SS Ursae Minoris is a cataclysmic variable star system in the constellation Ursa Minor. It was discovered visually and by its X-ray emissions separately in 1982 before they were understood to be coming from the same object.[5] It is classified as a SU Ursae Majoris variable subclass of dwarf nova in that it has both 'normal' outbursts of increased brightness as well as even brighter 'superoutbursts'. However, unlike other SU Ursae Majoris stars, the superoutbursts are of longer duration than the regular outbursts.[3]
 A visual band light curve for SS Ursae Minoris. The main plot shows a superoutburst, and the inset plot shows superhumps seen on April 8-9, 1998. Adapted from Kato et al. (1998)[1] | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Ursa Minor |
| Right ascension | 15h 51m 22.3401s[2] |
| Declination | +71° 45′ 11.8343″[2] |
| Characteristics | |
| Variable type | dwarf nova[3] |
| Astrometry | |
| Proper motion (μ) | RA: 13.085±0.080[2] mas/yr Dec.: −12.260±0.088[2] mas/yr |
| Parallax (π) | 1.8871 ± 0.0497 mas[2] |
| Distance | 1,730 ± 50 ly (530 ± 10 pc) |
| Details | |
| Other designations | |
| Database references | |
| SIMBAD | data |
The two stars orbit each other every 98 minutes.[3]