On May 29, 2023, the LIGO Livingston detector observed a signal from the merger of a neutron star and an unknown compact object, potentially a lightweight black hole. This discovery challenges the previously accepted mass gap between neutron stars and black holes. The researchers at the Max Planck Institute for Gravitational Physics played a crucial role in this groundbreaking finding. The improved waveform models, data-analysis methods, and detector technology allowed for this detection. The fourth observing run, which commenced in May 2023, is already off to a thrilling start, with promising prospects for more celestial observations and discoveries in the future.
https://www.mpg.de/21778967/0404-grav-mysterious-object-in-the-gap-152520-x