A magnetar’s magnetic field is so strong that it can crack open the star’s surface to release bursts of energy visible across billions of light-years & astronomers have found a star that might be about to go magnetar https://scientificamerican.com/article/this-bizarre-star-could-become-one-of-the-strongest-magnets-in-the-universe/
This Bizarre Star Could Become One of the Strongest Magnets in the Universe

Magnetars possess magnetic fields that are trillions of times stronger than those of ordinary stars. Now we might have seen one of these extraordinary objects about to form

Scientific American