Kappa Ursae Majoris
Binary star in the constellation Ursa Major / From Wikipedia, the free encyclopedia
Kappa Ursae Majoris (κ Ursae Majoris, abbreviated Kappa UMa, κ UMa) is a binary star in the constellation of Ursa Major. With a combined apparent magnitude of +3.60,[9] the system is approximately 358 light-years from Earth.
Quick Facts Constellation, Right ascension ...
Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Ursa Major |
Right ascension | 09h 03m 37.52762s[1] |
Declination | +47° 09′ 23.4890″[1] |
Apparent magnitude (V) | 3.56 (4.16 + 4.54)[2] |
Characteristics | |
Spectral type | A0 IV-V + A0 V[3] |
Astrometry | |
Proper motion (μ) | RA: −36.19[1] mas/yr Dec.: −55.40[1] mas/yr |
Parallax (π) | 9.10 ± 0.50 mas[1] |
Distance | 360 ± 20 ly (110 ± 6 pc) |
Absolute magnitude (MV) | −1.63[4] |
Orbit[5] | |
Period (P) | 13,007.2±9.7 d |
Semi-major axis (a) | 0.18194 ± 0.00025″ |
Eccentricity (e) | 0.5584±0.0015 |
Inclination (i) | 109.410±0.066° |
Longitude of the node (Ω) | 105.641±0.080° |
Periastron epoch (T) | 50404 ± 12 |
Argument of periastron (ω) (secondary) | 355.63±0.36° |
Details | |
κ UMa A | |
Mass | 3.79±0.12[6] M☉ |
Radius | 7.87[7] R☉ |
Temperature | 9,060[7] K |
Rotational velocity (v sin i) | 201[6] km/s |
Other designations | |
Database references | |
SIMBAD | data |
Close
The two components are designated Kappa Ursae Majoris A (officially named Alkaphrah /ælˈkæfrə/, a traditional name of the system)[10] and B.