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Pi Ursae Minoris is a common proper motion binary star system in the northern circumpolar constellation of Ursa Minor. The pair have apparent visual magnitudes of +6.58 and +7.31, with a combined magnitude of 6.1. They are located about 71 light years from the Sun. The two have an angular separation of 31.4 arc seconds, which corresponds to a physical separation of about 680 AU, and orbit each other with a period of about 13,100 years.

Both stars are solar analogs and have been listed as possible members of the Hercules-Lyra association, one of the nearest moving groups to the Sun, although this is now considered unlikely. The primary, π Ursae Minoris A, has a mass 2% higher than the sun, an almost identical effective temperature at 5,771 K, a radius 98% of the sun's, and a bolometric luminosity 93% of the sun's. The secondary, π Ursae Minoris B, has a mass 92% of the sun's, a slightly lower temperature of 5,408 K, a radius 84% of the sun's, and a luminosity slightly over half of the sun.

References

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2. ^ Johnson, Harold L. (May 1953), "Photoelectric Observations of Visual Double Stars.", Astrophysical Journal, 117: 361, Bibcode:1953ApJ...117..361J, doi:10.1086/145700.
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8. ^ 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.
9. ^ Tokovinin, Andrei (2014), "From Binaries to Multiples. II. Hierarchical Multiplicity of F and G Dwarfs", The Astronomical Journal, 147 (4): 14, arXiv:1401.6827, Bibcode:2014AJ....147...87T, doi:10.1088/0004-6256/147/4/87, S2CID 56066740, 87.
10. ^ Mishenina, T. V.; et al. (April 2013), "Abundances of neutron-capture elements in stars of the Galactic disk substructures", Astronomy & Astrophysics, 552: 12, arXiv:1303.1730, Bibcode:2013A&A...552A.128M, doi:10.1051/0004-6361/201220687, S2CID 119268097, A128.
11. ^ Casagrande, L.; et al. (2011), "New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey", Astronomy & Astrophysics, 530 (A138): 21, arXiv:1103.4651, Bibcode:2011A&A...530A.138C, doi:10.1051/0004-6361/201016276, S2CID 56118016.
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13. "** STF 1972AB". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-06-26.{{cite web}}: CS1 maint: postscript (link)
    • HD 139777 -- High proper-motion Star
    • HD 139813 -- High proper-motion Star
14. Kepple, George Robert; Sanner, Glen W. (1998), The Night Sky Observers Guide: Spring & summer, vol. 2, Willmann-Bell, p. 418, ISBN 0943396603.
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External links

• The Electronic Sky
• University of Florida Astronomy Department
• HR 1971
• Image Omicron Aurigae

v t e Constellation of Ursa Minor
List of stars in Ursa Minor Ursa Minor in Chinese astronomy
Stars	Bayer α (Polaris) β (Kochab) γ (Pherkad) δ (Yildun) ε ζ η θ λ π π Flamsteed 3 4 5 6 8 (Baekdu) 9 10 11 (γ) 12 14 17 19 20 24 Variable R S T U V W Z RR RU RW SS UY VX HR 5184 5596 HD 150706 Other Calvera H1504+65 LP 40-365 WD 1337+705 WISE 1506+7027
Exoplanets β Ursae Minoris b 8 Ursae Minoris b (Halla) 11 Ursae Minoris b TOI-4138 b
Galaxies	NGC 5034 5144 5939 6217 6251 6331 Other 3C 309.1
Galaxy clusters Abell 2256
Category

• G-type main-sequence stars
• Binary stars
• Bayer objects
• Ursa Minor
• Durchmusterung objects
• Henry Draper Catalogue objects
• Hipparcos objects
• Bright Star Catalogue objects