An article published in the journal “Science” reports the discovery of a compact object within the globular cluster cataloged as NGC 1851 whose nature is uncertain because mass estimates place it on the border between a neutron star and a black hole. A team of researchers used observations conducted with the MeerKAT radio telescope to identify traces of a binary system composed of a so-called millisecond pulsar and the mysterious compact object. The estimated mass for this object is between 2.09 and 2.71 times the Sun’s, so it could be a massive neutron star or a small black hole.