Psi9 Aurigae

Psi⁹ Aurigae
	Location of ψ9 Aurigae (circled)
Observation data; Epoch J2000 Equinox J2000
Constellation	Auriga
Right ascension	06h 56m 32.05791s
Declination	+46° 16′ 26.3867″
Apparent magnitude (V)	5.75
Characteristics
Spectral type	B8 IIIe
U−B color index	–0.46
B−V color index	–0.06
Astrometry
Radial velocity (Rv)	–41.1 km/s
Proper motion (μ)	RA: –2.93 mas/yr ; Dec.: +4.07 mas/yr
Parallax (π)	2.59 ± 0.38 mas
Distance	approx. 1,300 ly ; (approx. 390 pc)
Absolute magnitude (MV)	−2.03
Details
Radius	3.7 R☉
Luminosity	868 L☉
Rotational velocity (v sin i)	235 km/s
Other designations
	ψ9 Aur, BD+46 1203, HD 50658, HIP 33377, HR 2568, SAO 41446
Database references
SIMBAD	data

Psi⁹ Aurigae, Latinised 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]

References

^ ^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, S2CID 18759600. Note: see VizieR catalogue I/311.
^ ^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 (2): 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451, S2CID 425754.
^ ^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.
^ ^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.
^ Wilson, Ralph Elmer (1953), "General Catalogue of Stellar Radial Velocities", Carnegie Institute Washington D.C. Publication, Washington: Carnegie Institution of Washington, Bibcode:1953GCRV..C......0W.
^ ^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, S2CID 119257644.
^ 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.
^ "* psi09 Aur". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2012-08-23.