41 Tauri

41 Tauri

41 Tauri is the brightest star on the right of the molecular cloud LBN 777.
Observation data
Epoch J2000.0      Equinox ICRS
Constellation Taurus
Right ascension 04h 06m 36.413s
Declination +27° 35′ 59.64″
Apparent magnitude (V) 5.19
Characteristics
Evolutionary stage main sequence
Spectral type B9 p Si
U−B color index −0.47
B−V color index −0.12
Variable type α2 CVn
Astrometry
Radial velocity (Rv)−2.0 km/s
Proper motion (μ) RA: +21.153 mas/yr
Dec.: −51.792 mas/yr
Parallax (π)8.0667±0.1063 mas
Distance404 ± 5 ly
(124 ± 2 pc)
Orbit
Period (P)7.2274 d
Eccentricity (e)0.18
Semi-amplitude (K1)
(primary)		16.60 km/s
Details
Mass2.9 M☉
Radius3.54 R☉
Luminosity190 L☉
Surface gravity (log g)3.87 cgs
Temperature12,600 K
Metallicity [Fe/H]0.43 dex
Rotational velocity (v sin i)23 km/s
Age146 Myr
Other designations
GS Tau, BD+27°633, HD 25823, HIP 19171, HR 1268, SAO 76455
Database references
SIMBADdata

41 Tauri is a single-lined spectroscopic binary system in the zodiacal constellation of Taurus; 41 Tauri is its Flamsteed designation. The star has a visual magnitude of 5.19, making it visible to the naked eye from brighter suburban skies (according to the Bortle scale). Parallax measurements put it at a distance of roughly 404 light years from the Sun.

A light curve for GS Tauri (41 Tauri), plotted from TESS data

This is a chemically peculiar star and was first classified as a silicon star by American astronomer William Morgan in 1933. The stellar spectrum displays an overabundance of heavier elements; particularly silicon and gallium. These abundances may be caused by the magnetic field of the star, which produces concentrations of the observed elements in the outer atmosphere. In 1962, Karl D. Rakos announced that 41 Tauri is a variable star based on observations made in 1960 and 1961. It is an α² Canum Venaticorum-type variable star, ranging in magnitude from 5.15 down to 5.22. These variations are likely due to large spots or rings on the side of the star being observed.

The star and its companion orbit each other closely with a period of a week and an eccentricity of 0.18. The rotation period of the primary star has become locked to its orbit, so that one face is always pointed toward its companion. The abundance of gallium and silicon varies in a sinusoidal pattern that matches this period.

The primary has around 2.9 times the mass of the Sun, 3.5 times the Sun's radius, and is emitting 190 times the luminosity of the Sun. The effective temperature of the star's photosphere is 12,600 K, giving it the blue-white hue of a B-type star.

References

  1. 1 2 3 4 5 6 7 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.
  2. 1 2 3 4 Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data. SIMBAD, Bibcode:1986EgUBV........0M.
  3. ↑ 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.
  4. 1 2 Kukarkin, B. V.; et al. (1971), General Catalogue of Variable Stars (3rd ed.), Bibcode:1971GCVS3.C......0K.
  5. ↑ Wilson, R. E. (1953), "General Catalogue of Stellar Radial Velocities", Carnegie Institute Washington D.C. Publication, Washington, D. C.: Carnegie Institute of Washington., Bibcode:1953GCRV..C......0W.
  6. 1 2 3 Ducati, J. R.; et al. (January 2011), "The mass ratio and initial mass functions in spectroscopic binaries", Astronomy and Astrophysics, 525: 9, Bibcode:2011A&A...525A..26D, doi:10.1051/0004-6361/200913895, hdl:10183/99264, A26.
  7. 1 2 Shulyak, D.; et al. (September 2014), "Interferometry of chemically peculiar stars: theoretical predictions versus modern observing facilities", Monthly Notices of the Royal Astronomical Society, 443 (2): 1629–1642, arXiv:1406.6093, Bibcode:2014MNRAS.443.1629S, doi:10.1093/mnras/stu1259.
  8. 1 2 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.
  9. 1 2 3 4 5 Bolcal, C.; et al. (December 1987), "A model atmosphere analysis of HD 25823", Astrophysics and Space Science, 139 (2): 295–304, Bibcode:1987Ap&SS.139..295B, doi:10.1007/BF00644358, S2CID 121253643.
  10. ↑ Freire Ferrero, R.; et al. (February 2012), "High Ionization Species in the Nearby Interstellar Medium from an Exhaustive Analysis of the IUE INES Database", The Astronomical Journal, 143 (2): 38, Bibcode:2012AJ....143...28F, doi:10.1088/0004-6256/143/2/28, 28.
  11. ↑ Gontcharov, G. A. (2012), "Dependence of kinematics on the age of stars in the solar neighborhood", Astronomy Letters, 38 (12): 771–782, arXiv:1606.08814, Bibcode:2012AstL...38..771G, doi:10.1134/S1063773712120031, S2CID 118345778.
  12. ↑ "41 Tau", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved 2015-11-09.
  13. ↑ MAST: Barbara A. Mikulski Archive for Space Telescopes, Space Telescope Science Institute, retrieved 8 December 2021.
  14. 1 2 Artru, M.-C.; Freire-Ferrero, R. (September 1988), "Line variations in the ultra-violet spectrum of the Ap-Si star HD 25823", Astronomy and Astrophysics, 203 (1): 111–116, Bibcode:1988A&A...203..111A.
  15. ↑ Rakos, Karl D. (1962). "Photoelectric investigation of magnetic and spectrum variable stars". Bulletin/Lowell Observatory. 5 (117): 227–256. Bibcode:1962LowOB...5..227R. Retrieved 7 September 2025.
  16. ↑ Mantegazza, L.; Poretti, E.; Riboni, E. (September 1990). "The Changing Light Curve of the Ap Star 41 Tauri" (PDF). Information Bulletin on Variable Stars. 3518: 1–4. Bibcode:1990IBVS.3518....1M. Retrieved 7 September 2025.
  17. ↑ "The Colour of Stars", Australia Telescope, Outreach and Education, Commonwealth Scientific and Industrial Research Organisation, December 21, 2004, archived from the original on March 18, 2012, retrieved 2012-01-16.