Tau Andromedae, Latinized from τ Andromedae, is the Bayer designation for a single star in the northern constellation of Andromeda. It has an apparent visual magnitude of +4.94, which is bright enough to be viewed from dark suburban skies. From parallax measurements made during the Gaia mission, the distance to this star can be estimated as roughly from Earth. The brightness of this star is diminished by 0.24 in magnitude due to extinction caused by intervening gas and dust. It is drifting closer to the Sun with a radial velocity of −14 km/s.
The spectrum of this star matches a stellar classification of B5 III, with the luminosity class of III indicating that this is a giant star. It is radiating about 851 times the luminosity of the Sun from its photosphere at an effective temperature of 12,670 K. The star is an estimated 217 million years old and is spinning with a high projected rotational velocity of ~74 km/s.
Naming
In Chinese, (), meaning Heaven's Great General, refers to an asterism consisting of τ Andromedae, γ Andromedae, φ Persei, 51 Andromedae, 49 Andromedae, χ Andromedae, υ Andromedae, 56 Andromedae, β Trianguli, γ Trianguli and δ Trianguli. Consequently, the Chinese name for τ Andromedae itself is (, .).
References
External links
Image Tau Andromedae
B-type giants
Andromeda (constellation) Andromedae, Tau BD+39 0378 Andromedae, 53 010205 007818 0477