NASA's Kepler space telescope captured the wild explosion of a unique kind of dying star, gaining insight into this mysterious sort of supernova.
The death of an enormous star in the form of a supernova is one thing. It’s already the largest kind of explosion that takes place in all the cosmos.
But sometimes, these interstellar explosions occur with so much power and pent-up kinetic energy that the whole process takes place in just a tenth of the normal time. This rare event is known as a fast-evolving luminous transient (FELT).
Astronomers known little about these mysterious, awe-inspiring events. But now, in a rare event, NASA has revealed that the Kepler space telescope was able to capture a FELT.
A supernova like this one happens where there is a change in the core of a star, typically in one of two ways. The first, more common way (a core-collapse supernova) has five states.
First, the super-giant red star runs out of fuel to burn so its dense core collapses under its own weight. Second, the collapse of the star’s core creates a shock wave. This shock compressed for a couple of hours, which heats the enveloped star and creates a really bright flash of light.
The third step happens when the shock that’s compressing hits the surface. This contact blows the start apart. The core that is left becomes a neutron star, a compact atomic nucleus that has the same mass as the sun but is much, much smaller.
Fourth, the glowing surface of the dying star expands and makes the fireball brighter again. It keeps expanding and becomes 10 times the size of the original star in just a few short days.
Finally, those dispersed remains of the former star spread out over light years of space. They float and sweep up interstellar gas as they go, leaving behind a faint but beautiful glow.
The second kind of supernova, a white dwarf, happens when the star steals material away from a stellar companion that’s in close proximity to it. Once the mass of the white dwarf reaches around 1.4 times that of the sun, it can’t manage its own weight any longer, so it blows up. The same effect can occur when two white dwarfs merge.
Finally, apart from the standard two forms of supernova, there is the FELT star. This process is so rare and so speedy that astronomers know far less about it. What’s miraculous about the FELT star captured by Kepler — aside from the simple fact that Kepler was able to capture it — is that Kepler has the ability to accurately measure sudden starlight changes. And because of this precision, astronomers can create a new model for FELTs.
A study from the Australian National University done on the discovered FELT star and published in the Journal Nature Astronomy on March 26, 2018, suggests that this is “a new kind of supernova that gets a brief turbo boost in brightness from its surroundings.”
“We’ve discovered yet another way that stars die and distribute material back into space,” researcher Brad Tucker said. Perhaps now scientists will be able to learn a little more about this most mysterious sort of cosmic explosion.
For more from the wonderful world of space, check out some Mars facts that’ll teach you everything you ever wanted to know about the red planet. Then, see why the Tarantula Nebula more than lives up to its name.