Upsilon Tauri

Upsilon Tauri (υ Tau, υ Tauri) is a triple star system in the constellation Taurus and a member of the Hyades star cluster. It is approximately 155 light years from Earth.

The primary component, Upsilon Tauri A, is a white A-type main sequence dwarf with a mean apparent magnitude of +4.28. It is classified as a Delta Scuti type variable star and its brightness varies from magnitude +4.28 to +4.31 with a period of 3.56 hours. It is also a spectroscopic binary, and is composed of two stars with apparent magnitudes of +4.4 and +6.5 which are separated by 0.02 arcseconds, or at least 1 Astronomical Unit. A third star, 12th magnitude in brightness, orbits the pair with a separation of 110 arcseconds.

Occasionally this star system shares the Bayer designation υ Tauri with 72 Tauri, which is separated from it by 0.29° in the sky. 72 Tauri is not a member of the Hyades cluster, being three times farther away from Earth.