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H Scorpii

H Scorpii and the dark clouds Barnard 231
Credit: DECaPS DR2
Observation data
Epoch J2000.0       Equinox J2000.0 ( ICRS)
Constellation Scorpius
Right ascension 16h 36m 22.47192s [1]
Declination −35° 15′ 19.1803″ [1]
Apparent magnitude (V) 4.18 [2]
Characteristics
Evolutionary stage giant [3]
Spectral type K6III [4]
B−V color index 1.535±0.069 [2]
Astrometry
Radial velocity (Rv)−2.10±0.7 [5] km/s
Proper motion (μ) RA: 15.61±0.17  mas/ yr [1]
Dec.: 11.33±0.14  mas/ yr [1]
Parallax (π)9.52 ± 0.16  mas [1]
Distance343 ± 6  ly
(105 ± 2  pc)
Absolute magnitude (MV)−0.84±0.037 [6]
Details
Mass1.06+0.74
−0.28
  M
[7]
1.81 [8]  M
Radius52.79±5.47 [3]  R
Luminosity389 L [7]
562 L [8]
582±147 [3]  L
Surface gravity (log g)1.30±0.15 [3]  cgs
Temperature3,875±21 [8]  K
Metallicity [Fe/H]0.00±0.20 dex [3]
−0.30 [7]  dex
Rotational velocity (v sin i)3.1 [9] km/s
Age2.18 [8]  Gyr
Other designations
H Sco, NSV 7844, CD−34° 11112, GC 22311, HD 149447, HIP 81304, HR 6166, SAO 207814, PPM 295235 [10]
Database references
SIMBAD data

H Scorpii (H Sco) is a single [11] star in the southern constellation Scorpius. It is faintly visible to the naked eye with an apparent visual magnitude of 4.18. [2] The star is located at a distance of approximately 343  light-years from the Sun based on parallax measurements, but is drifting closer with a radial velocity of −2 km/s. [5] This star was initially given the Bayer designation Beta Normae by Lacaille but it was later reassigned from Norma to Scorpius. [12]

This is an aging giant star with a stellar classification of K6III. [4] After exhausting the supply of hydrogen at its core, this star cooled and expanded off the main sequence. It now has around 53 times the radius of the Sun. [3] The star is about 2.2 [8] billion years old with only a mild level of magnetic activity, and is spinning with a projected rotational velocity of 3.1 km/s. [9] It is radiating 4–600 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 3,875 K. [8]

References

  1. ^ a b c d van Leeuwen, F. (2007). "Validation of the New Hipparcos Reduction". Astronomy and Astrophysics. 474 (2): 653–64. arXiv: 0708.1752. Bibcode: 2007A&A...474..653V. doi: 10.1051/0004-6361:20078357. S2CID  18759600.
  2. ^ a b c Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv: 1108.4971. Bibcode: 2012AstL...38..331A. doi: 10.1134/S1063773712050015. S2CID  119257644.
  3. ^ a b c d e f Decin, L.; et al. (March 2003). "ISO-SWS calibration and the accurate modelling of cool-star atmospheres. IV. G9 to M2 stars". Astronomy and Astrophysics. 400 (2): 709–727. arXiv: astro-ph/0207653. Bibcode: 2003A&A...400..709D. doi: 10.1051/0004-6361:20021786. S2CID  55244849.
  4. ^ a b Houk, Nancy (1979). Michigan catalogue of two-dimensional spectral types for the HD stars. Vol. 3. Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan. Bibcode: 1982mcts.book.....H.
  5. ^ a b Gontcharov, G. A. (November 2006). "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv: 1606.08053. Bibcode: 2006AstL...32..759G. doi: 10.1134/S1063773706110065. S2CID  119231169.
  6. ^ Park, Sunkyung; et al. (2013). "Wilson-Bappu Effect: Extended to Surface Gravity". The Astronomical Journal. 146 (4): 73. arXiv: 1307.0592. Bibcode: 2013AJ....146...73P. doi: 10.1088/0004-6256/146/4/73. S2CID  119187733.
  7. ^ a b c Charbonnel, C.; et al. (2020-01-01). "Lithium in red giant stars: Constraining non-standard mixing with large surveys in the Gaia era". Astronomy and Astrophysics. 633: A34. arXiv: 1910.12732. Bibcode: 2020A&A...633A..34C. doi: 10.1051/0004-6361/201936360. ISSN  0004-6361. S2CID  204907220.
  8. ^ a b c d e f Luck, R. Earle (2015). "Abundances in the Local Region. I. G and K Giants". Astronomical Journal. 150 (3). 88. arXiv: 1507.01466. Bibcode: 2015AJ....150...88L. doi: 10.1088/0004-6256/150/3/88. S2CID  118505114.
  9. ^ a b Pérez Martínez, M. I.; et al. (November 2014). "The non-active stellar chromosphere: Ca II basal flux". Monthly Notices of the Royal Astronomical Society. 445 (1): 270–279. Bibcode: 2014MNRAS.445..270P. doi: 10.1093/mnras/stu1706.
  10. ^ "H Sco". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-11-12.
  11. ^ 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. S2CID  14878976.
  12. ^ Ridpath, Ian (June 28, 2018). "Norma, the Set Square". Ian Ridpath's Star Tales. Retrieved 2021-11-13.