Pi1 Ursae Minoris

{{Short description|Common proper motion binary star in the constellation Ursa Minor}}

{{other stars by Bayer designation|Pi Ursae Minoris{{!}}π Ursae Minoris}}

{{Starbox begin

| name = π¹ Ursae Minoris

}}

{{Starbox observe 2s

| epoch = J2000.0

| equinox = J2000.0 (ICRS)

| constell = Ursa Minor

| component1 = π¹ UMi A

| ra1 = {{RA|15|29|11.18599}}

| dec1 = {{DEC|+80|26|54.9713}}

| appmag_v1 = +6.58

| component2 = π¹ UMi B

| ra2 = {{RA|15|29|23.59426}}

| dec2 = {{DEC|+80|27|00.9675}}

| appmag_v2 = +7.31

}}

{{Starbox character

| component1 = π¹ UMi A

| class = G1.5 V(n)

| b-v = +0.67

| u-b = +0.13

| variable =

| component2 = π¹ UMi B

| class2 = G9 V

| b-v2 = +0.79

| u-b2 = +0.37

}}

{{Starbox astrometry

| component1 = π¹ UMi A

| radial_v = {{Val|−16.27|0.09}}

| prop_mo_ra = −225.109

| prop_mo_dec = +107.575

| parallax = 45.8577

| p_error = 0.0328

| parallax_footnote =

| absmag_v = {{Val|4.94|0.04}}

| component2 = π¹ UMi B

| radial_v2 = {{Val|−15.40|0.70}}

| prop_mo_ra2 = −217.817

| prop_mo_dec2 = +105.947

| parallax2 = 45.8038

| p_error2 = 0.0352

| parallax_footnote2 =

| absmag_v2 =

}}

{{Starbox detail

| source =

| component1 = π¹ UMi A

| mass = 1.02

| radius = 0.98

| luminosity = 0.929

| temperature = 5,771

| gravity = 4.40

| metal_fe = −0.22

| rotational_velocity =

| age_gyr = {{Val|9.22|3.84}}

| component2 = π¹ UMi B

| mass2 = 0.92

| radius2 = 0.84

| luminosity2 = 0.520

| temperature2 = 5,408

| gravity2 = 4.50

| metal2_fe = −0.18

}}

{{Starbox catalog

| names = {{odlist | B=π¹ UMi | ADS=9696 | WDS=J15292+8027 }}

| component1 = π¹ UMi A

| names1 = {{odlist | BD=+80°480 | FK5= | HD=139777 | HIP=75809 | HR=5829 | SAO=2556 }}

| component2 = π¹ UMi B

| names2 = {{odlist | BD=+80°481 | FK5= | HD=139813 | HIP=75829 | HR= | SAO=2558 }}

}}

{{Starbox reference

| Simbad = **+STF+1972AB | sn = π¹ UMi AB

| Simbad2 = HD+139777 | sn2 = π¹ UMi A

| Simbad3 = HD+139813 | sn3 = π¹ UMi B

}}

Pi¹ 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, π¹ Ursae Minoris A, has a mass 2% higher than the sun, an almost identical effective temperature at {{val|5,771|fmt=commas|ul=K}}, a radius 98% of the sun's, and a bolometric luminosity 93% of the sun's. The secondary, π¹ Ursae Minoris B, has a mass 92% of the sun's, a slightly lower temperature of {{val|5,408|fmt=commas|u=K}}, a radius 84% of the sun's, and a luminosity slightly over half of the sun.

References

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{{cite simbad

| title=** STF 1972AB | accessdate=2017-06-26 | postscript=. }}

[https://simbad.u-strasbg.fr/simbad/sim-id?Ident=HD+139777 HD 139777 -- High proper-motion Star ]
[https://simbad.u-strasbg.fr/simbad/sim-id?Ident=HD+139813 HD 139813 -- High proper-motion Star ]

}}

External links

[http://www.glyphweb.com/esky/default.htm?http://www.glyphweb.com/esky/stars/omicronaurigae.html The Electronic Sky]
[https://web.archive.org/web/20060417075020/http://www.astro.ufl.edu/~cohen/ast1002/table_19.html University of Florida Astronomy Department]
[http://webviz.u-strasbg.fr/viz-bin/VizieR-S?HR%201971 HR 1971]
[http://aladin.u-strasbg.fr/AladinPreview?-c=05+45+54.0387%2B49+49+34.519&ident=*+omi+Aur&submit=Aladin+previewer Image Omicron Aurigae]

Category:G-type main-sequence stars

Category:Binary stars

Ursae Minoris, Pi

Category:Ursa Minor

Category:Durchmusterung objects

139777 139813

75809 75829

5829