They observe, for the first time, the magnetic field of a SUPERNOVA
Is 50,000 times weaker than a fridge magnet
Image of the 1987a Supernova obtained with the Hubble Space Telescope. You can see the inner ring interacting with the material expelled by the explosion. Image credit: NASA, ESA, R. Kirshner and P. Challis (Harvard-Smithsonian Center for Astrophysics)
For the first time, astronomers have directly observed magnetism in one of the most studied objects in astronomy: The remains of the 1987 Supernova (SN 1987a), a dying star that appeared in our skies more than thirty years ago.
In addition to being an impressive achievement, detection provides information on the early stages of the evolution of supernova remnants and cosmic magnetism within them.
“The magnetism we have detected is about 50,000 times weaker than a fridge magnet,” explains Bryan Gaensler, the study’s leader, in a statement. And we’ve been able to measure this from a distance of about 1.6 million trillion kilometers. This is the earliest possible detection of the magnetic field formed after the explosion of a massive star. ”
The finding has been published in the Astrophysical Journal. SN 1987a was discovered in February 1987 at the then observatory south of the University of Toronto in northern Chile. It is found in the Great Magellanic Cloud, a dwarf galaxy, at a distance of 168,000 light-years from the Earth. It was the first supernova with a naked eye that was observed since the astronomer Johannes Kepler witnessed one more than 400 years ago.
In the thirty years since its discovery, the material ejected by the explosion, as well as the shockwave, have been traveling outward through the gas and dust that surrounded the star before it exploded. Today, when we look at the remnant, we see rings of material ignited by the expanding debris and the shockwave of the supernova.
Using the Australia Telescope Compact Array (ATCA), the Gaensler team observed the magnetic field studying the radiation from the object. When analyzing the properties of this radiation, they were able to trace the magnetic field.
What they discovered was that the magnetic field of the remnant was not chaotic, but it showed a certain degree of order. Astronomers know that as the remnants of a supernova age, their magnetic fields stretch and line up in orderly patterns. Therefore, the team’s observations show that this process can begin in a relatively short period, as much in thirty years.