Protogalaxies 100 million years

According to cosmological models, early galaxies (called protogalaxies) appeared between 100 million and 250 million years after the creation and were the homes of the first stars.

To begin with the dark matter was scattered fairly uniformly throughout the Universe.

Reconstruction of Universe 100 my after creation. Click for image credit.

This picture is a computer-generated simulation of the early clumping together of dark matter about 100 million years after the creation. The box is 140 million light-years across. The red shift letter z is explained here.

Protogalaxies and early stars are thought to have formed at the points where the dark matter was densest. I will discuss star birth and the description of how stars work later in this story.