HN Librae
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Libra |
| Right ascension | 14h 34m 16.81166s |
| Declination | −12° 31′ 10.4145″ |
| Apparent magnitude (V) | 11.32 |
| Characteristics | |
| Spectral type | M4.0V |
| B−V color index | 1.633±0.052 |
| Variable type | BY Dra |
| Astrometry | |
| Radial velocity (Rv) | −1.36±0.20 km/s |
| Proper motion (μ) | RA: −355.138 mas/yr Dec.: 593.040 mas/yr |
| Parallax (π) | 159.9225±0.0546 mas |
| Distance | 20.395 ± 0.007 ly (6.253 ± 0.002 pc) |
| Absolute magnitude (MV) | 12.41 |
| Details | |
| Mass | 0.291±0.013 M☉ |
| Radius | 0.299±0.009 R☉ |
| Luminosity (bolometric) | 0.010106±0.000069 L☉ |
| Surface gravity (log g) | 4.76±0.13 cgs |
| Temperature | 3347±50 K |
| Metallicity [Fe/H] | −0.18±0.15 dex |
| Rotation | 96±2 d |
| Rotational velocity (v sin i) | <2.0 km/s |
| Age | 0.8–8.0 Gyr |
| Other designations | |
| HN Lib, BD−11 3759, GJ 555, HIP 71253, Ci 20 870, LFT 1120, LHS 2945, LPM 532, LTT 5759, NLTT 37751, PLX 3296, PM 14316-1219, Wolf 1481, TYC 5572-804-1, GSC 05572-00804, 2MASS J14341683-1231106 | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
Location of HN Librae in the constellation Libra | |
HN Librae, also known as Gliese 555, is a red dwarf with one or more orbiting exoplanets in the constellation Libra. With an apparent visual magnitude of 11.32, it can only be viewed through a telescope. The system is located at a distance of 20.4 light years based on parallax measurements, but is drifting closer to the Sun with a radial velocity of −1.4 km/s. It does not appear to belong to any known stellar moving group or association.
This is an M-type main-sequence star, a red dwarf, with a stellar classification of M4.0V. The chromosphere of this star is weakly active, causing starspots that vary the stellar luminosity as it rotates. It has 29% of the mass of the Sun and 30% of the Sun's girth. On average, the star is radiating just 1% of the luminosity of the Sun from its photosphere at an effective temperature of 3,347 K. The star is spinning slowly with a rotation period of around 96 days.