The globular cluster NGC 1850 lies inside the Large Magellanic Cloud, a satellite galaxy of the Milky Way
Copyright: NASA, ESA and P. Goudfrooij (Space Telescope Science Institute); Processing: Gladys Kober (NASA/Catholic University of America)
Exploring the fine line between what constitutes a collection of stars and what defines a galaxy has been a challenging question in the field of astronomy. The distinction between the two has been blurred by the discovery of objects that defy easy classification.
While traditional galaxies are typically large, spiral structures containing billions of stars and surrounded by dark matter halos, there exist smaller formations known as globular clusters. These clusters, with populations ranging from tens of thousands to millions of stars, are gravitationally bound and exist within galaxies.
However, recent observations have revealed ultra-faint objects near the Milky Way, challenging the clear distinction between globular clusters and galaxies. These faint satellites, some containing as few as 60 stars, have raised questions about their classification and the presence of dark matter within them.
Studies like the Sloan Digital Sky Survey have deepened the complexity by uncovering more faint objects that may be galaxies, further complicating the categorization process. Researchers are now faced with the task of determining whether these compact, ultra-faint satellites are indeed galaxies, a task that could have significant implications for astrophysics and cosmology.
Ongoing research, such as the investigation conducted by William Cerny and his team, aims to shed light on these enigmatic objects. As the scientific community grapples with the definition of galaxies and the mysteries they hold, the boundaries between different cosmic phenomena continue to be redefined.
What are you reading?
Poets, especially Cortney Lamar Charleston’s collection It’s Important I Remember and Camonghne Felix’s manifesto Let the Poets Govern.
What are you watching?
Too much Alfred Hitchcock!
What are you working on?
I’m getting ready for the US launch of my book The Edge of Space-Time on 7 April!
Chanda Prescod-Weinstein is an associate professor of physics and astronomy at the University of New Hampshire. She is the author of The Disordered Cosmos and the forthcoming book The Edge of Space-Time: Particles, poetry, and the cosmic dream boogie
Mysteries of the universe: Cheshire, England
Spend a weekend with some of the brightest minds in science, as you explore the mysteries of the universe in an exciting programme that includes an excursion to see the iconic Lovell Telescope.
