A Hidden River of Stars: Discovering a Stellar Stream Around Galaxy M61 with the Rubin Observatory

Astronomers led by Aaron Romanowsky used the Vera C. Rubin Observatory to discover a faint, 50,000-light-year-long stellar stream around the spiral galaxy M61. The stream likely formed from a dwarf galaxy torn apart by M61’s gravity, possibly triggering its starburst and active nucleus. This finding previews Rubin’s ability to reveal countless faint galactic remnants, deepening understanding of galaxy growth and evolution.