VOA慢速英语:科学家发现史上最强大超新星

galaxy - n. any one of the very large groups of stars that make up the universe

theory - n. an idea or set of ideas that is intended to explain facts or events

astrophysicist - n. a scientist who studies the physical and chemical properties and structures of stars, planets and other objects in outer space

gravity - n. the natural force that tends to cause physical things to move towards each other

collision - n. a crash in which two or more things or people hit each other

pulsational - adj. a periodically recurring increase and decrease of a quantity, such as pressure, volume or voltage

astronomy - n. the scientific study of stars, planets, and other objects in outer space