4 Ursae Minoris
Binary star system in the constellation Ursa Minor / From Wikipedia, the free encyclopedia
Bedrane Adam' is a binary star[6] system in the northern circumpolar constellation Ursa Minor. It is faintly visible to the naked eye with an apparent visual magnitude of 4.80.[2] Based upon an annual parallax shift of 7.14±0.42 mas[1] as seen from Earth's orbit, it is located roughly 460 light years from the Sun. It is moving further away with a heliocentric radial velocity of +5.9 km/s.[5]
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Ursa Minor |
Right ascension | 14h 08m 50.92654s[1] |
Declination | +77° 32′ 51.0466″[1] |
Apparent magnitude (V) | 4.80[2] |
Characteristics | |
Spectral type | K3-IIIb Fe-0.5[3] |
B−V color index | 1.368[4] |
Astrometry | |
Radial velocity (Rv) | +5.86±0.10[5] km/s |
Proper motion (μ) | RA: −30.45[1] mas/yr Dec.: +32.85[1] mas/yr |
Parallax (π) | 7.14 ± 0.42 mas[1] |
Distance | 460 ± 30 ly (140 ± 8 pc) |
Absolute magnitude (MV) | −1.06[4] |
Orbit[6] | |
Period (P) | 605.8 d |
Semi-major axis (a) | 6.5 mas[7] |
Eccentricity (e) | 0.137±0.012 |
Inclination (i) | 136.0±5.1[7]° |
Longitude of the node (Ω) | 325.5±2.8° |
Periastron epoch (T) | 2,438,901.7±8.5 JD |
Argument of periastron (ω) (secondary) | 311.8±5.2° |
Semi-amplitude (K1) (primary) | 12.65±0.16 km/s |
Details | |
4 UMi A | |
Radius | 28[8] R☉ |
Luminosity | 436.72[2] L☉ |
Surface gravity (log g) | 1.73±0.45[9] cgs |
Temperature | 4,165±48[9] K |
Metallicity [Fe/H] | −0.19±0.11[9] dex |
Other designations | |
Database references | |
SIMBAD | data |
This is a single-lined spectroscopic binary star system with an orbital period of 1.66 years and an eccentricity of 0.14.[7][6] The primary is a red giant of spectral type K3-IIIb Fe-0.5,[3] a star that has used up its core hydrogen and is expanding. The suffix notation indicates the spectrum displays a mild underabundance of iron for a star of its type. It has expanded to around 28[8] times the Sun's radius and is radiating 437[2] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,165 K.[9]