The first stars of the universe were very different than the stars we see today. They were made purely of hydrogen and helium, without heavier elements to help them generate energy in their core. As a result, they were likely hundreds of times more massive than the sun. But some of the first stars may have been even stranger. In the early universe, dark matter could have been more concentrated than it is now, and it may have powered strange stellar objects known as dark stars.
These dark stars would have been gigantic, with a diameter tens of thousands, even hundreds of thousands of times wider than the sun. But they would have been dim and fairly low-density. If they existed, they would have been too faint and distant for current telescopes to detect them. But the Nancy Grace Roman space telescope, formerly called WFIRST, in combination with the JWST, can help us in finding them. If successful, then this might provide insight regarding the formation of supermassive black holes.
