Ultra-luminous X-ray pulsar NGC 300 ULX1 experienced unprecedented spin evolution, study finds

Using NASA’s Swift space telescope and NICER instrument aboard the International Space Station (ISS), astronomers have investigated the properties of an ultra-luminous X-ray pulsar known as NGC 300 ULX1. Results of this study, presented in a paper published May 9 on the arXiv preprint server, indicate that this object experienced an unprecedented spin evolution as its spin period decreased significantly during a timespan of four years.

Source:
https://phys.org/news/2019-05-ultra-luminous-x-ray-pulsar-ngc-ulx1.html