5687
As O - and B-type stars are so energetic , they only live for a relatively short time .
 astronomical object: O - and B-type stars
Please list all entity words in the text that fit the category.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} 
Answer:
 astronomical object: O - and B-type stars