Upsilon Herculis

Upsilon Herculis (υ Her) is a solitary[10] star in the constellation Hercules. It is visible to the naked eye with an apparent visual magnitude of 4.74.[2] Based upon an annual parallax shift of 8.78 mas as seen from Earth, it is located around 371 light years from the Sun. At that distance, the visual magnitude is diminished by an extinction factor of 0.09 due to interstellar dust.[5]

Upsilon Herculis
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Hercules
Right ascension 16h 02m 47.89764s[1]
Declination +46° 02′ 12.1371″[1]
Apparent magnitude (V) 4.74[2]
Characteristics
Spectral type B9 III[3]
U−B color index −0.32[2]
B−V color index −0.11[2]
Astrometry
Radial velocity (Rv)+4.1±0.5[4] km/s
Proper motion (μ) RA: +55.42[1] mas/yr
Dec.: −61.29[1] mas/yr
Parallax (π)8.78 ± 0.18[1] mas
Distance371 ± 8 ly
(114 ± 2 pc)
Absolute magnitude (MV)0.32[5]
Details
Radius4.0[6] R☉
Luminosity173[7] L☉
Surface gravity (log g)3.80[8] cgs
Temperature10,152[7] K
Metallicity [Fe/H]−0.30[8] dex
Rotational velocity (v sin i)7.5[4] km/s
Age254[5] Myr
Other designations
υ Her, 6 Her, BD+46° 2142, HD 144206, HIP 78592, HR 5982, SAO 45865.[9]
Database references
SIMBADdata

At an estimated age of 254 million years,[5] this appears to be an evolved B-type giant star with a stellar classification of B9 III.[3] It is a mercury-manganese chemically peculiar star, indicating the spectrum shows abnormal abundances of these elements.[4] The star has about four times the radius of the Sun and it radiates 173[7] times the Sun's luminosity from its photosphere at an effective temperature of 10,152 K.[7]

References
  1. 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.
  2. Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data, SIMBAD, Bibcode:1986EgUBV........0M.
  3. Cowley, A.; et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal, 74: 375–406, Bibcode:1969AJ.....74..375C, doi:10.1086/110819
  4. Adelman, S. J.; et al. (February 2006), "Elemental abundance analyses with DAO spectrograms. XXIX. The mercury-manganese stars 53 Tau, β Tau, γ Crv, and υ Her", Astronomy and Astrophysics, 447 (2): 685–690, Bibcode:2006A&A...447..685A, doi:10.1051/0004-6361:20053581.
  5. Gontcharov, G. A. (November 2012), "Spatial distribution and kinematics of OB stars", Astronomy Letters, 38 (11): 694–706, arXiv:1606.09028, Bibcode:2012AstL...38..694G, doi:10.1134/S1063773712110035.
  6. Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics (3rd ed.), 367: 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451.
  7. McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–57, arXiv:1208.2037, Bibcode:2012MNRAS.427..343M, doi:10.1111/j.1365-2966.2012.21873.x.
  8. Smith, K. C.; Dworetsky, M. M. (July 1993), "Elemental Abundances in Normal Late B-Stars and Hgmn-Stars from Co-Added IUE Spectra - Part One - Iron Peak Elements", Astronomy and Astrophysics, 274 (2): 335, Bibcode:1993A&A...274..335S.
  9. "* ups Her -- Star". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-04-05.
  10. 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.
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