Psi9 Aurigae

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Psi9 Aurigae
Auriga constellation map.svg
Red circle.svg
Location of ψ9 Aurigae (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Auriga
Right ascension  06h 56m 32.05791s[1]
Declination +46° 16′ 26.3867″[1]
Apparent magnitude (V) 5.75[2]
Spectral type B8 IIIe[3]
U−B color index –0.46[4]
B−V color index –0.06[4]
Radial velocity (Rv)–41.1[5] km/s
Proper motion (μ) RA: –2.93[1] mas/yr
Dec.: +4.07[1] mas/yr
Parallax (π)2.59 ± 0.38[1] mas
Distanceapprox. 1,300 ly
(approx. 390 pc)
Absolute magnitude (MV)−2.03[6]
Radius3.7[2] R
Luminosity868[6] L
Rotational velocity (v sin i)235[7] km/s
Other designations
ψ9 Aur, BD+46 1203, HD 50658, HIP 33377, HR 2568, SAO 41446.[8]
Database references

Psi9 Aurigae, Latinized from ψ9 Aurigae, is a star in the northern constellation of Auriga, it is dimly visible to the naked eye with an apparent visual magnitude of 5.75.[2] Based upon an annual parallax shift of 2.59 mas,[1] the distance to this star is approximately 1,300 light-years (400 parsecs).

The spectrum of Psi9 Aurigae matches a giant star with a stellar classification of B8 IIIe;[3] the 'e' suffix indicates this is a Be star that shows emission lines of hydrogen in its spectrum. This is caused by a circumstellar shell of hot gas; the emission undergoes variability on a time scale of sixteen years.[3]


  1. ^ a b c d e f van Leeuwen, Floor (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752v1, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357. Note: see VizieR catalogue I/311.
  2. ^ a b c Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics", Astronomy and Astrophysics, 367: 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451.
  3. ^ a b c Ghosh, K. K. (September 1989), "Search for rapid spectral variability in Psi(9) Aurigae", Publications of the Astronomical Society of the Pacific, 101: 839–843, Bibcode:1989PASP..101..839G, doi:10.1086/132504.
  4. ^ a b Crawford, D. L. (February 1963), "U, b, v, and Hβ Photometry for the Bright B8- and B9-TYPE Stars", Astrophysical Journal, 137: 530, Bibcode:1963ApJ...137..530C, doi:10.1086/147526.
  5. ^ Wilson, Ralph Elmer (1953), General Catalogue of Stellar Radial Velocities, Washington: Carnegie Institution of Washington, Bibcode:1953GCRV..C......0W.
  6. ^ a b Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015.
  7. ^ Abt, Helmut A.; Levato, Hugo; Grosso, Monica (July 2002), "Rotational Velocities of B Stars", The Astrophysical Journal, 573 (1): 359–365, Bibcode:2002ApJ...573..359A, doi:10.1086/340590.
  8. ^ "* psi09 Aur". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2012-08-23.

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