YSU professor part of team observing star cluster mergers with Hubble

A Youngstown State University professor contributed to international research published in the journal “Nature” that observed the merging of star clusters in dwarf galaxies using the Hubble Space Telescope.

Patrick Durrell, a Distinguished Professor of Physics and Astronomy at YSU, was part of the team that captured images showing this process. Scientists had long theorized that smaller star clusters could move toward the center of a galaxy and combine into a nuclear star cluster, but direct visual evidence had been limited.

“These are some of the clearest images ever captured of this process actually taking place,” Durrell said in a university release. “We’ve known this could happen, but now we have direct visual evidence.”

The study, titled “Evidence of star cluster migration and merger in dwarf galaxies,” involved using short observing “snapshots” from Hubble to collect data. The initial goal was to catalog star clusters in numerous smaller galaxies.

“But when we started looking closely at the images, we saw something unexpected,” Durrell said. “Some of these galaxies had strange-looking structures in their centers, what looked like the leftovers from two star clusters smashing into each other.”

The team then used computer simulations that aligned with the Hubble observations, supporting the theory that nuclear star clusters can form through the merging of older clusters migrating inward, in addition to new stars forming at a galaxy’s center.

Durrell helped lead the planning and setup of the Hubble observations for the research, coordinating the technical aspects for over 70 galaxy observations. He has collaborated with the research group for more than a decade on various astronomy projects.

“This kind of discovery shows how astronomers at universities like YSU are contributing to big, international science,” he said.

The research underscores the work being done within YSU’s Department of Physics, Astronomy, Geology, and Environmental Science.