…a type of neutron star whose magnetic field lines are so strong, they squish atoms into thin, pencil-like shapes.https://astronomy.com/news/2019/10/merging-stars-may-create-the-universes-most-powerful-magnets
Stellar mergers as the origin of magnetic massive starshttps://www.nature.com/articles/s41586-019-1621-5
Strong magnetic fields are produced in the simulations, and the merged star rejuvenates such that it appears younger and bluer than other coeval stars. This can explain the properties of the magnetic ‘blue straggler’ star τSco in the Upper Scorpius association that has an observationally inferred, apparent age of less than five million years, which is less than half the age of its birth association10. Such massive blue straggler stars seem likely to be progenitors of magnetars, perhaps giving rise to some of the enigmatic fast radio bursts observed11, and their supernovae may be affected by their strong magnetic fields12.
That paper is a bit overly expensive though, right?