Host Stars", The Astrophysical Journal 694 (2): 1085–1098, doi:10.1088/0004-637X/694/2/1085, Bibcode: 2009ApJ...694.1085V.
- ↑ 4.0 4.1 Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system", Astronomy Letters 32 (11): 759–771, doi:10.1134/S1063773706110065, Bibcode: 2006AstL...32..759G.
- ↑ 5.0 5.1 van Belle, G. T. et al. (May 2008), "The Palomar Testbed Interferometer Calibrator Catalog", The Astrophysical Journal Supplement Series 176 (1): 276–292, doi:10.1086/526548, Bibcode: 2008ApJS..176..276V.
- ↑ 6.0 6.1 6.2 6.3 6.4 Huang, Wenjin et al. (October 2010), "A Stellar Rotation Census of B Stars: From ZAMS to TAMS" (in en), Astrophysical Journal 722 (1): 605–619, doi:10.1088/0004-637X/722/1/605, ISSN 0004-637X, Bibcode: 2010ApJ...722..605H.
- ↑ 7.0 7.1 Gontcharov, G. A. (November 2012), "Spatial distribution and kinematics of OB stars", Astronomy Letters 38 (11): 694–706, doi:10.1134/S1063773712110035, Bibcode: 2012AstL...38..694G.
- ↑ "* tau And". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=%2A+tau+And.
- ↑ 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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
- ↑ (in Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 10 日
External links
![]() | Original source: https://en.wikipedia.org/wiki/Tau Andromedae.
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