astro.wikisort.org - Star

Search / Calendar

Zeta2 Lyrae is a single,[10] white-hued star in the northern constellation of Lyra. It is a dim star that is just visible to the naked eye with an apparent visual magnitude of 5.74[2] An annual parallax shift of 20.6 mas as seen from Earth provides a distance estimate of about 158 light years from the Sun. It is moving closer to the Sun with a radial velocity of −25 km/s.[5]

For other stars with this Bayer designation, see ζ Lyrae.
Zeta2 Lyrae
Observation data
Epoch J2000      Equinox J2000
Constellation Lyra
Right ascension 18h 44m 48.19919s[1]
Declination +37° 35′ 40.5585″[1]
Apparent magnitude (V) 5.74[2]
Characteristics
Spectral type F0 IVn[3] or F1Vnn[4]
U−B color index +0.06[2]
B−V color index +0.29[2]
Astrometry
Radial velocity (Rv)−25.0±3.7[5] km/s
Proper motion (μ) RA: +23.969[1] mas/yr
Dec.: +23.461[1] mas/yr
Parallax (π)20.6386 ± 0.0443 mas[1]
Distance158.0 ± 0.3 ly
(48.5 ± 0.1 pc)
Absolute magnitude (MV)+2.34[6]
Details
Mass1.74[7] M☉
Radius2.03±0.02[1] R☉
Luminosity9.5±0.1[1] L☉
Surface gravity (log g)3.94[7] cgs
Temperature7,257+37
−3[1] K
Metallicity [Fe/H]−0.36[1] dex
Rotational velocity (v sin i)212[8] km/s
Age1.223[7] Gyr
Other designations
ζ2 Lyr, 7 Lyr, BD+37°3223, GC 25678, HD 173649, HIP 91973, HR 7057, SAO 67324, WDS J18448+3736D[9]
Database references
SIMBADdata
ζ1 and ζ2 Lyrae photographed by amateur astronomer David Chifiriuc in 2020. The separation between the two stars is 43.7″.
ζ1 and ζ2 Lyrae photographed by amateur astronomer David Chifiriuc in 2020. The separation between the two stars is 43.7″.

This star has a stellar classification of F0 IVn,[3] suggesting it is an F-type subgiant star that is evolving away from the main sequence as its supply of hydrogen at the core has been consumed. The n suffix indicates "nebulous" lines caused by its rotation. It is spinning rapidly with a projected rotational velocity of 212 km/s.[8] This is giving the star an oblate shape with an equatorial bulge that is an estimated 29% larger than the polar radius.[11] The star is radiating approximately 9.6 times the Sun's luminosity from the photosphere at an effective temperature of about 7,000 K.[1] It has 1.7[7] times the mass of the Sun, twice the Sun's radius,[1] and is about 1.2[7] billion years old.

It is a suspected variable.[9]


References


  1. Vallenari, A.; et al. (Gaia Collaboration) (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. arXiv:2208.00211. doi:10.1051/0004-6361/202243940. Gaia DR3 record for this source at VizieR.
  2. Deutschman, W. A.; et al. (February 1976), "The galactic distribution of interstellar absorption as determined from the Celescope catalog of ultraviolet stellar observations and a new catalogue of UBV, Hbeta photoelectric observations", Astrophysical Journal Supplement Series, 30: 97–225, Bibcode:1976ApJS...30...97D, doi:10.1086/190359.
  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. Gray, R. O.; Napier, M. G.; Winkler, L. I. (2001), "The Physical Basis of Luminosity Classification in the Late A-, F-, and Early G-Type Stars. I. Precise Spectral Types for 372 Stars", The Astronomical Journal, 121 (4): 2148, Bibcode:2001AJ....121.2148G, doi:10.1086/319956.
  5. Kharchenko, N. V.; et al. (2007), "Astrophysical supplements to the ASCC-2.5: Ia. Radial velocities of ˜55000 stars and mean radial velocities of 516 Galactic open clusters and associations", Astronomische Nachrichten, 328 (9): 889–896, arXiv:0705.0878, Bibcode:2007AN....328..889K, doi:10.1002/asna.200710776, S2CID 119323941.
  6. Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
  7. David, Trevor J.; Hillenbrand, Lynne A. (2015). "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets". The Astrophysical Journal. 804 (2): 146. arXiv:1501.03154. Bibcode:2015ApJ...804..146D. doi:10.1088/0004-637X/804/2/146. S2CID 33401607. Vizier catalog entry
  8. Royer, F.; Zorec, J.; Gómez, A. E. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics, 463 (2): 671–682, arXiv:astro-ph/0610785, Bibcode:2007A&A...463..671R, doi:10.1051/0004-6361:20065224, S2CID 18475298.
  9. "zet02 Lyr". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 25 July 2015.
  10. De Rosa, R. J.; et al. (2014). "The VAST Survey - III. The multiplicity of A-type stars within 75 pc". Monthly Notices of the Royal Astronomical Society. 437 (2): 1216. arXiv:1311.7141. Bibcode:2014MNRAS.437.1216D. doi:10.1093/mnras/stt1932.
  11. Belle, G. T. (2012). "Interferometric observations of rapidly rotating stars". The Astronomy and Astrophysics Review. 20 (1): 51. arXiv:1204.2572. Bibcode:2012A&ARv..20...51V. doi:10.1007/s00159-012-0051-2. S2CID 119273474.


Текст в блоке "Читать" взят с сайта "Википедия" и доступен по лицензии Creative Commons Attribution-ShareAlike; в отдельных случаях могут действовать дополнительные условия.

Другой контент может иметь иную лицензию. Перед использованием материалов сайта WikiSort.org внимательно изучите правила лицензирования конкретных элементов наполнения сайта.

2019-2025
WikiSort.org - проект по пересортировке и дополнению контента Википедии