58000
The similarities between the two events , in terms of gamma ray , optical and x-ray emissions , as well as to the nature of the associated host galaxies , are " striking " , suggesting the two separate events may both be the result of the merger of neutron stars , and both may be a kilonova , which may be more common in the universe than previously understood , according to the researchers .
 astronomical object: galaxies; astronomical object: kilonova
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: galaxies, kilonova 
Answer:
 astronomical object: galaxies; astronomical object: kilonova