Astronomy:HD 211073

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Short description: Triple star system in the constellation Lacerta
HD 211073
Observation data
Equinox J2000.0]] (ICRS)
Constellation Lacerta
Right ascension  22h 13m 52.72731s[1]
Declination +39° 42′ 53.7442″[1]
Apparent magnitude (V) 4.50[2] (4.49–4.55)[3]
Characteristics
Spectral type K2.5 III[4]
B−V color index 1.39[5]
Astrometry
Radial velocity (Rv)−11.69±0.13[5] km/s
Proper motion (μ) RA: +39.155[1] mas/yr
Dec.: +18.441[1] mas/yr
Parallax (π)5.5806 ± 0.2705[1] mas
Distance580 ± 30 ly
(179 ± 9 pc)
Absolute magnitude (MV)−1.34[2]
Details[6]
HD 211073 Aa
Mass2.23+0.22
−0.26
 M
Radius45.69+2.17
−2.39
 R
Luminosity573.50+51.88
−61.58
 L
Surface gravity (log g)1.46+0.05
−0.04
 cgs
Temperature4,180+12
−14
 K
Rotational velocity (v sin i)2.9±1.0[5] km/s
Age1.00+0.38
−0.19
 Myr
Other designations
NSV 14076, BD+38° 4711, FK5 1583, HD 211073, HIP 109754, HR 8485, SAO 72155, WDS J22139+3943[7]
Database references
SIMBADdata

HD 211073 is a triple star[8] system in the northern constellation Lacerta, located around 580[1] light years from the Sun. It is visible to the naked eye as a faint orange-hued star with a baseline apparent visual magnitude of 4.50.[2] The system is moving closer to the Earth with a heliocentric radial velocity of −11.7 km/s.[5]

The primary member, designated component Aa, is an evolved giant star with a stellar classification of K2.5 III[4] that is most likely (98% chance) on the horizontal branch.[6] It is a suspected variable star that ranges in magnitude from 4.49 down to 4.55.[3] This star is around a billion years old with 2.2 times the mass of the Sun and has expanded to 46 times the Sun's radius. It is radiating about 574 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,180 K.[6]

As of 2005, the inner pair of stars (Aa + Ab) in this system had an angular separation of 0.20 along a position angle (PA) of 170°. The magnitude 8.15 component Ac was separated from Aa by 0.30″ with a PA of 27°, as of 2010. As of 2015, the magnitude 10.60 visual companion, designated component B, was separated from the primary by 30.50″ along a PA of 190°.[9]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  2. 2.0 2.1 2.2 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  3. 3.0 3.1 Samus, N. N. et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1 61 (1): 80–88, doi:10.1134/S1063772917010085, Bibcode2017ARep...61...80S. 
  4. 4.0 4.1 Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series 71: 245, doi:10.1086/191373, Bibcode1989ApJS...71..245K. 
  5. 5.0 5.1 5.2 5.3 De Medeiros, J. R.; Mayor, M. (1999), "A catalog of rotational and radial velocities for evolved stars", Astronomy and Astrophysics Supplement Series 139 (3): 433, doi:10.1051/aas:1999401, Bibcode1999A&AS..139..433D. 
  6. 6.0 6.1 6.2 Stock, Stephan et al. (August 2018), "Precise radial velocities of giant stars. X. Bayesian stellar parameters and evolutionary stages for 372 giant stars from the Lick planet search", Astronomy & Astrophysics 616: 15, doi:10.1051/0004-6361/201833111, A33, Bibcode2018A&A...616A..33S. 
  7. "HD 211073". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+211073. 
  8. Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society 389 (2): 869–879, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode2008MNRAS.389..869E. 
  9. Mason, Brian D. et al. (December 2001), "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog", The Astronomical Journal 122 (6): 3466–3471, doi:10.1086/323920, Bibcode2001AJ....122.3466M.