Sigma1 Tauri

Sigma1 Tauri
	Location of σ1 Tauri (circled)
Observation data; Epoch J2000.0 Equinox J2000.0 (ICRS)
Constellation	Taurus
Right ascension	04h 39m 09.22247s
Declination	+15° 47′ 59.5345″
Apparent magnitude (V)	5.07
Characteristics
Spectral type	A4m
U−B color index	0.190
B−V color index	0.146
Astrometry
Radial velocity (Rv)	+26.1±10.0 km/s
Proper motion (μ)	RA: +41.91 mas/yr ; Dec.: −66.88 mas/yr
Parallax (π)	22.18±0.93 mas
Distance	147 ± 6 ly ; (45 ± 2 pc)
Absolute magnitude (MV)	1.73
Orbit
Primary	σ1 Tau A
Companion	σ1 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
Mass	1.94 M☉
Luminosity	14.7 L☉
Surface gravity (log g)	4.08 cgs
Temperature	8,470 K
Rotational velocity (v sin i)	56.5±7.1 km/s
Other designations
	91 Tauri, BD+15°665, HD 29479, HIP 21673, HR 1478, SAO 94051, WDS J04393+1555B
Database references
SIMBAD	data

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

^ ^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.
^ ^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.
^ ^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.
^ 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.
^ 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.
^ ^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.
^ ^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.
^ "sig01 Tau". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-08-06.{{cite web}}: CS1 maint: postscript (link)

[vanLeeuwen2007-1] 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.

[Iliev2006-2] ^ ^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.

[Cowley1969-3] 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.

[deBruijne2012-4] 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.

[Pourbaiz2004-5] 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.

[Mcdonald2012-6] 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.

[Paunzen2013-7] 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.

[SIMBAD_01-8] "sig01 Tau". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-08-06.{{cite web}}: CS1 maint: postscript (link)

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Sigma1 Tauri

References

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