The first stars could have weighed more than 100,000 suns

The universe was just different when I was younger. Recently, astronomers have discovered that complex physics in the young cosmos may have led to the development of supermassive stars, each weighing up to 100,000 times the mass of the Sun.

We currently have no observations of the formation of the first stars in the universe, which is believed to have taken place when our cosmos was only a few hundred million years old. To understand this important epoch, astronomers turn to sophisticated computer simulations to test models of how the first stars formed.

Over the years, astronomers have wrestled with the key question of what the typical size of the first stars is. Some early estimates predicted that the first stars could be hundreds of times more massive than the Sun, while later simulation suggested they would be more normal in size.

A team of researchers recently ran a new round of simulations and came to a very surprising conclusion. Their simulations specifically looked at a phenomenon known as cold buildup. To build large stars, you have to extract a large amount of material in a very small volume very quickly. And you have to do it without raising the temperature of the material, because a hotter material will prevent it from collapsing. So you need some method of removing heat from the material, as it collapses very quickly.

Previous simulations had found the appearance of dense pockets within the first galaxies that cooled rapidly when emitting radiation, but did not have the necessary resolution to follow their subsequent evolution. The new research goes a step further by examining how the cold, dense pockets that initially form in the early universe behave.

These simulations revealed that large flows of cold, dense matter can collide with an accretion disk at the center of gigantic clumps of matter. When that happens, a shock wave is formed. That shock wave quickly destabilizes the gas and causes the instantaneous collapse of large pockets of matter.

Those big bags can be tens of thousands of times more massive than the Sun, and in some cases even 100,000 times more massive than the Sun. With nothing to stop them from collapsing, they immediately form giant stars, known as supermassive stars.

With information from