4. 159 feet: 180-(264-180)/4
5. b: lines are closer together
6. c as already explained
Answer:
star
Explanation:
For a brief time, a supernova can shine as brightly as an entire galaxy, but will fade again over a matter of days. The explosion occurs when a high-mass star finally runs out of nuclear fuel. ... The resulting shock wave creates an expanding shell of gas and dust called a supernova remnant.
