A B class giant (center) in the Vandor system.
A B class star was a classification for a red giant star.
The Vandor system, a binary star system, had a B class giant as its primary star, and a pulsar as the companion star. (TNG: "We'll Always Have Paris")
This designation presumably does not refer to the spectral type known as "B-type", which describes a class of blue stars rather than a sub-type of red giants.