Just Some GasesGaseous clouds and dust particles float around in the galaxy. A disturbance, such as a comet or a supernova far, far away, causes movement and pressure change around the gas clouds.
A Big DisturbanceThe disturbance in the clouds causes the gases to draw inwards and form clumps. The clumps start to collapse under their own gravitational pull.
Hot Balls of Fire!The collapsing clumps of gases start rotating and heating up. They flatten into a disc shape while rotating.
Hello, ProtostarThe rotating disc spins faster and faster, pulling in other materials from the galaxy around it. The center of the rotating clump becomes a hot core, called a protostar. Materials around the star that don't stick to the core can become other stars, planets or comets.
Protostar Gets HotterThe protostar continues to heat up and rotate. Helium and energy are produced by fusing hydrogen atoms in the hot temperature.
The Final BlastMillions of years pass, and the hot core blasts away particles and dust around it, forming a star.
The Birth of a Star By Emily Hackeling
All information from: http://science.nasa.gov/astrophysics/focus-areas/how-do-stars-form-and-evolve/