HD 119921

This article is about z Centauri. Not to be confused with the supernovae SN 1895B associated with a variable star given Bayer designation of "Z Centauri".
HD 119921
Observation data
Epoch J2000      Equinox J2000
Constellation Centaurus
Right ascension 13h 46m 56.35149s[1]
Declination –36° 15′ 06.9563″[1]
Apparent magnitude (V) 5.15[2]
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[1] mas/yr
Dec.: −11.115[1] mas/yr
Parallax (π)7.7881 ± 0.2382 mas[1]
Distance420 ± 10 ly
(128 ± 4 pc)
Absolute magnitude (MV)0.93[7]
Details
Luminosity125.24[8] L☉
Temperature8,801[8] K
Rotational velocity (v sin i)220[9] km/s
Age337[7] Myr
Other designations
z Cen, CD−35°8995, FK5 3091, HD 119921, HIP 67244, HR 5174, SAO 204835, WDS J13469-3615A[10]
Database references
SIMBADdata

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.[2] 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.[7]

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.[9] The star is radiating around 125 times the Sun's luminosity from its photosphere at an effective temperature of 8,801 K.[8]

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.[9]

  1. ^ a b c d e Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference houk1979 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Gray1987 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference deBruijne2012 was invoked but never defined (see the help page).
  7. ^ a b c Cite error: The named reference Gontcharov2012 was invoked but never defined (see the help page).
  8. ^ a b c Cite error: The named reference McDonald2012 was invoked but never defined (see the help page).
  9. ^ a b c Cite error: The named reference Ferrero2012 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference WDSC2014 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Molaro1983 was invoked but never defined (see the help page).