Chi Ursae Majoris

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Chi Ursae Majoris
Location of χ Ursae Majoris (circled)
Observation data
ICRS
)
Constellation Ursa Major
Right ascension 11h 46m 3.01407s[1]
Declination +47° 46′ 45.8626″[1]
Apparent magnitude (V) 3.72[2]
Characteristics
Evolutionary stage Horizontal branch[3]
Spectral type K0.5 IIIb[4]
U−B color index +1.16[2]
B−V color index +1.18[2]
Distance
184 ± 2 ly
(56.3 ± 0.5 pc)
Absolute magnitude (MV)0.10±0.02[5]
Details
Rotational velocity
(v sin i)
2.3 km/s
HR 4518, SAO 43886[9]
Database references
SIMBADdata

Chi Ursae Majoris or χ Ursae Majoris, formally named Taiyangshou

apparent visual magnitude of 3.72.[2] It is located at a distance of approximately 184 light-years from the Sun based on parallax, but is drifting closer with a radial velocity of −9 km/s.[2]

Nomenclature

Chi Ursae Majoris and NGC 3877

χ Ursae Majoris (Latinised to Chi Ursae Majoris) is the star's Bayer designation.

It bore the

Purple Forbidden enclosure (see : Chinese constellations). It also bore traditional names of Arabic origin: Alkafzah, Alkaphrah, and El Koprah.[8]

In 2016, the IAU organized a Working Group on Star Names (WGSN)[13] to catalog and standardize proper names for stars. The WGSN approved the name Taiyangshou for this star on 30 June 2017 and it is now so included in the List of IAU-approved Star Names.[10]

Properties

Chi Ursae Majoris is an

helium fusion at its core. This star has expanded to 20.8±0.8[7] times the radius of the Sun with 1.49 times the Sun's mass.[6] It is radiating 158 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,416 K.[2]

The spiral galaxy in Ursa Major, NGC 3877 (= H I.201), type Sc, is best found from Chi Ursae Majoris, which is almost exactly 15 arcminutes north of the galaxy.

References

External links