HD 105382

HD 105382

A light curve for V863 Centauri, plotted from Hipparcos data[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Centaurus
Right ascension 12h 08m 05.22401s[2]
Declination −50° 39′ 40.5728″[2]
Apparent magnitude (V) 4.47[3]
Characteristics
Spectral type B6III[4]
U−B color index −0.67[3]
B−V color index −0.15[3]
Variable type rotating variable[5]
Astrometry
Radial velocity (Rv)16.5[3] km/s
Proper motion (μ) RA: −35.16[2] mas/yr
Dec.: −6.47[2] mas/yr
Parallax (π)7.44 ± 0.61 mas[2]
Distance440 ± 40 ly
(130 ± 10 pc)
Absolute magnitude (MV)−1.2±0.3[4]
Absolute bolometric
magnitude (Mbol)		−2.9 ± 0.4[4]
Details
Mass5.7 ± 0.4[5] M☉
Radius3.0 ± 0.6[5] R☉
Luminosity1000+590
−370[4] L☉
Surface gravity (log g)4.18 ± 0.15[5] cgs
Temperature17400 ± 400[5] K
Rotation1.295 ± 0.001[5] days
Rotational velocity (v sin i)90[4] km/s
Other designations
CD−49°6813, HD 105382, HIP 59173, HR 4618, SAO 239687[3]
Database references
SIMBADdata

HD 105382 (also known as V863 Centauri) is a star in the constellation Centaurus. Its apparent magnitude is 4.47. From parallax measurements, it is located 130 parsecs (440 light years) from the Sun.

HD 105382 is a variable star whose apparent magnitude varies with an amplitude of 0.012 over a period of 1.295 days. It has been previously classified as a Be star, which would explain the variability as stellar pulsations, but this classification was probably due to accidental observation of the nearby Be star δ Centauri.[6] A 2004 study showed that the 1.295 day period is actually the rotation period of the star, and that the variability is caused by non-homogeneous distribution of elements in the stellar surface. In particular, HD 105382 is a helium-weak chemically peculiar star with a helium abundance varying between 0.5% and 15% of the solar abundance, and a silicon abundance varying between 0.00044% and 0.0069% the solar value. Regions with more helium appear to coincide with the regions with less silicon, and vice versa.[5] This peculiar abundance pattern is probably related to HD 105382's magnetic field,[5] which has a polar strength of 2.3 kG.[4]

From astrometric measurements by the Hipparcos spacecraft, HD 105382 is identified as a probable astrometric binary.[7] It is only 267" away from δ Centauri, and both stars appear to be at the same distance from Earth and have the same motion through space, so they may be related. In total, this may be a five star system.[8] It is a member of the Lower Centaurus–Crux (LCC) subgroup of the Scorpius–Centaurus association.[9]

  1. ^ Cite error: The named reference HipDataAccess was invoked but never defined (see the help page).
  2. ^ a b c d e Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  3. ^ a b c d e "HD 105382". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 25 October 2017.
  4. ^ a b c d e f Cite error: The named reference Petit2013 was invoked but never defined (see the help page).
  5. ^ a b c d e f g h Cite error: The named reference Briquet2004 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Briquet2001 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Makarov2005 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference deGeus1989 was invoked but never defined (see the help page).