49 Librae
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Libra |
| Right ascension | 16h 00m 19.61087s |
| Declination | −16° 32′ 00.5483″ |
| Apparent magnitude (V) | 5.47 |
| Characteristics | |
| 49 Lib Aa | |
| Evolutionary stage | Blue straggler |
| Spectral type | F8 V |
| U−B color index | +0.03 |
| B−V color index | +0.52 |
| 49 Lib Ab | |
| Evolutionary stage | White dwarf |
| Astrometry | |
| Radial velocity (Rv) | −20.1±4.0 km/s |
| Proper motion (μ) | RA: −644.387 mas/yr Dec.: −360.803 mas/yr |
| Parallax (π) | 34.2281±0.1906 mas |
| Distance | 95.3 ± 0.5 ly (29.2 ± 0.2 pc) |
| Absolute magnitude (MV) | 2.89 |
| Orbit | |
| Period (P) | 1,142.4±1.1 d |
| Semi-major axis (a) | 2.72 AU |
| Eccentricity (e) | 0.110±0.012 |
| Inclination (i) | 141.3+1.0 −2.0° |
| Longitude of the node (Ω) | 163.5±2.8° |
| Periastron epoch (T) | 57,025±22 MJD |
| Argument of periastron (ω) (secondary) | 69.4±7.4° |
| Semi-amplitude (K1) (primary) | 3.847±0.051 km/s |
| Details | |
| 49 Lib Aa | |
| Mass | 1.55+0.07 −0.13 M☉ |
| Radius | 1.86+0.05 −0.04 R☉ |
| Luminosity | 4.74±0.03 L☉ |
| Surface gravity (log g) | 3.93±0.10 cgs |
| Temperature | 6,190±80 K |
| Metallicity [Fe/H] | −0.02 dex |
| Rotational velocity (v sin i) | 9.2±0.4 km/s |
| Age | 12±1 Gyr |
| 49 Lib Ab | |
| Mass | 0.50+0.03 −0.04 M☉ |
| Other designations | |
| 49 Lib, BD−16°4196, FK5 1419, GJ 3931, HD 143333, HIP 78400, HR 5954, SAO 159625, WDS J16003-1632A | |
| Database references | |
| SIMBAD | data |
49 Librae is a binary star system in the Zodiac constellation of Libra. It has an apparent visual magnitude of 5.47, making it faintly visible to the naked eye from dark suburban skies as a dim, yellow-white-hued star. The system is located 95 light-years away from the Sun, based on parallax, but is drifting closer with a radial velocity of −20 km/s.
The Bayer designation Phi Scorpii has been associated with this star. No star is found at the position marked φ Scorpii in Johann Bayer's Uranometria. The closest stars to that position are 48 and 49 Librae; 48 Librae is clearly shown but not given a designation while no star is shown at the position of 49 Librae. In his Uranographia Bode assigned the designation φ Scorpii to the star now known as 49 Librae. The designation is no longer in use.