66 Tauri

66 Tauri, also known as r Tauri, is a binary star in the constellation of Taurus. The combined apparent magnitude of the system is 5.098, with the magnitudes of the two components being 5.8 and 5.9, respectively. Parallax measurements by Hipparcos put 66 Tauri at some 400 light-years (121 parsecs) away.

This is a visual binary where the positions of the two stars are tracked over time, and used to calculate an orbit. The two stars orbit each other every 55 years. Their orbit is fairly eccentric, at 0.720, and the two stars are separated by $-8.7$ on average. Both stars are A-type main-sequence stars with similar masses.