The stars were picked for the resemblance of their arrangement to the Hyades group which form the "head" of Taurus. Before the definition of Taurus Poniatovii, some of these had been part of the obsolete constellation River Tigris.
The brightest of these stars is 72 Oph (3.7 magnitude) in the "horn" of Taurus Poniatovii. The "face" of Taurus Poniatovii is formed by 67 Oph (4.0), 68 Oph (4.4) and 70 Oph (4.0).[1]
The five brightest stars belong to loose open clusterCollinder 359 or Melotte 186. Barnard's Star is also inside the boundaries of this former constellation. Some minor stars (5th and 6th magnitude) now in Aquila formed the "rear" of Taurus Poniatovii.