The cluster contains a large number of rare , evolved , high-mass stars , including : 6 yellow hypergiants , 4 red supergiants , 24 Wolf-Rayet stars , a luminous blue variable , many OB supergiants , and an unusual supergiant sgB ( e ) star which has been proposed to be the remnant of a recent stellar merger .
The cluster contains a large number of rare , evolved , high-mass stars , including : 6 yellow hypergiants , 4 red supergiants , 24 Wolf-Rayet stars , a luminous blue variable , many OB supergiants , and an unusual supergiant sgB ( e ) star which may be the remnant of a recent stellar merger .