Astronomy:Omicron Boötis

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Short description: Star in the constellation Boötes
ο Boötis
Location of ο Boötis (circled in red)
Observation data
Equinox J2000.0]] (ICRS)
Constellation Boötes
Right ascension  14h 45m 14.461s[1]
Declination +16° 57′ 51.40″[1]
Apparent magnitude (V) +4.60[2]
Characteristics
Evolutionary stage red clump[3]
Spectral type G8.5 III[4]
U−B color index +0.75[2]
B−V color index +0.98[2]
Astrometry
Radial velocity (Rv)−9.18[5] km/s
Proper motion (μ) RA: −59.581[1] mas/yr
Dec.: −52.524[1] mas/yr
Parallax (π)12.6814 ± 0.1385[1] mas
Distance257 ± 3 ly
(78.9 ± 0.9 pc)
Absolute magnitude (MV)0.70[6]
Details
Mass2.05[5] M
Radius11[7] R
Luminosity85[5] L
Surface gravity (log g)2.7[7] cgs
Temperature4,864±25[5] K
Metallicity [Fe/H]−0.10[7] dex
Rotational velocity (v sin i)3.6[7] km/s
Age2.72[5] Gyr
Other designations
ο Boo, 35 Boötis, BD+17°2780, GC 19858, GJ 9493, HD 129972, HIP 72125, HR 5502, SAO 101184[8]
Database references
SIMBADdata

Omicron Boötis is a yellow-hued star in the northern constellation of Boötes. Its name is a Bayer designation that is Latinized from ο Boötis, and abbreviated Omicron Boo or ο Boo. With an apparent visual magnitude of +4.60,[2] it is a fifth magnitude star that is faintly visible to the naked eye. Based upon an annual parallax shift of 12.68 mas as seen from the Earth,[1] it is located at a distance of approximately 257 light-years (78.9 pc). The star is moving closer to the Sun with a radial velocity of −9 km/s.[7]

At the age of 2.72 billion years,[5] this is an evolved G-type giant star with a stellar classification of G8.5 III.[4] It belongs to the so-called red clump, which indicates it is generating energy through helium fusion at its core.[3] 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[5] the mass of the Sun and has expanded to 11[7] 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.[5]

References

  1. 1.0 1.1 1.2 1.3 1.4 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940.  Gaia DR3 record for this source at VizieR.
  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 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. 
  4. 4.0 4.1 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. 
  5. 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 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. 
  6. 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. 
  7. 7.0 7.1 7.2 7.3 7.4 7.5 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. 
  8. "omi Boo". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=omi+Boo. 
  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.