Magnitude 9.2 Apparent magnitude (V) 9.2 | ||
Similar U Orionis, Sigma Orionis, Mu Orionis, FU Orionis, Chi1 Orionis | ||
S Orionis is a red giant star in the constellation Orion.
Contents
Variability
S Orionis is a Mira variable that pulsates with a 420‑day cycle, and varies in radius from 2.0 to 2.3 astronomical units.
Companion
S Orionis is listed in the Washington Double Star Catalog as a double star with a tenth magnitude companion 47" away. The companion is G0 star HD 294176.
Circumstellar environment
S Orionis is surrounded by masers and dust condensed from its cool stellar wind. The size of the dust shells varies as the star pulsates and changes temperature, from around 8 AU to 10 AU across. The positions of the masers have been measured very accurately using VLBI.
References
S Orionis Wikipedia(Text) CC BY-SA