Phi1 Orionis

φ1 Orionis
φ1 (circled) in the constellation Orion
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Orion
Right ascension 05h 34m 49.23804s[1]
Declination +09° 29′ 22.4878″[1]
Apparent magnitude (V) 4.42[2]
Characteristics
Spectral type B0 III[3]
U−B color index −0.97[2]
B−V color index −0.15[2]
Astrometry
Radial velocity (Rv)+33.2[4] km/s
Proper motion (μ) RA: +0.27[1] mas/yr
Dec.: −2.26[1] mas/yr
Parallax (π)3.00 ± 0.25 mas[1]
Distance1,090 ± 90 ly
(330 ± 30 pc)
Absolute magnitude (MV)−3.53±0.30
Orbit[5]
Period (P)3,068.03 d
Eccentricity (e)0.22
Periastron epoch (T)2418051.8 JD
Argument of periastron (ω)
(secondary)
105°
Semi-amplitude (K1)
(primary)
13.3 km/s
Details[6]
Mass15.5±1.1 M
Radius6.3±1.0 R
Luminosity28,840 L
Surface gravity (log g)4.05±0.10 cgs
Temperature30,000±300 K
Rotational velocity (v sin i)20[7] km/s
Age7.2±0.8[8] Myr
Other designations
φ1 Ori, 37 Orionis, BD+09° 877, FK5 208, HD 36822, HIP 26176, HR 1876, SAO 112914.[9]
Database references
SIMBADdata
φ1 Orionis with nebulosity west of φ2 Orionis and south of λ Orionis

Phi1 Orionis is a binary star system in the constellation Orion, positioned less than a degree to the south of Meissa.[10] It is visible to the naked eye with an apparent visual magnitude of 4.42.[2] The distance to this system, based upon an annual parallax shift of 3.0 mas,[1] is around 1,090 light-years.

This is a single-lined[6] spectroscopic binary star system with an orbital period of 3,068 days and an eccentricity of 0.22.[5] It is a member of the young Lambda Orionis cluster[11] and is roughly 7 million years old.[8] The primary component is a B-type giant star with a stellar classification of B0 III.[3] It has over 15 times the mass of the Sun and around 6.3 times the Sun's radius.[6] Nothing is known about the secondary companion. It does not contribute a significant amount of light to the combined spectrum.[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 murdin1977 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Levato1975 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference gcrv1953 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 d Cite error: The named reference nieva2014 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference simon-diaz2014 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference tetzlaff2011 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference OMeara2007 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Hernandez2009 was invoked but never defined (see the help page).