Astronomy:HR 6594

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Short description: Binary star system in the constellation of Hercules
HR 6594
Observation data
Equinox J2000.0]] (ICRS)
Constellation Hercules[1]
Right ascension  17h 41m 58.632s[2]
Declination +15° 57′ 08.76″[2]
Apparent magnitude (V) 5.54[1]
Characteristics
Evolutionary stage Main sequence[3]
Spectral type F4 Vw[4]
U−B color index −0.05[5]
B−V color index +0.387±0.012[1]
Astrometry
Radial velocity (Rv)−43.7[6] km/s
Proper motion (μ) RA: −1.868[2] mas/yr
Dec.: +101.120[2] mas/yr
Parallax (π)28.5131 ± 0.0532[2] mas
Distance114.4 ± 0.2 ly
(35.07 ± 0.07 pc)
Absolute magnitude (MV)+2.74[7]
Details
HR 6594 A
Mass1.33[8] M☉
Radius1.91[8] R☉
Luminosity5.8[8] L☉
Surface gravity (log g)4.00[8] cgs
Temperature6,488[8] K
Metallicity [Fe/H]−0.04[9] dex
Rotational velocity (v sin i)31.7[3] km/s
Age1.2[10] Gyr
Other designations
BD−16°3256, HD 160910, HIP 86623, HR 6594, SAO 103033[11]
Database references
SIMBADdata

HR 6594 is the Bright Star Catalogue designation for a binary star[12] system in the northern constellation of Hercules. It is faintly visible to the naked eye with an apparent visual magnitude of 5.54;[1] according to the Bortle scale, it is sufficiently bright to be visible from dark suburban skies. The distance to this system, as determined using parallax measurements,[2] is about 114 light years. It is drifting closer with a heliocentric radial velocity of −43.7 km/s,[6] and is predicted to come as near as 47 light-years in 686,000 years.[1] On the celestial sphere it is located near the star Alpha Ophiuchi; their projected separation is just 3 light years, although their actual separation is much greater.[13]

The primary is an F-type main sequence star with a stellar classification of F4 Vw, where the w indicates relatively weak metallic features in the ultraviolet spectrum.[4] This star has 133% of the Sun's mass 191% of the solar radius.[8] It is spinning with a projected rotational velocity of 31.7 km/s,[3] and is around 1.2 billion years old.[10] The effective temperature of the outer atmosphere is 6,488 K.[8] giving it the yellow-white hue of an F-type star.[14] The abundance of elements other than hydrogen or helium, what astronomers term the metallicity, is similar to that in the Sun.[9]

It has a magnitude 9.38 companion star orbiting with a 144-year period, a semimajor axis spanning 1.04 arcseconds, and an eccentricity of 0.42.[12] There is a third, visual companion of magnitude 14.46 at an angular separation of 154.70 arcseconds along a position angle of 271°, as of 2001.[15]

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A  XHIP record for this object at VizieR.
  2. ↑ 2.0 2.1 2.2 2.3 2.4 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.
  3. ↑ 3.0 3.1 3.2 Schröder, C. et al. (January 2009), "Ca II HK emission in rapidly rotating stars. Evidence for an onset of the solar-type dynamo", Astronomy and Astrophysics 493 (3): 1099–1107, doi:10.1051/0004-6361:200810377, Bibcode: 2009A&A...493.1099S. 
  4. ↑ 4.0 4.1 Barry, Don C. (1970), "Spectral Classification of A and F Stars", Astrophysical Journal Supplement 19: 281, doi:10.1086/190209, Bibcode: 1970ApJS...19..281B. 
  5. ↑ Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data (SIMBAD), Bibcode: 1986EgUBV........0M. 
  6. ↑ 6.0 6.1 Wilson, R. E. (1953), "General Catalogue of Stellar Radial Velocities", Carnegie Institute Washington D.C. Publication (Carnegie Institute of Washington D.C.), Bibcode: 1953GCRV..C......0W. 
  7. ↑ Boesgaard, A. M.; Tripicco, M. J. (April 15, 1986), "Lithium in early F dwarfs", Astrophysical Journal, Part 1 303: 724–739, doi:10.1086/164120, Bibcode: 1986ApJ...303..724B. 
  8. ↑ 8.0 8.1 8.2 8.3 8.4 8.5 8.6 Stassun, Keivan G. et al. (2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal 158 (4): 138. doi:10.3847/1538-3881/ab3467. Bibcode: 2019AJ....158..138S. 
  9. ↑ 9.0 9.1 Casagrande, L. et al. (2011), "New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey", Astronomy & Astrophysics 530 (A138): 21, doi:10.1051/0004-6361/201016276, Bibcode: 2011A&A...530A.138C. 
  10. ↑ 10.0 10.1 David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal 804 (2): 146, doi:10.1088/0004-637X/804/2/146, Bibcode: 2015ApJ...804..146D. 
  11. ↑ "HR 6594". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HR+6594. 
  12. ↑ 12.0 12.1 Malkov, O. Yu. et al. (October 2012), "Dynamical masses of a selected sample of orbital binaries", Astronomy & Astrophysics 546: 5, doi:10.1051/0004-6361/201219774, A69, Bibcode: 2012A&A...546A..69M. 
  13. ↑ Redfield, Seth et al. (June 2007), "Spitzer Limits on Dust Emission and Optical Gas Absorption Variability around Nearby Stars with Edge-on Circumstellar Disk Signatures", The Astrophysical Journal 661 (2): 944–971, doi:10.1086/517516, Bibcode: 2007ApJ...661..944R. 
  14. ↑ "The Colour of Stars", Australia Telescope, Outreach and Education (Commonwealth Scientific and Industrial Research Organisation), December 21, 2004, http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html, retrieved 2012-01-16. 
  15. ↑ Mason, B. D. et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal 122 (6): 3466–3471, doi:10.1086/323920, Bibcode: 2001AJ....122.3466M, http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=B/wds, retrieved 2015-07-22.