Astronomy:HD 222093

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Short description: Double star system in the constellation Aquarius
HD 222093
Observation data
Equinox J2000.0]] (ICRS)
Constellation Aquarius
Right ascension  23h 37m 39.56021s[1]
Declination −13° 03′ 36.8732″[1]
Apparent magnitude (V) 5.68[2] + 9.6[3] or 11.19[4]
Characteristics
Evolutionary stage horizontal branch
Spectral type K0III[5]
U−B color index +0.81[2]
B−V color index +0.99[2]
Astrometry
Radial velocity (Rv)−12.56±0.15[1] km/s
Proper motion (μ) RA: +34.676[1] mas/yr
Dec.: +26.758[1] mas/yr
Parallax (π)11.1185 ± 0.1442[1] mas
Distance293 ± 4 ly
(90 ± 1 pc)
Details
Mass1.51[6] M
Radius10.00+0.47
−1.06
[1] R
Luminosity50.0±0.8[1] L
Surface gravity (log g)2.7[7] cgs
Temperature4,853+279
−110
[1] K
Metallicity [Fe/H]−0.25[7] dex
Rotational velocity (v sin i)0.0[7] km/s
Age3.17[6] Gyr
Other designations
BD−13°6439, HD 222093, HIP 116591, HR 8958, SAO 165804[8]
Database references
HD 222093
SIMBADdata
ADS 16878
SIMBADdata

HD 222093 is a double star in the equatorial constellation of Aquarius. It has an orange hue and is visible to the naked eye with an apparent visual magnitude of 5.68.[2] The system is located at a distance of approximately 293 light years from the Sun based on parallax, but is drifting closer with a radial velocity of −13 km/s.[1]

The primary component is an aging K-type giant star with a stellar classification of K0III,[5] which indicates it has exhausted the supply of hydrogen at its core then cooled and expanded. At present it has ten[1] times the Sun's radius. This is a red clump giant,[9] which indicates it is on the horizontal branch and is generating energy through helium fusion at its core. It is around three billion years old with 1.5 times the mass of the Sun.[6] The star is radiating fifty times the Sun's luminosity from its swollen photosphere at an effective temperature of 4,853 K.[1]

According to Eggleton and Tokovinin (2008), this is most likely a wide binary star system; the secondary companion is a magnitude 9.6 star at an angular separation of 33.1 from the primary.[3] However, the Washington Visual Double Star Catalog gives a magnitude of 11.19 with an angular separation of 30.2″.[4]

References

  1. 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 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 2.3 Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data. SIMBAD, Bibcode1986EgUBV........0M. 
  3. 3.0 3.1 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. 
  4. 4.0 4.1 Mason, B. D. et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal 122 (6): 3466, doi:10.1086/323920, Bibcode2001AJ....122.3466M, http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=B/wds, retrieved 2015-07-22. 
  5. 5.0 5.1 Houk, Nancy; Smith-Moore, M. (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, 4, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode1988mcts.book.....H. 
  6. 6.0 6.1 6.2 Luck, R. Earle (2015), "Abundances in the Local Region. I. G and K Giants", The Astronomical Journal 150 (3): 88, doi:10.1088/0004-6256/150/3/88, Bibcode2015AJ....150...88L. 
  7. 7.0 7.1 7.2 Massarotti, Alessandro et al. (January 2008), "Rotational and radial velocities for a sample of 761 HIPPARCOS giants and the role of binarity", The Astronomical Journal 135 (1): 209–231, doi:10.1088/0004-6256/135/1/209, Bibcode2008AJ....135..209M. 
  8. "HD 222093". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+222093. 
  9. Alves, David R. (August 2000), "K-Band Calibration of the Red Clump Luminosity", The Astrophysical Journal 539 (2): 732–741, doi:10.1086/309278, Bibcode2000ApJ...539..732A. 

External links