A magnetar may have actually boosted the explosion of an extremely bright supernova. Scientists have found that highly magnetized, rapidly spinning neutron stars could explain the energy source behind two unusual stellar explosions.
Supernovae occur at the end of a star's life, when it explodes with a brilliant burst. Supernovae themselves usually shine a billion times brighter than the sun. However, there's a class of supernovae called super-luminous supernovae (SLSNe). These can be as much as 10 to 100 times brighter than normal supernovae. However, researchers aren't quite sure what the energy source is for this super-luminosity.
In this latest study, the researchers set out to find out the answer to what causes super-luminous supernovae. They proposed that two recently discovered SLSNe were created in part due to the rotation energy lost by a newly born magnetar.
The two super-luminous supernovae in question are called SN 2011kl and ASASSN-15lh. Both can be found in the very distant universe, and both are extreme cases of SLSNe. SN 2011kl was first found in 2011 and is the first supernova to have an ultra-long gamma-ray burst that lasted several hours. The second supernova was discovered in 2015 and may just be the most luminous and powerful explosion ever seen at 500 times brighter than a normal supernovae.
In order to learn a bit more about these supernovae and see if they were the result of a magnetar, the researchers performed numerical hydrodynamical calculations. The researchers found that for ASASSN-15lh, there was a magnetar source with physically allowed properties of magnetic field strength and rotation period. This avoided the prohibited realm of neutron-star spins that would cause the object to simply break up.
So what does this mean? It's very possible that magnetars could be behind the two supernovae. With that said, the calculations will need to be confirmed with further observations. Researchers will have to examine material ejected by the supernova when it becomes thin. This will allow the scientists to probe the inner part of the exploding object and learn a bit more about its origin and evolution.
The findings reveal a bit more about super-luminous supernovae. This, in turn, may tell researchers a bit more about the evolution of stars.
The findings are published in the January 2016 journal The Astrophysical Journal Letters.
