Xi Orionis

ξ Orionis
Location of ξ Orionis (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Orion
Right ascension 06h 11m 56.39693s[1]
Declination +14° 12′ 31.5555″[1]
Apparent magnitude (V) 4.47[2]
Characteristics
Spectral type B3 IV[3]
U−B color index −0.65[2]
B−V color index −0.19[2]
Astrometry
Radial velocity (Rv)+19.30[4] km/s
Proper motion (μ) RA: +0.29[1] mas/yr
Dec.: −20.12[1] mas/yr
Parallax (π)5.37 ± 0.23 mas[1]
Distance610 ± 30 ly
(186 ± 8 pc)
Orbit[5]
Period (P)45.1 d
Eccentricity (e)0.26
Periastron epoch (T)2,441,962.3 JD
Argument of periastron (ω)
(secondary)		205°
Semi-amplitude (K1)
(primary)		22.4 km/s
Details
ξ Ori A
Mass6.7±0.1[3] M☉
Luminosity1,390[6] L☉
Temperature15,476[6] K
Rotational velocity (v sin i)160[7] km/s
Age32.1±4.3[3] Myr
Other designations
ξ Ori, 70 Orionis, BD+14° 1187, HD 42560, HIP 29426, HR 2199, SAO 95362[8]
Database references
SIMBADdata

Xi Orionis (ξ Orionis) is a binary star system in the northeastern part of the constellation of Orion, well above the red giant star Betelgeuse in the sky. It lies next to another blue main-sequence star, Nu Orionis, which is somewhat closer at 520 light-years' distance. The apparent visual magnitude of Xi Orionis is 4.47,[2] which is bright enough to be seen with the naked eye. The distance to this star, as determined using the parallax method, is roughly 610 light-years.[1]

This is a spectroscopic binary star system with an orbital period of 45.1 days and an eccentricity of 0.26.[5] The primary component is a B-type subgiant star with a stellar classification of B3 IV.[3] With an estimated age of just 32 million years,[3] it has a relatively high rate of spin, showing a projected rotational velocity of 160 km/s.[7] Xi Orionis has about 6.7 times the mass of the Sun,[3] and shines with 1,390 times the solar luminosity from its outer atmosphere at an effective temperature of 15,476 K.[6]

  1. ^ a b c d e f Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference Crawford1971 was invoked but never defined (see the help page).
  3. ^ a b c d e f Cite error: The named reference Tetzlaff2011 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference deBruijne2012 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference pourbaix2004 was invoked but never defined (see the help page).
  6. ^ a b c Cite error: The named reference Mcdonald2012 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Abt2002 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).