Which statement describes a Supernova?

• A. A star that explodes and becomes extremely luminous
• B. A planet that orbits a star
• C. A cluster of galaxies
• D. A comet entering the inner solar system

Answer: (A)

A supernova is a star’s explosive end that releases an immense amount of energy and becomes extremely luminous for a short time. This dramatic brightening happens when a massive star runs out of fuel and its core collapses, or when a white dwarf in a binary system accretes enough material to trigger a runaway fusion reaction, blowing the star apart. The resulting explosion can outshine an entire galaxy briefly and spreads heavy elements into space. The other descriptions don’t fit because they refer to a planet orbiting a star, a cluster of galaxies, or a comet approaching the inner solar system, none of which involve a star undergoing a colossal explosion and brief, intense light.