The discovery of gravitational waves last year totally floored the world of science, but a new discovery could take our understanding of the phenomenon one step further. Scientists using the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) believe they’ve detected the first instance of gravitational waves produced by neutron stars colliding, instead of black holes as had been the case the last three times.

Scientists have seen this happen a few times since mid-August as the rest of the world was transfixed by the Great American Solar Eclipse. LIGO first made headlines back in February 2016 with the discovery of the long theorized gravitational waves due to merging black holes, and has made two additional similar discoveries since then. But this is a completely new finding since it involves neutron stars.

The stars are located in the galaxy NGC 4993, which is situated about 134 million light years from us in the constellation of Hydra.