Astronomers scouring the cosmos for new planets have made a chance discovery, identifying the rare eclipse of two brown dwarfs.

“This is a great example of scientific serendipity,” Adam Burgasser, a co-leading author on this study and a professor of physics at UC San Diego, said in a statement. “While searching for planets, we found an eclipsing brown dwarf binary, a system that is uniquely suited for studying the fundamental physics of these faint celestial objects.”