Alkaphrah
Double star Alkaphrah (κ UMa A) |
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AladinLite | |||||||||||||||||||
Observation dates equinox : J2000.0 , epoch : J2000.0 |
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Constellation | Big Bear | ||||||||||||||||||
Right ascension | 09 h 03 m 37.53 s | ||||||||||||||||||
declination | + 47 ° 09 ′ 23.5 ″ | ||||||||||||||||||
Apparent brightness | 3.55 mag | ||||||||||||||||||
Typing | |||||||||||||||||||
B − V color index | +0.00 | ||||||||||||||||||
U − B color index | +0.01 | ||||||||||||||||||
R − I index | +0.01 | ||||||||||||||||||
Spectral class | A1 Vn | ||||||||||||||||||
Astrometry | |||||||||||||||||||
Radial velocity | (4.4 ± 2) km / s | ||||||||||||||||||
parallax | (9.10 ± 0.50) mas | ||||||||||||||||||
distance | (358 ± 20) ly (109.9 ± 6.0) pc |
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Visual absolute brightness M vis | −1.63 mag | ||||||||||||||||||
Proper movement | |||||||||||||||||||
Rec. Share: | (−36.19 ± 0.48) mas / a | ||||||||||||||||||
Dec. portion: | (−55.40 ± 0.32) mas / a | ||||||||||||||||||
Physical Properties | |||||||||||||||||||
Other names and catalog entries |
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Alkaphrah (and spelling of the IAU ), also Kappa Ursae Majoris , κ Ursae Majoris or κ UMa ( Bayer designation ), an about 360 light-years from the sun distant double star in the constellation Big Dipper (Ursa Major) with a common apparent brightness of 3, 55 likes.
Both components A and B of the system κ Ursae Majoris are main sequence stars of the spectral class A. They have magnitudes of 4.16 mag (κ UMa A = Alkaphrah) and 4.54 mag (κ UMa B) and have one Angular spacing of approx. 0.3 arc seconds .
The proper name Alkaphra goes back to the Arabic Al Ḳafzah "the jump". Another name for the star is Talitha Australis ; the Arabic Thalita means "third (leap of the gazelle)", the Latin australis means "south". Talitha Borealis (from Latin borealis "north") is the corresponding name for the neighboring star Iota Ursae Majoris .