Mu1 Boötis
Location of μ1 Boötis (circled) | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Boötes |
| Right ascension | 15h 24m 29.43147s |
| Declination | +37° 22′ 37.7613″ |
| Apparent magnitude (V) | 4.31 |
| Characteristics | |
| Spectral type | F2IV |
| U−B color index | +0.06 |
| B−V color index | +0.31 |
| R−I color index | 0.15 |
| Astrometry | |
| Radial velocity (Rv) | −8.60±0.3 km/s |
| Proper motion (μ) | RA: −149.928 mas/yr Dec.: +89.573 mas/yr |
| Parallax (π) | 26.5759±0.7871 mas |
| Distance | 123 ± 4 ly (38 ± 1 pc) |
| Absolute magnitude (MV) | 1.47 |
| Orbit | |
| Primary | Aa |
| Name | Ab |
| Period (P) | 3.75 years |
| Semi-major axis (a) | 0.099″ |
| Eccentricity (e) | 0.270 |
| Inclination (i) | 129.7° |
| Longitude of the node (Ω) | 129.4° |
| Periastron epoch (T) | 1006.33 |
| Argument of periastron (ω) (secondary) | 43.5° |
| Details | |
| Aa | |
| Mass | 1.6 M☉ |
| Radius | 1.9 R☉ |
| Luminosity | 20 L☉ |
| Surface gravity (log g) | 3.4 cgs |
| Temperature | 7,000 K |
| Rotational velocity (v sin i) | 89 km/s |
| Ab | |
| Mass | 1.5 M☉ |
| Surface gravity (log g) | 3.6 cgs |
| Temperature | 7,000 K |
| Rotational velocity (v sin i) | 40 km/s |
| Other designations | |
| Alkalurops, Inkalunis, Icalurus, Clava, Venabulum, μ Boo, 51 Boötis A, BD+37°2636, FK5 568, GC 20724, GJ 3903, HD 137391, HIP 75411, HR 5733, SAO 64686, ADS 9626, CCDM 15245+3722 | |
| Database references | |
| SIMBAD | data |
Mu1 Boötis is a binary star in the northern constellation of Boötes. Its name is a Bayer designation that is Latinized from μ1 Boötis, and abbreviated Mu1 Boo or μ1 Boo. This system had the traditional name Alkalurops, pronounced /ælkəˈljʊərɒps/. Based on parallax measurements, the system is located at a distance of 123 light-years.
The components of the system have an angular separation of 0.10″. They form a spectroscopic binary system with an orbital period of 3.75 years. The visible component is a yellow-white F-type subgiant with an apparent magnitude of +4.31.
The system μ2 Boötis, separated by 109", makes an optical double with μ1, and even has a similar distance from Earth and comparable proper motions, but has a substantially different metallicity, and therefore is not a gravitationally bound companion.