Science
Astronomers discover first extragalactic globular cluster stellar stream
Researchers used archival Hubble data to identify a stellar stream in galaxy UGC 9050-Dw1, providing a new method to map dark matter.
The short version
- An international team of astronomers identified the first globular cluster stellar stream outside the Milky Way in the ultra-diffuse galaxy UGC 9050-Dw1.
- By modeling the gravitational pull acting on the stream's stars, researchers estimated the host galaxy's total mass and dark matter distribution.
- The discovery demonstrates a novel approach for measuring dark matter in distant galaxies using optical telescopes.
Key facts
- The discovered stellar stream is located in galaxy UGC 9050-Dw1, roughly 115 million light-years from Earth.[ScienceDaily]
- The findings were published on August 12, 2026, in the journal Nature.[ScienceDaily]
- Researchers identified the faint arc using archival Hubble Space Telescope images and confirmed the detection with ground-based telescope data.[ScienceDaily]
- The study was co-led by Julie Kiel Holm of the University of Copenhagen and Sarah Pearson of the Technical University of Denmark.[ScienceDaily]
- Computer simulations testing various globular cluster and dark matter configurations matched the observed shape of the stellar stream.[ScienceDaily]
What remains uncertain
- Astronomers continue to debate whether observed gaps or clumps in Milky Way stellar streams are caused by passing concentrations of dark matter.[ScienceDaily]
Sources
- A ghostly ribbon of stars reveals hidden dark matterScienceDaily - Science