Sigma Cassiopeiae

Sigma Cassiopeiae is a binary star system in the northern constellation of Cassiopeia. Its name is a Bayer designation that is Latinized from σ Cassiopeiae, and abbreviated Sigma Cas or σ Cas. The pair have a combined apparent magnitude of +4.88, making it visible to the naked eye. Based on Parallax measurements, it is located at a distance of 1,200 to from Earth.

The primary component, σ Cassiopeiae A, has an apparent magnitude of +5.01 and presents as a subgiant star with a stellar classification of B2 IV. It is a candidate Beta Cephei variable and is rotating rapidly. Its companion, σ Cassiopeiae B, is a main sequence dwarf with a class of B3 V and an apparent magnitude of +7.14. The two stars are three arcseconds apart.

Naming

In Chinese, (), meaning Flying Serpent, refers to an asterism consisting of σ Cassiopeiae, α Lacertae, 4 Lacertae, π² Cygni, π¹ Cygni, HD 206267, ε Cephei, β Lacertae, ρ Cassiopeiae, τ Cassiopeiae, AR Cassiopeiae, 9 Lacertae, 3 Andromedae, 7 Andromedae, 8 Andromedae, λ Andromedae, κ Andromedae, ι Andromedae, and ψ Andromedae. Consequently, the Chinese name for σ Cassiopeiae itself is (, ).

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