Zeta1 Lyrae

Zeta1 Lyrae
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Lyra
Right ascension 18h 44m 46.35735s[1]
Declination +37° 36′ 18.4171″[1]
Apparent magnitude (V) 4.37[2]
Characteristics
Spectral type A4m[3]
U−B color index +0.17[2]
B−V color index +0.18[2]
Astrometry
Proper motion (μ) RA: +29.04[1] mas/yr
Dec.: +27.03[1] mas/yr
Parallax (π)20.89 ± 0.17[1] mas
Distance156 ± 1 ly
(47.9 ± 0.4 pc)
Orbit[4]
Period (P)4.3 d
Eccentricity (e)0.01
Periastron epoch (T)2440000.723 JD
Argument of periastron (ω)
(secondary)		0.00°
Semi-amplitude (K1)
(primary)		51.6 km/s
Details
Mass2.36[5] M☉
Radius2.5[6] R☉
Luminosity31[7] L☉
Surface gravity (log g)3.7±0.1[8] cgs
Temperature7914±112[8] K
Metallicity [Fe/H]0.38±0.06[8] dex
Rotational velocity (v sin i)47[9] km/s
Age500[5] Myr
Other designations
ζ1 Lyr, 6 Lyr, BD+37° 3222, HD 173648, HIP 91971, HR 7056, SAO 67321.[10]
Database references
SIMBADdata

Zeta1 Lyrae (ζ1 Lyr) is a binary star in the northern constellation of Lyra. Based upon an annual parallax shift of 20.89 mas as seen from Earth,[1] the pair are located about 156 light years from the Sun. It is visible to the naked eye with an apparent visual magnitude of 4.37.[2]

This is a single-lined spectroscopic binary system with an orbital period of 4.3 days and a nearly circular orbit with an eccentricity of 0.01.[4] The primary, component A, is an Am star with a stellar classification of A4m.[3] It appears to be mildly variable, with a frequency of 0.65256 cycles per day and an amplitude of 0.0032 in magnitude.[11] The star has an estimated 2.36[5] times the mass of the Sun and around 2.5[6] times the Sun's radius. The position of this system is associated with an X-ray source with a luminosity of 571.6×1020 W.[12]

References

  1. 1 2 3 4 5 6 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, Bibcode:2007A&A...474..653V, arXiv:0708.1752 Freely accessible, doi:10.1051/0004-6361:20078357.
  2. 1 2 3 4 Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV data, SIMBAD, Bibcode:1986EgUBV........0M.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. 1 2 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 Pourbaix, D.; Tokovinin, A. A.; Batten, A. H.; Fekel, F. C.; Hartkopf, W. I.; et al. (2004), "SB9: The ninth catalogue of spectroscopic binary orbits", Astronomy & Astrophysics, 424 (2): 727, Bibcode:2004A&A...424..727P, arXiv:astro-ph/0406573 Freely accessible, doi:10.1051/0004-6361:20041213.
  5. 1 2 3 De Rosa, R. J.; et al. (2013), "The VAST Survey - III. The multiplicity of A-type stars within 75 pc", Monthly Notices of the Royal Astronomical Society, 437 (2): 1216, Bibcode:2014MNRAS.437.1216D, arXiv:1311.7141 Freely accessible, doi:10.1093/mnras/stt1932.
  6. 1 2 Pasinetti Fracassini, L. E.; Pastori, L.; Covino, S.; Pozzi, A. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics (3rd ed.), 367: 521–524, Bibcode:2001A&A...367..521P, arXiv:astro-ph/0012289 Freely accessible, doi:10.1051/0004-6361:20000451.
  7. ↑ McDonald, I.; et al. (2012). "Fundamental Parameters and Infrared Excesses of Hipparcos Stars". Monthly Notices of the Royal Astronomical Society. 427 (1): 343–57. Bibcode:2012MNRAS.427..343M. arXiv:1208.2037 Freely accessible. doi:10.1111/j.1365-2966.2012.21873.x.
  8. 1 2 3 Prugniel, Ph.; et al. (2011), "The atmospheric parameters and spectral interpolator for the MILES stars", Astronomy & Astrophysics, 531: A165, arXiv:1104.4952 Freely accessible, doi:10.1051/0004-6361/201116769.
  9. ↑ Royer, F.; et al. (October 2002), "Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i", Astronomy and Astrophysics, 393: 897−911, Bibcode:2002A&A...393..897R, arXiv:astro-ph/0205255 Freely accessible, doi:10.1051/0004-6361:20020943.
  10. ↑ "* zet01 Lyr". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-03-17.
  11. ↑ Koen, Chris; Eyer, Laurent (2002), "New periodic variables from the Hipparcos epoch photometry", Monthly Notices of the Royal Astronomical Society, 331: 45, Bibcode:2002MNRAS.331...45K, arXiv:astro-ph/0112194 Freely accessible, doi:10.1046/j.1365-8711.2002.05150.x.
  12. ↑ Schröder, C.; Schmitt, J. H. M. M. (November 2007), "X-ray emission from A-type stars", Astronomy and Astrophysics, 475 (2): 677−684, Bibcode:2007A&A...475..677S, doi:10.1051/0004-6361:20077429.
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