1985C

1985C is a neutron star that is known for being the second-most massive neutron star discovered to date. It was observed during the 1980s, and its mass was initially recorded as approximately 1.366 solar masses. However, further observations in the following years determined its mass to be around 1.465 solar masses, making it the second-most massive known neutron star at that time.

Research on 1985C has also shed light on the properties of this object. It is believed to be a highly magnetized neutron star that emits X-rays due to the process of magnetized accretion from an circumstellar material. It was discovered while it was undergoing an outburst, classifying it as a Soft Gamma Repeater (SGR). Soft Gamma Repeaters are a class of neutron stars that expel massive bursts of energy in the form of electromagnetic radiation.

Observations of 1985C have also been used to study its rotation period, dichotomy, and lack of a precisely measured spin-down rate. This neutron star's observed rate of change of its rotation period is relatively slow compared to expectations based on mathematical models. The cause of its slow spin-down rate is a topic for debate among scientists.

To this day, 1985C remains a subject of scientific interest due to its unusual properties and the potential to provide insights into the complexities of these enigmatic objects. Its discovery has contributed significantly to our understanding of neutron stars, SGRs, and related high-energy astrophysics phenomena.