Theta Ursae Minoris

Theta Ursae Minoris

Theta in Ursa Minor.
Observation data Epoch J2000      Equinox J2000
Constellation	Ursa Minor
Right ascension	15^h 31^m 24.9^s[1]
Declination	+77° 20′ 58″[1]
Apparent magnitude (V)	5.00[1]
Characteristics
Spectral type	K5III
Astrometry
Radial velocity (Rv)	-25.30 ± 0.5 km/s
Proper motion (μ)	RA: -47.55 ± 0.37[2] mas/yr Dec.: 5.33 ± 0.43[2] mas/yr
Parallax (π)	3.81 ± 0.37[2] mas
Distance	860 ± 80 ly (260 ± 30 pc)
Details
Radius	4.8[3] R☉
Luminosity	1618[4] L☉
Temperature	4053 K[4] K
Other designations
15 Ursae Minoris, HR 5826, HD 139669, BD+77 592, FK5 3229, HIP 76008, SAO 8274.

Theta Ursae Minoris (θ UMi, θ Ursae Minoris) is a star in the constellation Ursa Minor. It is an orange giant of spectral type K5III with an apparent magnitude of +5.00. It is approximately 860 light years from Earth. Its diameter has been estimated as around 4.8 times that of the Sun,^[3] and its luminosity approximately 1618 times that of the Sun and has a surface temperature of 4053 K.^[4]

References

1. SIMBAD, Theta Ursae Minoris (accessed 16 June 2014)
2. van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357.
3. Pasinetti Fracassini, L. E.; Pastori, L.; Covino, S.; Pozzi, A. (February 2001). "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics". Astronomy and Astrophysics. 367: 521–24. arXiv:astro-ph/0012289. Bibcode:2001A&A...367..521P. doi:10.1051/0004-6361:20000451.
4. McDonald, I.; Zijlstra, A. A.; Boyer, M. L. (2012). "Fundamental Parameters and Infrared Excesses of Hipparcos Stars". Monthly Notices of the Royal Astronomical Society. 427 (1): 343–57. arXiv:1208.2037. Bibcode:2012MNRAS.427..343M. doi:10.1111/j.1365-2966.2012.21873.x.