Given the enormity of space, it feels as though we learn something new about it every day. Today is no different: According to researchers from the Rochester Institute of Technology, they’ve found stars aligned like a blue pearl necklace along two elliptical galaxies. The finding came in a study sponsored by the Hubble Space Telescope, with the intention of studying little-known elliptical galaxies coalescing at the core of a dense galaxy cluster.

The “string of pearls” is 100,000-light-years-long and includes 19 young, blue stars spaced evenly at 3,000 light year intervals. The best part? It was a surprise find, not at all the point of the study.

“These data were originally taken for a completely different purpose—to study the bluish arcs on larger scales in the cluster,” said Chris O’Dea, professor in RIT’s School of Physics and Astronomy and a co-author on the paper. “We were not expecting to catch these two elliptical galaxies in this spectacular burst of star formation.”

As to what’s going on and why the stars are forming in this manner is still up for debate, but O’Dea and his colleagues have some ideas. Apparently, the phenomenon has been observed before, in two galaxies that are in the process of merging. They begin essentially playing “tug of war” with the “necklace” of stars. Grant Tremblay, a post-doctoral fellow at the European Southern Observatory in Garching, Germany is the lead author of the paper. He and his colleagues believe one of three possible scenarios explain the star formation:

• Merger—Coalescing galaxies triggered a reservoir of cold gas into star formation
• Cooling flow of gas—Hot gas from the X-ray atmosphere around the galaxies cooled into puddles of cold molecular gas and started to form stars
• Collision—A galactic collision created an X-ray shock catalyzing the star formation by compressing the gas and cooling the plasma.

Given that stars take a relatively short time to form (millions of years in a universe several billion years old), it’s rare to observe such an event. As they track the “string of pearls'” progress and determine the cause, they hope it will lead them to learn much more about elliptical galaxies.