S Ursae Minoris

S Ursae Minoris

The visual band light curve of S Ursae Minoris, from AAVSO data
Observation data
Epoch J2000      Equinox J2000
Constellation Ursa Minor
Right ascension 15h 29m 34.5775s
Declination +78° 38′ 00.2742″
Apparent magnitude (V) 7.5-<13.2
Characteristics
Evolutionary stage AGB
Spectral type M6e-M9e
Variable type Mira
Astrometry
Proper motion (μ) RA: −30.986±0.303 mas/yr
Dec.: 7.006±0.309 mas/yr
Parallax (π)2.5455±0.1578 mas
Distance1,280 ± 80 ly
(390 ± 20 pc)
Details
Mass2.3 M
Radius744 R
Luminosity3,896 L
Surface gravity (log g)1.63 cgs
Temperature3,457 K
Other designations
S UMi, HD 139492, HIP 75847
Database references
SIMBADdata

S Ursae Minoris (S UMi) is a Mira variable star in the constellation Ursa Minor, ranging from magnitude 7.5 to fainter than 13.2 over a period of 331 days.

Williamina Fleming discovered that the star's brightness varies, in 1895.