Astronomy:Mu2 Gruis

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Short description: Star in the constellation Grus


Mu2 Gruis
Observation data
Equinox J2000.0]] (ICRS)
Constellation Grus
Right ascension  22h 16m 26.54790s[1]
Declination −41° 37′ 37.8266″[1]
Apparent magnitude (V) 5.10[2]
Characteristics
Spectral type G8 III[3]
B−V color index +0.92[2]
Astrometry
Radial velocity (Rv)+12.50[4] km/s
Proper motion (μ) RA: −14.788[1] mas/yr
Dec.: −15.530[1] mas/yr
Parallax (π)13.1578 ± 0.1559[1] mas
Distance248 ± 3 ly
(76.0 ± 0.9 pc)
Absolute magnitude (MV)+0.56[5]
Details
Radius9.97+0.32
−0.20
[1] R
Luminosity56.37±0.78[1] L
Temperature5009+52
−79
[1] K
Other designations
μ2 Gru, CD−42° 15846, HD 211202, HIP 109973, HR 8488, SAO 231063[6]
Database references
SIMBADdata

Mu2 Gruis, Latinized from μ2 Gruis, is a yellow-hued star or star system in the southern constellation of Grus. It is a suspected astrometric binary, showing a variation in proper motion due to gravitational acceleration.[7] Mu2 Gruis is visible to the naked eye with an apparent visual magnitude of 5.10.[2] The distance to this system, as determined using an annual parallax shift of 13.2 mas as seen from the Earth,[1] is around 248 light years. It is drifting further away with a heliocentric radial velocity of +12.5 km/s.[4]

The primary component is an evolved giant star with a stellar classification of G8 III.[3] It is a periodic variable star, showing a change in brightness with an amplitude of 0.004 magnitude at the rate of 7.50983 times per day.[8] With the supply of hydrogen at its core exhausted, the star has cooled and expanded until now it has 10 times the radius of the Sun. It is radiating 56[1] times the luminosity of the Sun from its swollen photosphere at an effective temperature of 5,009 K.[1]

References

  1. 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 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 Johnson, H. L. et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory 4 (99): 99, Bibcode1966CoLPL...4...99J. 
  3. 3.0 3.1 Houk, N. (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, 2, Dept. of Astronomy, University of Michigan, Bibcode1978mcts.book.....H. 
  4. 4.0 4.1 Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system", Astronomy Letters 32 (11): 759–771, doi:10.1134/S1063773706110065, Bibcode2006AstL...32..759G. 
  5. Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  6. "mu.02 Gru -- Star", SIMBAD Astronomical Database (Centre de Données astronomiques de Strasbourg), http://simbad.u-strasbg.fr/simbad/sim-id?Ident=mu02+Gru, retrieved 2017-06-26. 
  7. Makarov, V. V.; Kaplan, G. H. (May 2005), "Statistical Constraints for Astrometric Binaries with Nonlinear Motion", The Astronomical Journal 129 (5): 2420–2427, doi:10.1086/429590, Bibcode2005AJ....129.2420M. 
  8. Koen, Chris; Eyer, Laurent (2002), "New periodic variables from the Hipparcos epoch photometry", Monthly Notices of the Royal Astronomical Society 331 (1): 45–59, doi:10.1046/j.1365-8711.2002.05150.x, Bibcode2002MNRAS.331...45K.