HD 119921

Last updated
HD 119921
Observation data
Epoch J2000       Equinox J2000
Constellation Centaurus [1]
Right ascension 13h 46m 56.35149s [2]
Declination −36° 15′ 06.9563″ [2]
Apparent magnitude  (V)5.15 [1]
Characteristics
Spectral type A0 V [3] [4] or B9.5 III-n [5]
Astrometry
Radial velocity (Rv)−9.8±2.8 [6] km/s
Proper motion (μ)RA: −13.293 [2] mas/yr
Dec.: −11.115 [2] mas/yr
Parallax (π)7.7881±0.2382  mas [2]
Distance 420 ± 10  ly
(128 ± 4  pc)
Absolute magnitude  (MV)−0.48 [1]
Details
Mass 2.6 [7]   M☉
Radius 4.1 [7]   R☉
Luminosity 160 [7]   L☉
Surface gravity (log g)3.62 [7]   cgs
Temperature 10,102 [7]   K
Rotational velocity (v sin i)220 [8]  km/s
Age 337 [9]   Myr
Other designations
z Cen, CD−35°8995, FK5 3091, HD 119921, HIP 67244, HR 5174, SAO 204835, WDS J13469-3615A [10]
Database references
SIMBAD data

HD 119921 is a single, [4] white-hued star in the southern constellation of Centaurus. it has the Bayer designation z Centauri. This is faintly visible to the naked eye, having an apparent visual magnitude of 5.15. [1] It forms a wide double star with a faint, magnitude 12.50 visual companion, which is located at an angular separation of 27.20″ as of 2010. [11] HD 119921 is moving closer to us with a heliocentric radial velocity of around −10 km/s, [6] and is currently located some 420±10  light year from the Sun. At that distance, the visual magnitude of this star is diminished by 0.15 from extinction due to interstellar dust. [9]

This is an A-type main-sequence star with a stellar classification of A0 V, per Houk (1979). [3] However, Gray & Garrison (1987) have it classed as B9.5 III-n, suggesting it is a more evolved giant star. [5] HD 119921 is spinning rapidly with a projected rotational velocity of 220 km/s. [8] The star is radiating around 160 times the Sun's luminosity from its photosphere at an effective temperature of 10,102  K . [7]

In 1983, Molaro et al. reported the presence of super-ionized elements (triple-ionized carbon and silicon) in the far ultraviolet spectrum of HD 119921. These anomalous features are not normally detected from a star in this temperature range. [12] Instead, these blue-shifted absorption features may originate in the local interstellar medium. [8]

References

  1. 1 2 3 4 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. XHIP record for this object at VizieR.
  2. 1 2 3 4 5 Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics . 616. A1. arXiv: 1804.09365 . Bibcode: 2018A&A...616A...1G . doi: 10.1051/0004-6361/201833051 . Gaia DR2 record for this source at VizieR.
  3. 1 2 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.
  4. 1 2 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.
  5. 1 2 Gray, R. O.; Garrison, R. F. (December 1987), "The Early A-Type Stars: Refined MK Classification, Confrontation with Stroemgren Photometry, and the Effects of Rotation", Astrophysical Journal Supplement, 65: 581, Bibcode:1987ApJS...65..581G, doi: 10.1086/191237 .
  6. 1 2 de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, arXiv: 1208.3048 , Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, S2CID   59451347, A61.
  7. 1 2 3 4 5 6 Stassun, Keivan G.; et al. (2019), "The Revised TESS Input Catalog and Candidate Target List", The Astronomical Journal, 158 (4): 138, arXiv: 1905.10694 , Bibcode:2019AJ....158..138S, doi: 10.3847/1538-3881/ab3467 .
  8. 1 2 3 Freire Ferrero, R.; et al. (February 2012), "High Ionization Species in the Nearby Interstellar Medium from an Exhaustive Analysis of the IUE INES Database", The Astronomical Journal, 143 (2): 38, Bibcode:2012AJ....143...28F, doi: 10.1088/0004-6256/143/2/28 , 28.
  9. 1 2 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, S2CID   119108982.
  10. ↑ "HD 119921", SIMBAD , Centre de données astronomiques de Strasbourg , retrieved 2018-07-06.
  11. ↑ Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122 (6): 3466–3471, Bibcode:2001AJ....122.3466M, doi: 10.1086/323920 .
  12. ↑ Molaro, P.; Morossi, C.; Ramella, M.; Franco, M. (October 1983), "Superionization in the A0 V star HD 119921", Astronomy and Astrophysics, 127 (1): L3 –L4, Bibcode:1983A&A...127L...3M.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.