37 Librae
Star in the constellation Libra
From Wikipedia, the free encyclopedia
37 Librae is a single[8] star in the southern zodiac constellation of Libra. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.61.[2] The star is located 94 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +49 km/s.[5]
 | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Libra |
| Right ascension | 15h 34m 10.70209s[1] |
| Declination | −10° 03′ 52.3063″[1] |
| Apparent magnitude (V) | 4.61[2] |
| Characteristics | |
| Evolutionary stage | subgiant[3] |
| Spectral type | K1III–IV[4] |
| B−V color index | 1.00±0.03[2] |
| Astrometry | |
| Radial velocity (Rv) | +49.25±0.08[5] km/s |
| Proper motion (μ) | RA: +307.63[1] mas/yr Dec.: −234.51[1] mas/yr |
| Parallax (π) | 34.57±0.22 mas[1] |
| Distance | 94.3 ± 0.6 ly (28.9 ± 0.2 pc) |
| Absolute magnitude (MV) | 2.30[2] |
| Details[5] | |
| Mass | 1.38±0.10 M☉ |
| Radius | 5.133±0.043[6] R☉ |
| Luminosity | 12.71±0.69[6] L☉ |
| Surface gravity (log g) | 3.19±0.06 cgs |
| Temperature | 4,809±62[6] K |
| Metallicity [Fe/H] | 0.02±0.04 dex |
| Rotational velocity (v sin i) | 2.02±0.33 km/s |
| Age | 3.39±0.80 Gyr |
| Other designations | |
| 37 Lib, BD−09°4171, FK5 1409, GC 20914, HD 138716, HIP 76219, HR 5777, SAO 140609[7] | |
| Database references | |
| SIMBAD | data |
This is an evolving subgiant star[3] with a stellar classification of K1 III–IV,[4] where the luminosity class indicates the spectrum displays blended traits of a subgiant and a giant star. It is an estimated 3.4 billion years old with 1.4 times the mass of the Sun.[5] Having the supply of hydrogen at its core all but exhausted, the star is starting to expand; currently it has five times the girth of the Sun. It is radiating 12.7 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,809 K.[6] At this temperature, 37 Librae glows with the hue of a K-type star.[9]