Xi Aquilae
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Aquila |
| Right ascension | 19h 54m 14.8815s |
| Declination | +08° 27′ 41.235″ |
| Apparent magnitude (V) | 4.722 |
| Characteristics | |
| Evolutionary stage | red clump |
| Spectral type | G9.5 IIIb |
| U−B color index | +0.89 |
| B−V color index | +1.049 |
| R−I color index | 0.57 |
| Astrometry | |
| Radial velocity (Rv) | −42.10 ± 0.14 km/s |
| Proper motion (μ) | RA: 101.694(107) mas/yr Dec.: −81.141(77) mas/yr |
| Parallax (π) | 17.5183±0.1006 mas |
| Distance | 186 ± 1 ly (57.1 ± 0.3 pc) |
| Absolute magnitude (MV) | +0.96 |
| Details | |
| Mass | 1.74+0.21 −0.28 M☉ |
| Radius | 10.17±0.16 R☉ |
| Luminosity | 58.54+6.02 −12.37 L☉ |
| Surface gravity (log g) | 2.61±0.08 cgs |
| Temperature | 4,841 K |
| Metallicity [Fe/H] | −0.11+0.06 −0.1 dex |
| Rotational velocity (v sin i) | 5.2 km/s |
| Age | 980±180 Myr |
| Other designations | |
| Libertas, ξ Aquilae, Xi Aql, ξ Aql, 59 Aquilae, BD+08 4261, GC 27558, HD 188310, HIP 97938, HR 7595, SAO 125210, PPM 168913, WDS J19542+0828AB | |
| Database references | |
| SIMBAD | data |
Xi Aquilae is a star in the equatorial constellation of Aquila. Its name is a Bayer designation that is Latinized from ξ Aquilae, and abbreviated Xi Aql or ξ Aql. The star has the official name Libertas, pronounced /ˈlɪbərtæs/, a Latin word for liberty. Based on parallax measurements, it is located at a distance of 186 light-years (57 parsecs) from the Sun. This is an aging giant star that is close to a billion years old.
A companion star has been detected using speckle interferometry 0.09″ away.
As of 2008, an extrasolar planet has been confirmed in orbit around the star. Designated Xi Aquilae b, this massive world was later named Fortitudo.