32 Virginis

32 Virginis, also known as FM Virginis, is a star located about 250 light years from the Earth, in the constellation Virgo.^[2] 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.^[3] 32 Virginis is a binary star,^[11] and the more massive component of the binary is a Delta Scuti variable star which oscillates with a dominant period of 103.51 minutes.^[11]

32 Virginis

A light curve for FM Virginis, plotted from TESS data.[1] The 103.51 minute period is marked in red.
Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Virgo
Right ascension	12h 45m 37.05805s[2]
Declination	+07° 40′ 23.9689″[2]
Apparent magnitude (V)	5.20 - 5.28[3]
Characteristics
Spectral type	F0 IIIm (primary)[4] + A7V (secondary)[5]
U−B color index	+0.15 [6]
B−V color index	+0.33[6]
Variable type	Delta Scuti[3]
Astrometry
Proper motion (μ)	RA: −107.527±0.697[2] mas/yr Dec.: 4.915±0.344[2] mas/yr
Parallax (π)	12.8075±0.3062 mas[2]
Distance	255 ± 6 ly (78 ± 2 pc)
Absolute magnitude (MV)	+1.75[5]
Orbit[7]
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[5] M☉
Surface gravity (log g)	3.75[8] cgs
Temperature	7,450[8] K
Rotational velocity (v sin i)	24[8] km/s
secondary
Mass	1.9[5] M☉
Rotational velocity (v sin i)	140[8] km/s
Other designations
FM Vir, d2 Virginis, HD 110951, BD+08 2639, HIP 62267, HR 4847, SAO 119574,[9] Boss 3323[10]
Database references
SIMBAD	data

In 1914, Walter Sydney Adams announced that 32 Virginis is a spectroscopic binary.^[12] John Beattie Cannon published the first set of orbital elements for the binary system in 1915.^[13] Corrado Bartolini et al. made photometric observations of the star in early 1971, and found that the star showed variability due to pulsations.^[14] In 1974, 32 Virginis was given the variable star designation FM Virginis.^[15] Donald Kurtz et al. determined that the star was a Delta Scuti variable, in 1976.^[8]

The primary star is believed to be an Am star similar to rho Puppis - a pulsating post-main sequence star.^[16]