<Li> SGR 1900 + 14, located 20,000 light - years away in the constellation Aquila . After a long period of low emissions (significant bursts only in 1979 and 1993) it became active in May--August 1998, and a burst detected on August 27, 1998 was of sufficient power to force NEAR Shoemaker to shut down to prevent damage and to saturate instruments on BeppoSAX, WIND and RXTE . On May 29, 2008, NASA's Spitzer telescope discovered a ring of matter around this magnetar . It is thought that this ring formed in the 1998 burst . </Li> <Li> SGR 0501 + 4516 was discovered on 22 August 2008 . </Li> <Li> 1E 1048.1 − 5937, located 9,000 light - years away in the constellation Carina . The original star, from which the magnetar formed, had a mass 30 to 40 times that of the Sun . </Li> <Li> As of September 2008, ESO reports identification of an object which it has initially identified as a magnetar, SWIFT J195509 + 261406, originally identified by a gamma - ray burst (GRB 070610). </Li>

What is a magnetar and how strong is it