XX Virginis
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Virgo |
| Right ascension | 14h 16m 48.593s |
| Declination | −06° 17′ 15.06″ |
| Apparent magnitude (V) | 11.55 to 12.78 |
| Characteristics | |
| Spectral type | kA7hF6 |
| Variable type | Anomalous Cepheid |
| Astrometry | |
| Radial velocity (Rv) | −55.0 km/s |
| Proper motion (μ) | RA: −11.421 mas/yr Dec.: −10.826 mas/yr |
| Parallax (π) | 0.144±0.0194 mas |
| Distance | 9,360 ± 1,100 ly (2,869±337 pc) |
| Absolute magnitude (MV) | −0.74 |
| Details | |
| Mass | 0.6 M☉ |
| Radius | 13±7 R☉ |
| Luminosity | 156 L☉ |
| Surface gravity (log g) | 1.95 (avg) cgs |
| Temperature | 6,410 K (6,030 to 7,610) K |
| Metallicity [Fe/H] | −1.57 dex |
| Age | 293 Myr |
| Other designations | |
| XX Vir, TIC 6030027, GCRV 8351 | |
| Database references | |
| SIMBAD | data |
XX Virginis is a variable star in the equatorial constellation of Virgo, abbreviated XX Vir. It ranges in apparent visual magnitude from 11.55 to 12.78, which is much too faint to be visible to the naked eye. The star is located at an estimated distance of roughly 9,400 light-years (2,900 pc).
This is classified as a type II Cepheid of the BL Her type, having a short pulsation period of 1.348 days. However, a 2014 survey has it classified as an anomalous Cepheid of the BL Boo type. The light curve is asymmetrical, resembling that of a type ab RR Lyrae variable. On the HR diagram it is positioned above the horizontal branch. For this reason, it is sometimes used as the prototype of, "Above Horizontal Branch variables of subtype 1."
This is a very metal-poor star with an estimated 0.6 times the mass of the Sun. The effective temperature and radius vary depending on the phase of the pulsation cycle.