V471 Tauri

V471 Tauri is an eclipsing variable star in the constellation of Taurus. The star has a visual magnitude of 9 which makes it impossible to see with the naked eye. It is around 155 light-years away from the Solar System, in the Hyades star cluster.
In 1970, Burt Nelson and Arthur Young announced that the star is a variable star. It was given its variable star designation in 1972.

Physical properties

The V471 Tauri system has at least two members: a white dwarf star of spectral type D2; and a K-type main sequence star, together a post-common envelope binary. There are variations in the timing of the eclipses that were once thought to be due to a third member of the system, proposed to be a brown dwarf, but a direct imaging search for this object with SPHERE resulted in a non-detection. The eclipse variations may be caused by the Applegate mechanism, or the third body may be a pair of smaller brown dwarfs, which would be too faint to have been detected. Later studies have found that the timing variations cannot be explained solely by additional components of the system; even if one or more brown dwarfs are present, the Applegate mechanism must also be a factor.