How big is a magnetar?
While some magnetars can be about the size of the Sun, the newly discovered one, NGC 1624-2 has a radius that’s 11.4 times the radius of the sun. That’s around 8 million kilometers! This massive star possesses a magnetic field 20,000 times stronger than the sun's and nearly 10 times stronger than that detected around any other high-mass star. While NGC 1624-2 is the most magnetic of all known massive stars, a few intermediate-mass stars have magnetic fields maybe twice as strong. The magnetic field of this magnetar is about 20,000 gauss at the surface of the star. Any normal magnetar might have a magnetic field of 10 trillion gauss, so the strength of NGC 1624-2’s field is much larger, around 500 million times larger. "The standard basis for comparison of how much magnetic field is present is the magnetic flux, which is equal to the strength of the magnetic field times the surface area of the star," astronomer Gregg Wade said. "In that case, the flux of NGC 1624-2 is almost 700 times larger than that of a typical magnetar.” In other words, if NGC 1624-2 were to suddenly reduce its size a certain amount, while retaining all of its magnetism, it would have a surface magnetic field of nearly 10,000 trillion gauss. The observations of NGC 1624-2 are what we need to teach us what’s really going on in the Universe.