What Was It Like When the First Stars Began to Shine?

The Formation of the First Stars

After the Big Bang, it took less than a second for protons and neutrons to form, minutes for atomic nuclei, and hundreds of thousands of years for neutral atoms to form. However, the formation of stars took much longer, ranging from tens of millions to a hundred million years.

The first stars in the Universe were exclusively made of hydrogen and helium, making them more massive and shorter-lived compared to today's stars.

Gravitational forces, the slow process of gravitation on cosmic scales, and the slow propagation of gravity all contributed to the lengthy formation time of the first stars.

Transformation of the Universe

As the first stars began to shine, they brought about significant transformations in the Universe.

Gravitational forces caused matter to clump together, eventually leading to the collapse of dense gas clouds and the formation of stars.

The clumpy structure of the Universe grew over time, with dense regions becoming richer in matter and less dense regions becoming poorer.

The formation of the first stars was accompanied by the ionization of neutral atoms, reionization, and the emission of ultraviolet light.

Characteristics of the First Stars

Due to the absence of heavy elements, the first stars could not cool as efficiently as modern stars.

This resulted in the formation of only the largest, most massive clumps of gas becoming stars.

The first stars were on average about 10 times more massive than the Sun, with some reaching several thousand solar masses.

Their radiation, dominated by ultraviolet light, ionized the surrounding neutral atoms and influenced the formation of giant planets.