Psi Virginis
Psi Virginis (ψ Vir, ψ Virginis) is a suspected binary star system in the zodiac constellation of Virgo. It can be seen with the naked eye and has an apparent visual magnitude of about 4.8. Based upon the annual parallax shift of 5.99 milliarcseconds, the distance to this star is roughly 540 light years. The angular size of Psi Virginis was measured on December 26, 1975 during an occultation by the Moon, yielding the estimate 6.5±0.3 mas.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Virgo |
| Right ascension | 12h 54m 21.16342s |
| Declination | −09° 32′ 20.3783″ |
| Apparent magnitude (V) | 4.73 - 4.96 |
| Characteristics | |
| Spectral type | M3 IIICa-1 |
| U−B color index | +1.57 |
| B−V color index | +1.58 |
| Variable type | LB |
| Astrometry | |
| Radial velocity (Rv) | +12.82 km/s |
| Proper motion (μ) | RA: −18.08 mas/yr Dec.: −19.52 mas/yr |
| Parallax (π) | 5.99 ± 0.23 mas |
| Distance | 540 ± 20 ly (167 ± 6 pc) |
| Absolute magnitude (MV) | −1.34 |
| Details | |
| Mass | 3.95 M☉ |
| Radius | 93 R☉ |
| Luminosity | 3,548 L☉ |
| Surface gravity (log g) | 1.05 cgs |
| Temperature | 3,500 K |
| Metallicity [Fe/H] | −0.10 dex |
| Other designations | |
| Database references | |
| SIMBAD | data |
The primary component is an evolved red giant star with a stellar classification of M3 IIICa-1. It is an irregular variable with seven measured pulsation periods ranging from 22.4 to 162.6 days, and amplitudes ranging up to 0.m022. The star is a bright X-ray source with a luminosity of 21.58×1029 ergs s−1. There is a magnitude 8.3 companion at an angular separation of 0.04 arcseconds.