Galaxies that stop forming stars are called quiescent galaxies. Another galaxy typically triggers this process by siphoning off the gas necessary for star formation. However, in the case of PEARLSDG, this is not the situation. According to the study’s author, Tim Carleton of Arizona State University, PEARLSDG is remarkable for another reason: the James Webb Space Telescope can detect individual red giant branch (RGB) stars in the dwarf galaxy because these stars are bright at the observed wavelengths.

Discoveries like this prompt astronomers to reconsider the validity of galaxy evolution models. It is likely that there are more isolated dwarf galaxies in which the star formation process has also ceased.