36 Ursae Majoris

36 Ursae Majoris
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Ursa Major
A
Right ascension 10h 30m 37.5793s[1]
Declination +55° 58′ 49.940″[1]
Apparent magnitude (V) 4.82[2]
B
Right ascension 10h 30m 25.3089s[3]
Declination +55° 59′ 56.855″[3]
Apparent magnitude (V) 8.86[4]
Characteristics
A
Evolutionary stage main sequence
Spectral type F8 V[5]
U−B color index −0.01[2]
B−V color index +0.52[2]
B
Evolutionary stage main sequence
Spectral type K7Ve[6]
B−V color index +1.34[7]
Astrometry
A
Radial velocity (Rv)+8.57[1] km/s
Proper motion (μ) RA: −177.045[1] mas/yr
Dec.: −32.634[1] mas/yr
Parallax (π)77.2485 ± 0.0805 mas[1]
Distance42.22 ± 0.04 ly
(12.95 ± 0.01 pc)
Absolute magnitude (MV)4.29[8]
B
Radial velocity (Rv)+8.67[3] km/s
Proper motion (μ) RA: −182.443[3] mas/yr
Dec.: −32.034[1] mas/yr
Parallax (π)77.4072 ± 0.0182 mas[3]
Distance42.135 ± 0.010 ly
(12.919 ± 0.003 pc)
Absolute magnitude (MV)8.2[7]
Details
A
Mass1.10[1] M☉
Radius1.17[1] R☉
Luminosity1.69[1] L☉
Surface gravity (log g)4.4.23[1] cgs
Temperature6,066[1] K
Metallicity [Fe/H]−0.09[9] dex
Rotational velocity (v sin i)1.50[9] km/s
Age4.0[1] Gyr
B
Mass0.626[4] M☉
Radius0.648[4] R☉
Luminosity0.10[10] L☉
Surface gravity (log g)4.61[4] cgs
Temperature4,132[10] K
Metallicity [Fe/H]−0.08[10] dex
Rotational velocity (v sin i)9[11] km/s
Age5[12] Gyr
Other designations
36 Ursae Majoris, WDS J10306+5559[5]
A: BD+56°1459, FK5 394, HD 90839, HIP 51459, HR 4112, SAO 27670
B: BD+56°1458, HD 237903, SAO 27668
Database references
SIMBADA
B

36 Ursae Majoris is a double star[5] in the northern constellation of Ursa Major. With an apparent visual magnitude of 4.8, it can be seen with the naked eye in suitable dark skies. Based upon parallax measurements, this binary lies at a distance of 42 light-years (13 parsecs) from Earth.

The brighter star of the two is a solar analog—meaning it has physical properties that make it similar to the Sun. It has 10% more mass and a radius 17% larger than the Sun, with an estimated age of four billion years. The spectrum of this star matches a stellar classification of F8 V, which indicates this is a main sequence star that is generating energy at its core through the nuclear fusion of hydrogen. The energy is being radiated into space from its outer envelope at an effective temperature of 6,066 K. This gives the star the characteristic yellow-white hue of an F-type star.[13]

The fainter of the two stars has an apparent magnitude 8.86 and shares a common proper motion witIts spectral type of K7Ve indicates it is a red dwarf. Its has a mass 60% of the Sun's, a temperature of 4,132 K and a bolometric luminosity only 10% of the Sun's.

36 Ursae Majoris has a second companion with a magnitude of 11.44 located at an angular separation of 240.6″ along a position angle of 292°, as of 2004.[14] It does not share the proper motion of the other two stars and is a more massive and luminous star but much further away.[15]

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  2. ^ a b c Cite error: The named reference clpl4_99 was invoked but never defined (see the help page).
  3. ^ a b c d e Cite error: The named reference dr3b was invoked but never defined (see the help page).
  4. ^ a b c d Cite error: The named reference ticv8 was invoked but never defined (see the help page).
  5. ^ a b c Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference ds2018 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference borosaikia2018 was invoked but never defined (see the help page).
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  9. ^ a b Cite error: The named reference chavero2021 was invoked but never defined (see the help page).
  10. ^ a b c Cite error: The named reference gaidos2014 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference lv2019 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference ry2019 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference csiro was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference WDSC2014 was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference dr3c was invoked but never defined (see the help page).