Astronomy:Omicron Boötis

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Short description: Star in the constellation Boötes
Omicron Boötes
Observation data
Equinox J2000.0]] (ICRS)
Constellation Boötes
Right ascension  14h 45m 14.46026s[1]
Declination +16° 57′ 51.4078″[1]
Apparent magnitude (V) +4.60[2]
Characteristics
Spectral type G8.5 III[3]
U−B color index +0.75[2]
B−V color index +0.98[2]
Astrometry
Radial velocity (Rv)−9.18[4] km/s
Proper motion (μ) RA: −60.69[1] mas/yr
Dec.: −50.56[1] mas/yr
Parallax (π)13.42 ± 0.24[1] mas
Distance243 ± 4 ly
(75 ± 1 pc)
Absolute magnitude (MV)0.70[5]
Details
Mass2.05[4] M
Radius11[6] R
Luminosity85[4] L
Surface gravity (log g)2.7[6] cgs
Temperature4,864±25[4] K
Metallicity [Fe/H]−0.10[6] dex
Rotational velocity (v sin i)3.6[6] km/s
Age2.72[4] Gyr
Other designations
ο Boo, 35 Boötis, BD+17° 2780, GC 19858, GJ 9493, HD 129972, HIP 72125, HR 5502, SAO 101184[7]
Database references
SIMBADdata

Omicron Boötis (ο Boötis) is a yellow-hued star in the northern constellation of Boötes. With an apparent visual magnitude of +4.60,[2] it is a fifth magnitude star that is visible to the naked eye. Based upon an annual parallax shift of 13.42 mas as seen from the Earth,[1] it is located about 243 light years from the Sun. The star is moving closer to the Sun with a radial velocity of −9 km/s.[6]

At the age of 2.72 billion years,[4] this is an evolved G-type giant star with a stellar classification of G8.5 III.[3] It belongs to the so-called "red clump", which indicates it is generating energy through helium fusion at its core.[8] Although it displays a higher abundance of barium than is normal for a star of its type, Williams (1975) considers its status as a Barium star to be "very doubtful".[9] The star has double[4] the mass of the Sun and has expanded to 11[6] times the Sun's radius. It is radiating 85 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,864 K.[4]

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 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 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 4.3 4.4 4.5 4.6 4.7 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. 
  5. McWilliam, Andrew (December 1990), "High-resolution spectroscopic survey of 671 GK giants. I - Stellar atmosphere parameters and abundances", Astrophysical Journal Supplement Series 74: 1075–1128, doi:10.1086/191527, Bibcode1990ApJS...74.1075M. 
  6. 6.0 6.1 6.2 6.3 6.4 6.5 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. 
  7. "omi Boo". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=omi+Boo. 
  8. 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. 
  9. Williams, P. M. (February 1975), "Stellar compositions from narrow-band photometry - V. Barium abundances for 200 evolved stars", Monthly Notices of the Royal Astronomical Society 170 (2): 343–362, doi:10.1093/mnras/170.2.343, Bibcode1975MNRAS.170..343W. 

External links