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Sigma1 Tauri

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Sigma1 Tauri
Location of σ1 Tauri (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Taurus
Right ascension 04h 39m 09.22247s[1]
Declination +15° 47′ 59.5345″[1]
Apparent magnitude (V) 5.07[2]
Characteristics
Spectral type A4m[3]
U−B color index 0.190[2]
B−V color index 0.146[2]
Astrometry
Radial velocity (Rv)+26.1±10.0[4] km/s
Proper motion (μ) RA: +41.91[1] mas/yr
Dec.: −66.88[1] mas/yr
Parallax (π)22.18±0.93 mas[1]
Distance147 ± 6 ly
(45 ± 2 pc)
Absolute magnitude (MV)1.73[2]
Orbit[5]
Primaryσ1 Tau A
Companionσ1 Tau B
Period (P)38.951 d
Eccentricity (e)0.15
Longitude of the node (Ω)82°
Periastron epoch (T)2443094.319 JD
Semi-amplitude (K1)
(primary)		7.9 km/s
Details
Mass1.94[2] M☉
Luminosity14.7[6] L☉
Surface gravity (log g)4.08[2] cgs
Temperature8,470[2] K
Rotational velocity (v sin i)56.5±7.1[7] km/s
Other designations
91 Tauri, BD+15°665, HD 29479, HIP 21673, HR 1478, SAO 94051, WDS J04393+1555B[8]
Database references
SIMBADdata

Sigma1 Tauri (σ1 Tauri) is the Bayer designation for a white-hued star in the zodiac constellation of Taurus. It has an apparent visual magnitude of +5.07,[2] which indicates it is visible to the naked eye. Based upon parallax measurements, σ1 Tauri is about 147 light-years from the Sun.

σ1 Tauri is a single-lined spectroscopic binary star system with an orbital period of 38.951 days and an eccentricity of 0.15. The visible component is an Am star with a stellar classification of A4m,[3] indicating it is chemically peculiar A-type star. It is spinning with a projected rotational velocity of 56.5 km/s.[7] The star has 1.9[2] times the mass of the Sun and is radiating 14.7[6] times the Sun's luminosity from its photosphere at an effective temperature of 8,470 K.[2] Although it lies in the general direction of the Hyades cluster, based on parallax measurements it has been excluded from the list of candidate members.[2]

References

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  1. ^ a b c d e van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
  2. ^ a b c d e f g h i j k Iliev, I. Kh.; et al. (August 2006), "Abundance analysis of Am binaries and search for tidally driven abundance anomalies - II. HD861, HD18778, HD20320, HD29479, HD96528 and HD108651", Monthly Notices of the Royal Astronomical Society, 370 (2): 819–827, Bibcode:2006MNRAS.370..819I, doi:10.1111/j.1365-2966.2006.10513.x, S2CID 56133360.
  3. ^ a b Cowley, A.; et al. (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.
  4. ^ de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, S2CID 59451347, A61.
  5. ^ Pourbaix, D.; et al. (2004), "SB9: The ninth catalogue of spectroscopic binary orbits", Astronomy and Astrophysics, 424 (2): 727–732, arXiv:astro-ph/0406573, Bibcode:2004A&A...424..727P, doi:10.1051/0004-6361:20041213, S2CID 119387088.
  6. ^ a b McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–57, arXiv:1208.2037, Bibcode:2012MNRAS.427..343M, doi:10.1111/j.1365-2966.2012.21873.x, S2CID 118665352.
  7. ^ a b Paunzen, E.; et al. (February 2013), "A photometric study of chemically peculiar stars with the STEREO satellites - II. Non-magnetic chemically peculiar stars", Monthly Notices of the Royal Astronomical Society, 429 (1): 119–125, arXiv:1211.1535, Bibcode:2013MNRAS.429..119P, doi:10.1093/mnras/sts318, S2CID 119231581.
  8. ^ "sig01 Tau". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-08-06.{{cite web}}: CS1 maint: postscript (link)
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