Astronomy:50 Aquarii

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Short description: Star in the constellation Aquarius
50 Aquarii
Observation data
Equinox J2000.0]] (ICRS)
Constellation Aquarius
Right ascension  22h 24m 27.06016s[1]
Declination −13° 31′ 45.7290″[1]
Apparent magnitude (V) 5.76[2]
Characteristics
Spectral type G7.5 III[3]
B−V color index 0.970±0.004[2]
Astrometry
Radial velocity (Rv)−21.1±2.9[2] km/s
Proper motion (μ) RA: +98.380[1] mas/yr
Dec.: −2.909[1] mas/yr
Parallax (π)12.2800 ± 0.0965[1] mas
Distance266 ± 2 ly
(81.4 ± 0.6 pc)
Absolute magnitude (MV)+0.03[2]
Details[4]
Mass2.49±0.25 M
Radius14.17±0.81 R
Luminosity103.7±11.5 L
Surface gravity (log g)2.55±0.07 cgs
Temperature4,897±34 K
Metallicity [Fe/H]−0.21±0.10 dex
Rotational velocity (v sin i)4.07[5] km/s
Age620±170 Myr
Other designations
CD−14° 6276, HD 212430, HIP 110602, HR 8534, SAO 165044[6]
Database references
SIMBADdata

50 Aquarii, abbreviated 50 Aqr, is a single[7] star in the zodiac constellation of Aquarius. 50 Aquarii is its Flamsteed designation. It is a faint star with an apparent visual magnitude of 5.76[2] that is barely visible to the naked eye under good seeing conditions. The star is located near the ecliptic and thus is subject to lunar occultations.[8] Based upon an annual parallax shift of 12.2 mas[1] as seen from Earth orbit, it is located 266 light years away. It is moving closer to the Earth with a heliocentric radial velocity of −21 km/s.[2]

This is an evolved giant star with a stellar classification of G7.5 III[3] that is most likely (87% chance) on the red giant branch.[4] As such, it is estimated to be 620 million years old with 2.5 times the mass of the Sun and has expanded to 14 times the Sun's radius. The star is radiating 104 times the Sun's luminosity from its expanded photosphere at an effective temperature of 4,897 K.[4]

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. 
  2. 2.0 2.1 2.2 2.3 2.4 2.5 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 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. 
  4. 4.0 4.1 4.2 Reffert, Sabine et al. (2015), "Precise radial velocities of giant stars. VII. Occurrence rate of giant extrasolar planets as a function of mass and metallicity", Astronomy & Astrophysics 574: A116, doi:10.1051/0004-6361/201322360, Bibcode2015A&A...574A.116R.  Note: the infobox values are based on the RGB model.
  5. Hekker, S.; Meléndez, J. (2007), "Precise radial velocities of giant stars. III. Spectroscopic stellar parameters", Astronomy and Astrophysics 475 (3): 1003, doi:10.1051/0004-6361:20078233, Bibcode2007A&A...475.1003H. 
  6. "50 Aqr". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=50+Aqr. 
  7. 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. 
  8. Blow, G. L. et al. (November 1982), "Photoelectric observations of lunar occultations. XIII", Astronomical Journal 87: 1571–1584, doi:10.1086/113247, Bibcode1982AJ.....87.1571B.  See p. 1578, SAO 165044.