The Sun ignites
The collapsing core of the nebula gets hot enough to fuse hydrogen, and starts a fire still burning today.
- When
- Known to
- ± 2 million years
- Era
- Hadean
The centre of the collapsing cloud reaches roughly 15 million kelvin and hydrogen fusion begins, halting the collapse and turning a contracting protostar into a stable main-sequence star. The Sun holds 99.86% of the Solar System's mass; everything else is built from the leftovers of the disk around it. It has since converted about half its core hydrogen and will continue for roughly another five billion years.