Astronomy:Upsilon Geminorum

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Short description: Evolved red giant star in the constellation Gemini
υ Geminorum
Observation data
Equinox J2000.0]] (ICRS)
Constellation Gemini
Right ascension  07h 35m 55.34970s[1]
Declination +26° 53′ 44.6751″[1]
Apparent magnitude (V) 4.04[2] (4.04 - 4.08[3])
Characteristics
Spectral type M0 III[4]
U−B color index +1.96[2]
B−V color index +1.54[2]
Variable type suspected[3]
Astrometry
Radial velocity (Rv)−21.61±0.19[5] km/s
Proper motion (μ) RA: −34.12[1] mas/yr
Dec.: -106.96[1] mas/yr
Parallax (π)12.04 ± 0.68[1] mas
Distance270 ± 20 ly
(83 ± 5 pc)
Absolute magnitude (MV)−0.53[6]
Details
Mass1.52[7] M
Radius44[5] R
Luminosity417[5] L
Surface gravity (log g)1.0[5] cgs
Temperature3,926±16[5] K
Metallicity [Fe/H]0.17[7] dex
Rotational velocity (v sin i)5.9[5] km/s
Age3.53[7] Gyr
Other designations
υ Gem, 69 Geminorum, BD+27° 1424, FK5 1196, HD 60522, HIP 36962, HR 2905, SAO 79533.[8]
Database references
SIMBADdata

Upsilon Geminorum, Latinized from υ Geminorum, is a star in the constellation Gemini. It has an apparent visual magnitude of 4.04,[2] which is bright enough to be seen with the naked eye. Based upon an annual parallax shift of 12.04 mas,[1] it is around 270 light years from the Sun. There is a visual companion: a magnitude 13.20 star located at an angular separation of 55.20 along a position angle of 40°, as of 2008.[9]

This is an evolved red giant star with a stellar classification of M0 III.[4] It is estimated to have 1.52[7] times the mass of the Sun, but has expanded to 44[5] times the Sun's radius. The star is spinning with a projected rotational velocity of 5.9 km/s[5] and is about 3.53[7] billion years old. Upsilon Geminorum is radiating 417 times the solar luminosity from its outer atmosphere at an effective temperature of 3926 K.[5]

Based upon the motion of this star through space, Upsilon Geminorum is a member of the Wolf 630 moving group. This is a set of stars centered on Wolf 630 that are moving nearly in parallel and have an age of around 2.7±0.5 billion years. They may be former members of a dissolved open cluster.[10]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode2007A&A...474..653V. 
  2. 2.0 2.1 2.2 2.3 Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data (SIMBAD), Bibcode1986EgUBV........0M. 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 Samus, N. N. et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S 1. Bibcode2009yCat....102025S. 
  4. 4.0 4.1 Morgan, W. W.; Keenan, P. C. (1973), "Spectral Classification", Annual Review of Astronomy and Astrophysics 11: 29, doi:10.1146/annurev.aa.11.090173.000333, Bibcode1973ARA&A..11...29M. 
  5. 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 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. 
  6. Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  7. 7.0 7.1 7.2 7.3 7.4 Luck, R. Earle (September 2015), "Abundances in the Local Region. I. G and K Giants", The Astronomical Journal 150 (3): 23, doi:10.1088/0004-6256/150/3/88, 88, Bibcode2015AJ....150...88L. 
  8. "ups Gem". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=ups+Gem. 
  9. Mason, B. D. et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal 122 (6): 3466–3471, doi:10.1086/323920, Bibcode2001AJ....122.3466M. 
  10. Bubar, Eric J.; King, Jeremy R. (August 2010), "Spectroscopic Abundances and Membership in the Wolf 630 Moving Group", The Astronomical Journal 140 (2): 293–318, doi:10.1088/0004-6256/140/2/293, Bibcode2010AJ....140..293B. 

External links