Tau Cassiopeiae


Tau Cassiopeiae is a solitary, orange hued star in the northern constellation of Cassiopeia. Its name is a Bayer designation that is Latinized from τ Cassiopeiae, and abbreviated Tau Cas or τ Cas. This star is bright enough to be seen with the naked eye, having an apparent visual magnitude of +4.86. Based upon an annual parallax shift of as seen from Earth, this star is located about from the Sun. It is drifting closer with a radial velocity of −20 km/s.
The spectrum of this star indicates it is an evolved, K-type giant star with a stellar classification of K1 IIIa. It is a suspected variable star of unknown type. Tau Cassiopeiae is 3.9 billion years old with about 1.44 times the mass of the Sun and 10 times the Sun's radius. It is radiating 40 times the Sun's luminosity from its expanded photosphere at an effective temperature of around 4,617 K.

Naming

In Chinese, 螣蛇, meaning Flying Serpent, refers to an asterism consisting of τ Cassiopeiae, α Lacertae, 4 Lacertae, π2 Cygni, π1 Cygni, HD 206267, ε Cephei, β Lacertae, σ Cassiopeiae, ρ 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 τ Cassiopeiae itself is 螣蛇十三.