V831 Centauri

V831 Centauri

A light curve for V831 Centauri, plotted from Hipparcos data[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Centaurus
Right ascension 13h 12m 17.59459s[2]
Declination −59° 55′ 14.0842″[2]
Apparent magnitude (V) 4.58[3] (4.49 to 4.66)[4]
Characteristics
Spectral type B7V[5] (B8V + ? + B9V)[6]
B−V color index −0.073±0.007[3]
Variable type Rotating ellipsoidal[4]
Astrometry
Radial velocity (Rv)+12.0±3.7[3] km/s
Proper motion (μ) RA: −29.71[2] mas/yr
Dec.: −17.40[2] mas/yr
Parallax (π)8.61 ± 0.85 mas[2]
Distance380 ± 40 ly
(120 ± 10 pc)
Absolute magnitude (MV)−0.72[3]
Orbit[7]
PrimaryA
CompanionB
Period (P)27.2±0.4 yr
Semi-major axis (a)180±20 mas
Eccentricity (e)0.48±0.1
Inclination (i)62.2±2.0°
Longitude of the node (Ω)−104±5°
Periastron epoch (T)1887.2±0.6
Argument of periastron (ω)
(secondary)		219±5°
Orbit[7]
PrimaryAB
CompanionC
Period (P)~2,000 yr
Semi-major axis (a)3.2±0.1″
Eccentricity (e)0.5
Inclination (i)68°
Longitude of the node (Ω)−85°
Periastron epoch (T)1084.5±3.0
Details[7]
Aa
Mass4.08±0.07 M☉
Radius2.38±0.03 R☉
Luminosity261.12[3] L☉
Temperature13,000±300 K
Rotational velocity (v sin i)194 km/s
Ab
Mass3.35±0.06 M☉
Radius2.25±0.03 R☉
Temperature11,800±300 K
Rotational velocity (v sin i)170 km/s
Age18±3 Myr
B
Mass2.5 M☉
C
Mass1.5 M☉
Other designations
V831 Cen, CD−59°4614, GC 17866, HD 114529, HIP 64425, HR 4975, SAO 240645, WDS J13123-5955[8]
Database references
SIMBADdata

V831 Centauri is a multiple[6] star system in the constellation Centaurus. It is visible to the naked eye with an apparent visual magnitude that ranges from 4.49 down to 4.66.[4] The system is located at a distance of approximately 380 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +12 km/s.[3] It is a likely member of the Lower Centaurus Crux concentration of the Sco OB2 association of co-moving stars.

The magnitude 5.3 primary component forms a near-contact binary system, with the components designated Aa and Ab. It has a combined class of B8V, an orbital period of 0.6425251 d, a separation of 6 R☉, and both components are close to co-rotating with their orbit. The larger member has 4.1 times the mass of the Sun and 2.4 times the Sun's radius, while the companion has 3.4 and 2.3 times, respectively. The pair form an eclipsing system,[7] and it is classed as a rotating ellipsoidal variable.[4]

The third star, component B, is magnitude 6.0 and forms a visual pair, designated See 170, with the inner system. They orbit each other with a period of 27.2 years and an eccentricity of 0.5. This star has a mass about 2.5 times that of the Sun and may be an Ap star. The fourth member, component C, orbits the system with a period of around 2,000 years. There is a fifth member, component D.[7]

  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 f Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  4. ^ a b c d Cite error: The named reference Samus2017 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference houk1979 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  7. ^ a b c d e Cite error: The named reference Budding2010 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).