What are Type Ia supernovae?

A Type Ia supernova is like a giant exploding balloon that lights up the whole neighborhood.

Imagine two friends sharing a balloon, one friend is a white dwarf star, and the other is another star nearby. The white dwarf keeps pulling in gas from its friend until it gets too heavy. At some point, poof! It can no longer hold back, and everything goes boom, like a balloon that bursts after being overfilled with air.

• The white dwarf is like a tiny but very strong sponge.
• It slowly soaks up gas from its neighbor until it becomes too full.
• When it can’t take any more, it explodes in a bright flash of light, this is the supernova.

This explosion is super bright and consistent, making it like a lighthouse for astronomers. They use these explosions to measure how far away galaxies are, just like using a known distance between two things to figure out how big something else is.