The Massachusetts Institute of Technology (MIT) team has found three of the universe’s oldest stars. They were shocked to learn that the stars weren’t in some distant galaxy visible only to the incredibly potent James Webb Space Telescope. The study, which was published on May 14 in the journal Monthly Notices of the Royal Astronomical Society, states that they are inside the “halo” of the Milky Way, in our own galactic neighborhood.
Because they think that each star once belonged to a small, primordial galaxy that was eventually absorbed by the larger but still expanding Milky Way, the astronomers have named the stars “SASS,” or Small Accreted Stellar System stars. All that remains of each galaxy are the three stars as of right now. They travel around the periphery of the Milky Way, where the group believes further ancient stellar survivors might exist.
According to MIT physics professor Anna Frebel, “these oldest stars should definitely be there, given what we know of galaxy formation.” They are kin to us in the cosmos. And we now know where to look for them.”
The idea for this study originated in a class that Frebel introduced in the Fall 2022 semester under the name Observational Stellar Archaeology. Students applied the methods they had acquired in class to stars that had not yet been investigated to ascertain their origins, after learning how to examine old stars. Several of the recent grads and undergraduates who participated in it are now co-authors of this new research.