60233
Several globular clusters ( like M " 15 ) have extremely massive cores which may harbor black holes , although simulations suggest that a less massive black hole or central concentration of neutron stars or massive white dwarfs explain observations equally well .
 astronomical object: M " 15
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
 Entities: M " 15 
Answer:
 astronomical object: M " 15