| In the core of what is now a protostar, hydrogen is burning, and heavier elements, the first of which is helium, are produced. |
| It became known as the Becklin-Neugebauer object and was later determined to be the first protostar to be directly observed. |
| The ejected material is channeled into narrow jets perpendicular to the disk, while material from the disk falls onto the protostar. |
| Rotation forces some of the matter to accumulate in a disk rotating around the protostar. |
| When the interior temperature of a protostar reaches a few million Kelvin it can begin to burn hydrogen and become a main-sequence star. |
| Elongated chains of dust grains like these appear in the early stages of planet formation around a young protostar, according to a microgravity experiment inside a rocket. |
