What if some of the antimatter that was thought to have disappeared was hiding in the form of anti-stars? Researchers from the Institute for Research in Astrophysics and Planetology (IRAP—CNRS/CNES/UT3 Paul Sabatier) are using the Fermi gamma-ray space telescope to put the most constraining limits ever on this hypothesis. The results of their work were published on April 20, 2021 in Physical Review D.