Caption

This artist’s concept shows a massive, blue star being torn apart by a black hole. Gas from the star is pulled into the black hole’s accretion disk. Gravitational lensing by the black hole bends light from the far side of the disk, making it appear to wrap around and over the black hole.

Population III stars, the earliest stars that formed, are stars composed mostly of hydrogen and helium. They are believed to have been much larger, hotter, and more massive than our Sun. Using NASA’s upcoming Roman Space Telescope, and bright, energetic phenomena known as tidal disruption events, astronomers theorize that we will be able to locate dozens of these stars. 

Tidal disruption events occur when stars move too close to black holes, and are disturbed by their gravity. With each orbit, more and more of the star’s material is taken by the black hole, where complex physical processes cause it to glow brightly enough to be seen from billions of light-years away. The Roman Space Telescope, with its ability to provide a panoramic field of view 200 times larger than the infrared view of the sky from NASA’s Hubble Space Telescope and to survey the sky 1,000 times faster, is a key element in detecting dozens of TDEs, a meaningful sample size. 

Since these Population III stars were the first nuclear furnaces, where the first elements heavier than helium (which astronomers call metals) were generated, understanding them is key to putting together how the complex systems of galaxies that we see today formed. This strategy may not only help us peer into what occurred in the early universe, but also the processes in galaxies closer to home.