Iota1 Librae
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Libra |
| Right ascension | 15h 12m 13.29025s |
| Declination | −19° 47′ 30.1592″ |
| Apparent magnitude (V) | +4.54 (5.1 + 5.6 + 10.4 + 10.9) |
| Characteristics | |
| Evolutionary stage | Blue subgiant |
| Spectral type | B9IVpSi + B9 + G5IV |
| U−B color index | −0.38 |
| B−V color index | −0.08 |
| Variable type | Alpha2 Canum Venaticorum |
| Astrometry | |
| Radial velocity (Rv) | −11.6 km/s |
| Proper motion (μ) | RA: −35.40 mas/yr Dec.: −32.79 mas/yr |
| Parallax (π) | 8.59±0.25 mas |
| Distance | 380 ± 10 ly (116 ± 3 pc) |
| Absolute magnitude (MV) | −0.79 |
| Position (relative to A) | |
| Component | BC |
| Angular distance | 57.8″ |
| Position angle | 111° |
| Orbit | |
| Primary | Aa |
| Name | Ab |
| Period (P) | 8163.16 d |
| Semi-major axis (a) | 0.129″ |
| Eccentricity (e) | 0.35 |
| Inclination (i) | 154.20° |
| Periastron epoch (T) | 2433155 JD |
| Argument of periastron (ω) (secondary) | 7.6° |
| Semi-amplitude (K1) (primary) | 3.4 km/s |
| Position (relative to B) | |
| Component | C |
| Angular distance | 2.058″ |
| Position angle | 111° |
| Details | |
| Aa | |
| Mass | 3.61 M☉ |
| Ab | |
| Mass | 3.12 M☉ |
| B | |
| Mass | 0.98 M☉ |
| C | |
| Mass | 0.91 M☉ |
| Other designations | |
| ι1 Lib, 24 Librae, BD−19°4047, HD 134759, HIP 74392, HR 5652, SAO 159090, WDS J15122-1948A | |
| Database references | |
| SIMBAD | data |
Iota1 Librae is a quadruple star system in the constellation Libra. Its name is a Bayer designation that is Latinized from ι1 Librae, and abbreviated Iota1 Lib or ι1 Lib. Its apparent magnitude is 4.54. It is located 379 light years from earth.