fusion
gravity
magnetism
Correct!
Gravity pulls the gas and dust into clumps. If the clump is massive enough, gravity causes the pressure and temperature to rise so high that fusion begins, and a star forms!
Mordecai-Mark Mac Low
In college, Mordecai-Mark Mac Low decided to take science classes that looked like fun. So he chose astrophysics, which uses physics to under- stand how the universe works. Today, he's an astrophysicist, studying how stars, planets, and galaxies form. Since these process take millions of years, he models them using computer simula- tions. Then he compares the models to observa-tions of objects at different stages of formation.