49 Librae

49 Librae
Observation data
Epoch J2000      Equinox J2000
Constellation Libra
Right ascension 16h 00m 19.61087s[1]
Declination –16° 32′ 00.5483″[1]
Apparent magnitude (V) 5.47[2]
Characteristics
Evolutionary stage main sequence
Spectral type F8 V[3]
U−B color index +0.03[2]
B−V color index +0.52[2]
Astrometry
Radial velocity (Rv)−20.1±4.0[4] km/s
Proper motion (μ) RA: –644.387[1] mas/yr
Dec.: –360.803[1] mas/yr
Parallax (π)34.2281 ± 0.1906 mas[1]
Distance95.3 ± 0.5 ly
(29.2 ± 0.2 pc)
Absolute magnitude (MV)2.89[4]
Orbit[3]
Period (P)1,142.4±1.1 d
Semi-major axis (a)≥ 59.53±0.244 Gm
Eccentricity (e)0.110±0.012
Inclination (i)143.0±2.0°
Longitude of the node (Ω)163.5±2.8°
Periastron epoch (T)57025±22 MJD
Argument of periastron (ω)
(secondary)		69.4±7.4°
Semi-amplitude (K1)
(primary)		3.847±0.051 km/s
Details
49 Lib A
Mass1.4[3] M☉
Radius1.86+0.05
−0.04[1] R☉
Luminosity4.74±0.03[1] L☉
Surface gravity (log g)4.14[5] cgs
Temperature6,237[4] K
Metallicity [Fe/H]–0.02[4] dex
Rotational velocity (v sin i)9.6±1.0[3] km/s
Age12[6] Gyr
49 Lib B
Mass0.45[3] M☉
Other designations
49 Lib, BD–16°4196, FK5 1419, GJ 3931, HD 143333, HIP 78400, HR 5954, SAO 159625, WDS J16003-1632A[7]
Database references
SIMBADdata

49 Librae is the Flamsteed designation for a binary star[8] system in the Zodiac constellation of Libra. It has an apparent visual magnitude of 5.47,[2] 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,[1] but is drifting closer with a radial velocity of −20 km/s.[4]

The variable nature of the velocity for 49 Librae was first noted by W. S. Adams in 1924. It is a single-lined spectroscopic binary with an orbital period of 3.128 years and an eccentricity of 0.11.[3] The primary component has a stellar classification of F8 V or F9 V,[3] indicating it is an F-type main-sequence star. It has an estimated 1.4 times the mass of the Sun, while the companion only has 0.4 solar masses.[3] The system is a source for radio and X-ray emissions, which may be coming from the secondary companion.[9]

  1. ^ a b c d e f g h Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference aaass34_1 was invoked but never defined (see the help page).
  3. ^ a b c d e f g h Cite error: The named reference Willmarth2016 was invoked but never defined (see the help page).
  4. ^ a b c d e Cite error: The named reference aaa475_2_519 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference apj1_354_310 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Fuhrmann2017 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference apjs180_1_117 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Lazio2010 was invoked but never defined (see the help page).