When does a nebula become a star?

1 Answer
Mar 8, 2018

When the giant clouds of gas and dust begin to clump together and nuclear fusion occurs.



When gravity pulls the clouds of gas together, it begins to heat up, a Protostar is formed before Nucleosynthesis and it grows by acquiring mass from its surrounding envelope of interstellar dust and gas. It then becomes a T-Tauri star, which is a pre-main-sequence star in the process of contracting to the main sequence along the Hayashi track. Pre-main-sequence stars are stars that haven't yet become main sequence. Main Sequence Stars fuse hydrogen to form Helium, creating energy in the process.