V Sagittae

V Sagittae
Location of V Sagittae (circled) in Sagitta
Observation data
Epoch J2000      Equinox J2000
Constellation Sagitta
Right ascension 20h 20m 14.691s
Declination +21° 06′ 10.44″
Apparent magnitude (V) 8.6-13.9
Characteristics
Evolutionary stage White dwarf (primary)
Spectral type Be
Variable type eclipsing and cataclysmic
Astrometry
Proper motion (μ) RA: −2.133 mas/yr
Dec.: −6.489 mas/yr
Parallax (π)0.3310±0.0206 mas
Distance9,900 ± 600 ly
(3,000 ± 200 pc)
Absolute magnitude (MV)−2.2
Orbit
Period (P)12.34 hours
Semi-major axis (a)4.36 R
Inclination (i)65–80°
Semi-amplitude (K1)
(primary)
320 km/s
Semi-amplitude (K2)
(secondary)
85 km/s
Details
White dwarf (primary)
Mass1.0 M
Donor (secondary)
Mass0.8–1.0 M
Other designations
AAVSO 1015+20, V Sge, GSC 01643-01764
Database references
SIMBADdata

V Sagittae or V Sge is a cataclysmic variable in the constellation Sagitta. It is the only super soft X-ray source non-magnetic cataclysmic variable found so far. Lidiya Tseraskaya discovered the variability of this star, in 1902. It appeared with its variable star designation in Annie Jump Cannon's 1907 work Second catalogue of variable stars.