sisters: Pleiades star cluster, photographed by Voyager 2, 16th September 1989, with names of the brightest stars.
The 9 brightest stars in the cluster are named after the 7 Sisters of Greek mythology - Alcyone, Celaeno, Electra, Maia, Merope, Sterope, & Taygeta - and their parents, Atlas and Pleione.
The name Sterope (sometimes Asterope) is applied to both of the pair of stars. My approach would be to call one Sterope and the other Asterope, but nobody listens to me.
Alcyone is the name of only the large, bright star, and apparently not its smaller companion seen here. (Alcyone actually is a multiple star system, but that composition is not visible here.)
This observation was made near the end of Voyager 2’s observations of Neptune. Image dropout errors smoothed. [C1205048].
Image credit: NASA/JPL.