32 Virginis
32 Virginis, also known as FM Virginis, is a star located about 250 light years from the Earth, in the constellation Virgo. Its apparent magnitude ranges from 5.20 to 5.28, making it faintly visible to the naked eye of an observer well away from city lights. 32 Virginis is a binary star, and the more massive component of the binary is a Delta Scuti variable star which oscillates with a dominant period of 103.51 minutes.
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Virgo |
| Right ascension | 12h 45m 37.05805s |
| Declination | +07° 40′ 23.9689″ |
| Apparent magnitude (V) | 5.20 - 5.28 |
| Characteristics | |
| Spectral type | F0 IIIm (primary) + A7V (secondary) |
| U−B color index | +0.15 |
| B−V color index | +0.33 |
| Variable type | Delta Scuti |
| Astrometry | |
| Proper motion (μ) | RA: −107.527±0.697 mas/yr Dec.: 4.915±0.344 mas/yr |
| Parallax (π) | 12.8075 ± 0.3062 mas |
| Distance | 255 ± 6 ly (78 ± 2 pc) |
| Absolute magnitude (MV) | +1.75 |
| Orbit | |
| Period (P) | 38.324 d |
| Eccentricity (e) | 0.074±0.006 |
| Periastron epoch (T) | 2434039.463±0.038 |
| Argument of periastron (ω) (primary) | 210.02±5.1° |
| Semi-amplitude (K1) (primary) | 48.05±0.33 km/s |
| Details | |
| primary (Delta Scuti variable) | |
| Mass | 2.05 M☉ |
| Surface gravity (log g) | 3.75 cgs |
| Temperature | 7,450 K |
| Rotational velocity (v sin i) | 24 km/s |
| secondary | |
| Mass | 1.9 M☉ |
| Rotational velocity (v sin i) | 140 km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
In 1914, Walter Sydney Adams announced that 32 Virginis is a spectroscopic binary. John Beattie Cannon published the first set of orbital elements for the binary system in 1915. Corrado Bartolini et al. made photometric observations of the star in early 1971, and found that the star showed variability due to pulsations. In 1974, 32 Virginis was given the variable star designation FM Virginis. Donald Kurtz et al. determined that the star was a Delta Scuti variable, in 1976.
The primary star is believed to be an Am star similar to rho Puppis - a pulsating post-main sequence star.