Two articles, one published in “The Astrophysical Journal Letters” and one published in the journal “Monthly Notices of the Royal Astronomical Society”, describe as many research on the supernova remnants known as RCW103. At its center a neutron star formed called 1E 161348-5055 – or simply 1E 1613 – that has been puzzling astronomers for decades for its abnormal behavior. Now two teams independently offered the same explanation: the neutron star has the characteristics of a magnetar.

RCW103 is about nine thousand light years from Earth and we see the remains of the supernova as they appear about two thousand years after the explosion. A star with an estimated mass about ten times that of the Sun exploded and the remaining core, with an estimated mass about one and half times that of the Sun, compacted into a sphere about 20 kilometers across.

This sphere is a neutron star that showed behaviors that so far astronomers struggled to explain. This object’s emissions are abnormal because its X-ray emissions are of a very rare type for such young neutron stars, those of radio waves are almost absent while they’re typical of young pulsars and X-rays show a periodic signal of 6.67 hours, an extremely slow time for a pulsar.

New data came decades later on June 22, 2016, when NASA’s Swift space telescope’s Burst Alert Telescope (BAT) instrument detected an X-ray flash that lasted only 10 milliseconds but of considerable intensity from RCW103. It’s a flash typical of magnetars, neutron stars that have an incredibly intense magnetic field, even a thousand times more powerful than that of normal young neutron stars.

Two different teams started working on that hypothesis: one led by Antonino D’Aì of the National Institute of Astrophysics, Italy, used the Swift space telescope but also examined RCW103 near infrared and optical with the GROND instrument mounted at ESO’s observatory in La Silla, in Cile and another one led by Nanda Rea of the University of Amsterdam used NASA’s Chandra and NuStar space telescopes.

Both teams detected in the neutron star 1E 1613 characteristics that made them classify it as a magnetar. The oddity is represented by its periodic signal, which seems to be its rotation period. Pulsars rotate at extremely high speeds immediately after their formation and slow down over time but this one is only two thousand years old. It’s far too little to slow down to that point whereas the slowest magnetar found so far has a rotation every 10 seconds.

According to the leading theory to explain this strange neutron star, after the supernova explosion large amounts of ejected material accumulated again around the core that became the magnetar. The interaction between these materials and the extremely strong magnetic field might have slowed its rotation abnormally. They’ll need to find other magnetars that rotate at very slow speed to see whether 1E 1613 is unique or the first of that type of neutron stars.