From across the Milky Way galaxy, something has been sending out signals.

Every two hours or so, a pulse of radio waves ripples through space-time, appearing in data going back years. Now a team of astronomers led by Iris de Ruiter of the University of Sydney has identified the source of this mystery signal – and it’s something we’ve never seen before.

Around 1,645 light-years from Earth sits a binary star system, containing a white dwarf and a red dwarf on such a close orbit that each revolution smacks their magnetic fields together, producing a burst of radio waves our telescopes can detect. This source has been named ILT J110160.52+552119.62 (ILT J1101+5521).