69868
The date of the Cassiopeia A supernova event was determined from light echoes off nebulae , while the age of supernova remnant RX J0852 .
 astronomical object: Cassiopeia A
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: Cassiopeia A 
Answer:
 astronomical object: Cassiopeia A