The heaviest neutron star on record is 2.35 times the mass of the sun
The record breaker owes its massive success to infalling gas from a companion star
![illustration of a neutron star that became a pulsar next to an orbiting star](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2022/07/071822_kc_neutron-star_feat.jpg?fit=1030%2C580&ssl=1)
So much gas from an orbiting star (illustrated in orange) fell onto this neutron star (white with green and purple beams) that it began to spin fast, becoming a pulsar, and also grew to a record-breaking mass.
Cruz deWilde/NASA Goddard Space Flight Center