Exotic Magnetar Caught on Tape

Scientists operating the largest optical wavelength observatory in the world, the Gran Telescopio CANARIAS (GTC), announce the discovery of the sixth-known magnetar. These weird cosmic objects are a special breed of neutron stars, which have incredibly strong magnetic fields emanating from their poles. Observing such structures in these wavelengths is very difficult, most often because of the massive distance these stars are located from Earth. The new magnetar, called SGR 0418+5729, had many of its properties investigated by the new observation effort, experts at the Instituto de Astrofísica de Canarias (IAC) announce on their official website.

Neutron stars, the source of magnetars, are space structures that are produced when a massive star, about 10 to 50 times the mass of our Sun, explodes into a supernova, at the end of its burning cycle. When this happens, the outer layers of the atmosphere are cast out into space, while the core of the star collapses under its own weight into a very small space. On account of these restrictions, electrons and protons collapse into neutrons, so as not to take so much space on their own. The matter making up these stars becomes incredibly dense, and the bodies begin venting off some of that matter as particles. Some of them begin producing incredibly large magnetic fields.

To get an idea of how impressive the level of density inside these stars is, consider that “stellar remnants concentrate a mass comparable to the one of the Sun within the volume of a sphere of only 30 kilometers of diameter, the space occupied by a large city,” explains Italian Institute of Astrophysics expert Paolo Esposito, who is also the principal investigator of the new study. “Magnetars do have a magnetic field thousand times stronger than that of normal neutron stars, millions of times superior that the most intense field that can be produced in our terrestrial laboratories. Indeed, these are the most powerful magnets in the Universe,” the expert adds.

The target of the new GTC investigations was not the magnetic field of the magnetar, but rather the impressive bursts of light that escape its surface when fractures form. These events are also caused by movements in the star's magnetic field, and the end-result is almost always an eruption of low-energy gamma rays. With the new data and future GTC studies, experts hope to be able to “understand how and where the emission originates, helping to clarify the basic physical characteristics of these ultra-strong magnetic fields,” Esposito explains. Full details of the work will appear in this week's issue of the respected scientific publication Royal Astronomical Society.