[15] Its nature continued to be unclear during the deep visual minimum in 1946, although it was presumed to be related to the detection of an expanding shell around the star.

It is close to the Eddington luminosity limit and normally loses mass at around 10−6 M☉/yr, hundreds of millions of times the rate of the solar wind.

[11][18] The luminosity remains roughly constant during the outbursts at half a million L☉, but the radiation output shifts towards the infra red.

[24] Surface abundances of most heavy elements on Rho Cas are enhanced relative to the Sun, but carbon and oxygen are depleted.

In addition to the expected helium and nitrogen convected to the surface, sodium is strongly enhanced, indicating that the star had experienced a dredge-up while in a red supergiant stage.

[10] The relatively low mass and high luminosity of a post-red supergiant star is a source of instability, pushing it close to the Eddington Limit.

In hypergiants, these pulsations are generally irregular and small, but combined with the overall instability of the outer layers of the star they can result in larger outbursts.

[10] ρ Cassiopeiae is a member of the Chinese constellation Flying Serpent 螣蛇 (Téng Shé), in the Encampment mansion.

Consequently, the Chinese name for ρ Cassiopeiae is 螣蛇十二 (Téng Shé shíèr, English: the Twelfth Star of Flying Serpent)[25]