Ideas, Inventions And Innovations Extraordinary Magnetar Discovered Rotating Every 1.4 Seconds Oh 12, 2020, astronomers detected a new magnetar with NASA's Neil Gehrels Swift Telescope. This is only the 31st known magnetar, out of the approximately 3,000 known neutron stars. After follow-up observations, researchers determined that this object, dubbed J1818.0-1607, was special for other reasons. First, it may be the youngest known magnetar, with an age estimated to be about 500 years old. This is based on how quickly the rotation rate is slowing and the assumption that it was born spinning much faster. Secondly, it also spins faster than any previously discovered magnetar, rotating once around every 1.4 seconds.