First globular cluster stellar stream beyond Milky Way

An international team led by Julie Kiel Holm of the Niels Bohr Institute and Hannah Pearson of Technical University of Denmark has discovered the first globular cluster stellar stream beyond the Milky Way, in the ultra-diffuse galaxy UGC9050-Dw1. The finding, published in Nature, demonstrates that these faint stellar structures can be used to measure dark matter in external galaxies, opening new avenues for studying dark matter distribution across different galaxy types. The researchers used the stream to estimate the galaxy's mass and dark matter content, finding results consistent with previous studies. The discovery was made possible by advances in large astronomical datasets and analysis techniques, and future telescopes such as the Euclid Space Telescope and the Nancy Grace Roman Space Telescope are expected to enable many more such detections.