On March 19, NASA’s Swift Burst Alert Telescope witnessed an extraordinary burst of light 7.5 billion light-years away from Earth, followed by an afterglow 2.5 million times more luminous than the most luminous supernova ever recorded.

The burst of light was caused by the death of a star located in the constellation Boötes, and is the brightest such phenomenon ever observed. Lucky observers who happened to look in the right place, at the right time witnessed the only object visible to human eye from such a distance.

The gamma-ray explosion was the result of the violent collapse of a massive star running out of nuclear fuel, and according to scientists reanalyzing the bright emissions, it produces energy across the entire electromagnetic spectrum.

When a star runs out of nuclear fuel, the core of the star collapses and forms what is known as a ‘black hole’ or neutron star, while at the same time, it releases an enormous amount of high-energy gamma rays at unimaginable speeds and forces.

According to scientists, the reaction doesn’t stop here: when the gamma rays reach nearby interstellar clouds, they often generate afterglows, due to the fact that the particles released from the gamma ray explosion heat the gas in these clouds. These are considered to be the brightest explosions in the entire Universe.

In a paper set to appear in Thursday’s edition of the journal Nature, Judith Racusin of Penn State University, together with a team of 92 scientists, explained that the amazing brightness which they’ve been studying came from an energetic jet of such particles aimed directly at Earth.

GRB 080319B is just one of the four such observations made by Swift that day. “This burst was a whopper,” Swift principal investigator Neil Gehrels of NASA’s Goddard Space Flight Center in Greenbelt, Md. said at the time. “It blows away every gamma ray burst we’ve seen so far.”