Psi7 Aurigae

Psi⁷ Aurigae
	Location of ψ7 Aurigae (circled)
Observation data; Epoch J2000 Equinox J2000
Constellation	Auriga
Right ascension	06h 50m 45.94330s
Declination	+41° 46′ 52.4267″
Apparent magnitude (V)	5.02
Characteristics
Spectral type	K3 III
U−B color index	+1.35
B−V color index	+1.27
R−I color index	0.46
Astrometry
Radial velocity (Rv)	+59.53 ± 0.25 km/s
Proper motion (μ)	RA: –25.660 mas/yr ; Dec.: –138.163 mas/yr
Parallax (π)	9.8872 ± 0.1499 mas
Distance	330 ± 5 ly ; (101 ± 2 pc)
Absolute magnitude (MV)	−0.33
Details
Radius	24 R☉
Luminosity	217 L☉
Surface gravity (log g)	2.35 cgs
Temperature	4,300 K
Metallicity [Fe/H]	0.00 dex
Rotational velocity (v sin i)	10 km/s
Other designations
	ψ7 Aur, 58 Aurigae, BD+41 1536, FK5 2527, HD 49520, HIP 32844, HR 2516, SAO 41380.
Database references
SIMBAD	data

Psi⁷ Aurigae, Latinized from ψ⁷ Aurigae, is a star in the northern constellation of Auriga. It is a dim, naked eye star with an apparent visual magnitude of 5.02. Based upon Gaia Data Release 2 parallax values, it is approximately 330 light-years (100 parsecs) from Earth.

ψ⁷ Aurigae is a giant star with a stellar classification of K3 III.^[3] The measured angular diameter of this star, after correction for limb darkening, is 1.96 ± 0.04 mas.^[11] At its estimated distance,^[1] this yields a physical size of about 24 times the radius of the Sun.^[7] The outer envelope has an effective temperature of 4,300,^[8] giving it an orange colour and a classification as a K-type star.^[12] Although cooler than the sun, its larger size means that it is more luminous, emitting in total 217 times as much electromagnetic radiation.

It was also known to be part of a much bigger constellation named Telescopium Herschelii before it was unrecognized by the International Astronomical Union (IAU).

References

^ ^a ^b ^c 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 Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99): 99, Bibcode:1966CoLPL...4...99J
^ ^a ^b Roman, Nancy G. (July 1952), "The Spectra of the Bright Stars of Types F5-K5", Astrophysical Journal, 116: 122, Bibcode:1952ApJ...116..122R, doi:10.1086/145598.
^ Famaey, B.; et al. (January 2005), "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters", Astronomy and Astrophysics, 430 (1): 165–186, arXiv:astro-ph/0409579, Bibcode:2005A&A...430..165F, doi:10.1051/0004-6361:20041272, S2CID 17804304.
^ ^a ^b ^c Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
^ ^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.
^ ^a ^b Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library, vol. 1 (3rd ed.), Birkhäuser, ISBN 3-540-29692-1. The radius (R_*) is given by:
${\begin{aligned}2\cdot R_{*}&={\frac {(116\cdot 1.96\cdot 10^{-3})\ {\text{AU}}}{0.0046491\ {\text{AU}}/R_{\bigodot }}}\\&\approx 48.9\cdot R_{\bigodot }\end{aligned}}$
^ ^a ^b ^c ^d McWilliam, Andrew (December 1990), "High-resolution spectroscopic survey of 671 GK giants. I - Stellar atmosphere parameters and abundances", Astrophysical Journal Supplement Series, 74: 1075–1128, Bibcode:1990ApJS...74.1075M, doi:10.1086/191527.
^ Bernacca, P. L.; Perinotto, M. (1970), "A catalogue of stellar rotational velocities", Contributi Osservatorio Astronomico di Padova in Asiago, 239 (1): 1, Bibcode:1970CoAsi.239....1B.
^ "* 58 Aur". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2012-08-24.
^ Richichi, A.; Percheron, I.; Khristoforova, M. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics, 431 (2): 773–777, Bibcode:2005A&A...431..773R, doi:10.1051/0004-6361:20042039
^ "The Colour of Stars", Australia Telescope, Outreach and Education, Commonwealth Scientific and Industrial Research Organisation, December 21, 2004, archived from the original on March 18, 2012, retrieved 2012-01-16.