Astronomers Discover 1st Extragalactic Globular-Cluster Stream 115 Million Light-Years Away
Updated
Updated · Space.com · Aug 26
Astronomers Discover 1st Extragalactic Globular-Cluster Stream 115 Million Light-Years Away
3 articles · Updated · Space.com · Aug 26
Summary
Pearson and Julie Kiel Holm’s team confirmed Oyashio in UGC 9050-Dw1, making it the first stellar stream from a globular cluster found outside the Milky Way.
Archival Hubble and Canada-France-Hawaii Telescope data showed a faint curved ribbon linked to a matching globular cluster; thousands of simulations found that explanation fit better than lensing, dust or chance alignment.
The 3,000-light-year-class stream offers an unusually clean dark-matter probe because its ultra-diffuse host lacks Milky Way complications such as a central bar or Magellanic-Cloud-like satellites.
Modeling suggests UGC 9050-Dw1 contains far more dark matter than its sparse stars imply, and researchers say larger samples from Roman and Euclid could turn such streams into broader tests of dark matter.