SGR 1806-20 is a Magnetar, a type of neutron star with a very powerful magnetic field. It was discovered in 1979 and identified as a soft gamma repeater. SGR 1806-20 is located approximately 14.5 kiloparsecs (50,000 light years) away from Earth on the far side of the Milky Way in the constellation Sagittarius. It has a diameter of no more than 20 km and rotates around its axis every 7.5 seconds (the rotation speed on the surface is 30,000 km/h). As of 2016, SGR 1806-20 is the most strongly ma...