Staff Editor
“Magnetar” magnetic stars are rare rogue examples of stars gone wild. When one of them explodes, the energy released is insane. When GRB 200415A blew up, it released more energy than our sun Sol “does in 100,000 years” and did it in “slightly more than a tenth of a second.”
Magnetar explosion GRB 200415A
The explosion of this magnetar was so intense that the event itself was given a name, GRB stands for “Gamma Ray Burst.” In April of 2020, the first observations of it were picked up by the Fermi Gamma-ray Space telescope.
What astronomers weren’t expecting is that the Atmosphere Space Interactions Monitor installed in the International Space Station caught it, too. ASIM captured better data.
During the brief instant of explosion, “astronomers observed exceptionally short oscillations in brightness.” That was something they had never seen before. Neutron stars are strange to start with but even the eruption of a magnetar doesn’t flash that fast.
The Astronomers don’t like to admit that the weather guys got a better look at what was happening with gear meant to study Earth’s atmosphere from above. The pros were using equipment that was way too sensitive.
What scientists call a Magnetar is a rare type of neutron star and only around 30 have been cataloged, so far. Neutron stars in general are extremely dense. A few more molecules and they would collapse into black holes and disappear from the universe. That makes them the most massive objects which could possibly exist.
Add to that “magnetic fields of at least a hundred billion Teslas.” The magnets inside the Large Hadron Collider are like the ones on your fridge by comparison. The magnetic field coming from a rotating neutron star is “10 billion times” larger.
Not an eruption
Astronomers are used to seeing “eruptions” on neutron stars and even on a magnetar or two. Those last “a few tenths of a second” and regularly “saturate” observing equipment with too much energy, “preventing detailed study.”
When they caught the flash from GRB 200415A with the Fermi Gamma-ray Space telescope it didn’t tell them a whole lot, and looked like another eruption. They didn’t find out it was a full fledged explosion until later.
The exploding magnetar showed up on the ISS instruments and they weren’t even looking for it. They were looking down at Earth for the “transient luminous events” that occur above thunderstorms. They happened to be looking in just the right direction to catch the explosion “out of the corner of its eye.”
Even better, they “provided more useful data than the purpose-built equipment.” Because the signal flashes so fast, the “amplitude rapidly decays and becomes embedded in background noise.”
Another thing that helped keep the ASIM instruments from overloading, GRB 2001415 happens to be “the most distant magnetar eruption detected.” It comes all the way from “a star-formation region of the galaxy NGC 253, in the Sculptor group.” ASIM picked up “two quasi-periodic oscillations (QPOs) of 2,132 and 4,250 Hertz respectively.”
Even though they were embarrassed at getting scooped by meteorologists, who don’t even study meteors, Astronomers started throwing a party. “Seen in perspective, it has been as if the magnetar wanted to indicate its existence to us from its cosmic solitude, singing in the kHz with the force of a Pavarotti of a billion Suns,” Professor Victor Reglero of the University of Valencia exclaimed.
