52960
One of the consequences of general relativity is massive objects ( such as a cluster of galaxies ) lying between a more distant source ( such as a quasar ) and an observer should act as a lens to bend the light from this source .
 quasar
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
Answer:
 quasar