Rho Gruis

Rho Gruis
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Grus
Right ascension 22h 43m 29.97654s[1]
Declination −41° 24′ 51.6467″[1]
Apparent magnitude (V) 4.847[2]
Characteristics
Evolutionary stage horizontal branch[2]
Spectral type K0 III[3]
U−B color index +0.807[4]
B−V color index +1.026[4]
Astrometry
Radial velocity (Rv)30.89±0.15[5] km/s
Proper motion (μ) RA: +10.11[1] mas/yr
Dec.: −93.79[1] mas/yr
Parallax (π)14.16 ± 0.19 mas[1]
Distance230 ± 3 ly
(70.6 ± 0.9 pc)
Absolute magnitude (MV)0.685[2]
Details
Mass1.91[2] M☉
Radius12.15+0.19
−0.65[5] R☉
Luminosity66.9±1.3[5] L☉
Surface gravity (log g)2.62[2] cgs
Temperature4736.67+131.83
−36.67[5] K
Metallicity [Fe/H]−0.20[2] dex
Other designations
ρ Gru, CD−42° 16049, FK5 3818, HD 215104, HIP 112203, HR 8644, SAO 231265[6]
Database references
SIMBADdata

Rho Gruis, a Latinization of ρ Gruis, is a solitary[7] star in the southern constellation of Grus. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.85.[2] Based upon an annual parallax shift of 14.16 mas as seen from the Earth,[1] the system is located about 230 light years from the Sun. It is drifting further away with a radial velocity of 31 km/s.[5]

This object is an evolved K-type giant star with a stellar classification of K0 III.[3] It has exhausted the supply of hydrogen at its core, causing it to cool and expand. At present it has 12[5] times the radius of the Sun. With 1.9 times the mass of the Sun[2] it is a red clump star,[2] which indicates it is on the horizontal branch generating energy through helium fusion at its core. It is radiating 67[5] times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,737 K.[5]

Rho Gruis has two visual companions: a magnitude 14.0 star at an angular separation of 19.3″ along a position angle (PA) of 302°, as of 2011, and a magnitude 10.28 star with a separation of 114.20″ and a PA of 336°, as of 1999.[8]

References

  1. ^ a b c d e f van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
  2. ^ a b c d e f g h i Liu, Y. J.; et al. (2007), "The abundances of nearby red clump giants", Monthly Notices of the Royal Astronomical Society, 382 (2): 553–66, Bibcode:2007MNRAS.382..553L, doi:10.1111/j.1365-2966.2007.11852.x.
  3. ^ a b Houk, N. (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 2, Dept. of Astronomy, University of Michigan, Bibcode:1978mcts.book.....H.
  4. ^ a b Cousins, A. W. J. (1983), "UBV photometry of E region standard stars of intermediate brightness", South African Astronomical Observatory Circular, 7 (7): 36–46, Bibcode:1983SAAOC...7...36C.
  5. ^ a b c d e f g h Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  6. ^ "* rho Gru". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-06-24.{{cite web}}: CS1 maint: postscript (link)
  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, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
  8. ^ Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122 (6): 3466, Bibcode:2001AJ....122.3466M, doi:10.1086/323920