Magnitude 4.78 Apparent magnitude (V) 4.78 | Constellation Eridanus | |
Similar Delta Eridani, Theta Eridani, Gamma Eridani, Zeta Eridani | ||
Tau2 Eridani (τ2 Eri, 2 Eridani) is a star in the constellation Eridanus. It is one of a series of stars that share the Bayer designation Tau Eridani. The traditional name for this star is Angetenar, meaning "bend of the river" in Arabic. It is visible to the naked eye with an apparent visual magnitude of 4.78. The distance to τ2 Eri, as determined via the parallax method, is around 187 light years.
In Chinese, 天苑 (Tiān Yuàn), meaning Celestial Meadows, refers to an asterism consisting of τ2 Eridani, γ Eridani, π Eridani, δ Eridani, ε Eridani, ζ Eridani, η Eridani, π Ceti, τ1 Eridani, τ3 Eridani, τ4 Eridani, τ5 Eridani, τ6 Eridani, τ7 Eridani, τ8 Eridani and τ9 Eridani. Consequently, τ2 Eridani itself is known as 天苑九 (Tiān Yuàn jiǔ, English: the Ninth Star of Celestial Meadows.)
Tau2 Eridani is an evolved K-type giant star with a stellar classification of K0 III. It is a red clump giant on the horizontal branch of the Hertzsprung–Russell diagram, indicating that is it now generating energy through the thermonuclear fusion of helium at its core. It is a member of the Galactic thin disk population.
Around 660 million years old, Tau2 Eridani has 2.4 times the mass of the Sun and has expanded to over 8 times the solar radius. It shines with nearly 43 times the Sun's luminosity from an outer atmosphere that has an effective temperature of 5,049 K.