Many millions or billions of years ago, a gargantuan star in the constellation Sagittarius called J1808 ran out of fuel, collapsed under its own weight, and exploded.
Explosions such as these are common in space; scientists know that they are part of a process that transforms the mighty suns into crushed neutron stars – the smallest and most dense stars in the universe. What astronomers were intrigued about by J1808 today is the fact that it is still exploding and apparently souls our galaxy with some of the most intense light bursts ever discovered.
On August 20, 2019, a special neutron star telescope aboard the International Space Station (ISS) recorded a fusion bomb on J1
"This explosion was exceptional," Peter Bult, an astrophysicist at NASA's Godard Space Flight Center, and lead author A recent explosion study published in writings of the Astrophysical Journal Letters said in a statement. "We see a two-step brightness change that we believe is caused by the discarding of separate layers from the surface [star’s] and other features that will help us decode the physics of these powerful events."
J1808 is a pulsar or a neutron star that rotates extremely fast and emits powerful electromagnetic radiation from both poles. Stars like this rotate so fast (the J1808 completes about 400 spins every second) that the rays of energy at their poles seem to pulsate like strobe lights every time they point to Earth.
Like a black hole, the powerful gravity of a neutron star can stably draw huge amounts of surrounding matter, which collects in an extensive rotating disk at the edge of the star (this is called an "accumulation disk"). According to the authors of the new study, the J1808 appears to have spent a long time sucking up hydrogen gas from a mysterious celestial object with which it shares a binary orbit. This object, larger than the planet but smaller than a star, wins the indescribable cosmological title 'brown dwarf'.
The massive explosion observed on August 20 appears to be the result of a long, one-sided relationship between J1808 and its brown partner, researchers write. The neutron star appears to have sucked in so much hydrogen from its neighbor over the last few years that gas becomes a superhot, super-tight "sea" that begins to fall in and cover the star's surface. The heat from the star warmed the sea so much that a nuclear reaction began, causing the hydrogen nuclei to merge into helium nuclei. Over time, this newly formed helium creates a second layer of gas around the star's surface, which extends several meters deep, the researchers wrote.
"Because the helium layer is several meters deep, conditions allow helium nuclei to merge into carbon," study co-author Zaven Arzoumanian, also with NASA, said in a statement. "Then the helium erupts and unleashes a thermal
Researchers believe that the explosion of August 20 occurred when such a fireball quickly swept away the hydrogen and helium layers surrounding the star, causing a double flash of intense bright x-ray, (J1808 and his partner are located about 11,000 light-years from Earth, which is pretty close, cosmically.)
This interpretation of the explosion fits in with the ISS, but leaves one important detail. After the first two spikes of X-ray energy, the pulsar released a third, slightly smoky blast that was about 20% brighter than the normal flicker of the star, it is unclear what mechanism triggered that last blast of energy, researchers say.
Originally published on by Live Science .