supermassive       
adjective  physics specialized (also super-massive) uk/ˌsuː.pəˈmæs.ɪv/ us/ˌsuː.pɚˈmæs.ɪv/
 (天体)超大质量的
A supermassive star or black hole (= a region in space where gravity is so strong that not even light can escape) that has an extremely large mass (= contains a very large amount of matter).
  Supermassive black holes can be as big as our entire solar system.
 It is very unusual to be able to see the death of super-massive stars. 能够看到超大质量恒星的死亡是非常不寻常的。 
 - More examples
 - A supermassive black hole can have a mass millions of times greater than that of the sun.
 - Supermassive stars like this are extremely rare in the universe.
 - There may be a supermassive black hole at the centre of the galaxy.
 - Quasars are believed to be powered by gas falling into supermassive black holes.