A Tour of SGR 1745-2900

Narrator (April Hobart, CXC): In 2013, astronomers announced they had discovered a magnetar exceptionally close to the supermassive black hole at the center of the Milky Way using a suite of space-borne telescopes including NASA's Chandra X-ray Observatory.

Magnetars are dense, collapsed stars -- called "neutron stars" -- that possess enormously powerful magnetic fields. This magnetar, which astronomers named SGR 1745-2900, could be as close as two trillion miles from the black hole at the center of the Milky Way. While this may sound like a large distance, it is not in astronomical terms. In fact, this magnetar is by far the closest neutron star to a supermassive black hole ever discovered and is likely in its gravitational grip.

Since its discovery two years ago when it gave off a burst of X-rays, astronomers have been actively monitoring SGR 1745-2900 with Chandra and the European Space Agency's XMM-Newton. A new study uses these observations to reveal that the X-ray output from SGR 1745-2900 is dropping more slowly than for other magnetars, and its surface is hotter than expected.

What is causing this unusual behavior? The researchers propose the surface of the magnetar is being bombarded by charged particles. These particles may be trapped in twisted bundles of magnetic fields. This scenario could explain both the slow decline in X-rays as well as the hotter-than-usual surface temperature of SGR 1745-2900. Scientists will continue to study SGR 1745-2900 to glean more clues about what is happening with this magnetar as it orbits our Galaxy's giant black hole.