φ1 Orionis
Orion constellation map.svg
Red circle.svg
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
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]


References

  1. ^ a b c d e f van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
  2. ^ a b c d Murdin, P.; Penston, M. V. (December 1977), "The Lambda Orionis association", Monthly Notices of the Royal Astronomical Society, 181 (4): 657–665, Bibcode:1977MNRAS.181..657M, doi:10.1093/mnras/181.4.657.
  3. ^ a b Levato, H. (January 1975), "Rotational velocities and spectral types for a sample of binary systems", Astronomy and Astrophysics Supplement Series, 19: 91–99, Bibcode:1975A&AS...19...91L.
  4. ^ Wilson, R. E. (1953), "General Catalogue of Stellar Radial Velocities", Carnegie Institute Washington D.C. Publication, Carnegie Institute of Washington, D.C., Bibcode:1953GCRV..C......0W.
  5. ^ a b Pourbaix, D.; et al. (2004), "SB9: The ninth catalogue of spectroscopic binary orbits", Astronomy & Astrophysics, 424 (2): 727–732, arXiv:astro-ph/0406573, Bibcode:2004A&A...424..727P, doi:10.1051/0004-6361:20041213, S2CID 119387088.
  6. ^ a b c d Nieva, María-Fernanda; Przybilla, Norbert (2014), "Fundamental properties of nearby single early B-type stars", Astronomy & Astrophysics, 566: A7, arXiv:1412.1418, Bibcode:2014A&A...566A...7N, doi:10.1051/0004-6361/201423373, S2CID 119227033.
  7. ^ Simón-Díaz, S.; Herrero, A. (2014), "The IACOB project. I. Rotational velocities in northern Galactic O- and early B-type stars revisited. The impact of other sources of line-broadening", Astronomy & Astrophysics, 562: A135, arXiv:1311.3360, Bibcode:2014A&A...562A.135S, doi:10.1051/0004-6361/201322758, S2CID 119278062.
  8. ^ a b Tetzlaff, N.; et al. (2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society, 410 (1): 190–200, arXiv:1007.4883, Bibcode:2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x, S2CID 118629873.
  9. ^ "phi01 Ori". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2016-11-29.((cite web)): CS1 maint: postscript (link)
  10. ^ O'Meara, Stephen James (2007), Deep-Sky Companions: Hidden Treasures, Cambridge University Press, p. 146, ISBN 978-1139463737.
  11. ^ Hernández, Jesús; Calvet, Nuria; Hartmann, L.; Muzerolle, J.; Gutermuth, R.; Stauffer, J. (December 2009), "Spitzer Observations of the λ Orionis Cluster. I. The Frequency of Young Debris Disks at 5 Myr", The Astrophysical Journal, 707 (1): 705–715, arXiv:0910.3884, Bibcode:2009ApJ...707..705H, doi:10.1088/0004-637X/707/1/705, S2CID 17546989.