A supernova explosion first seen from Earth 436 years ago has come back to life for astronomers in a time-travel-like astronomical twist.

By observing light from supernova SN 1572 that was slowed on its trip to Earth by dust particles, scientists can watch the outburst now as it would have looked originally.

When the explosion first appeared in the sky in 1572, Danish astronomer Tycho

Brahe named it “Stella Nova” or “New Star” because it looked like an extremely bright star that hadn’t been there before. Astronomers today call it Tycho's supernova.

“Tycho Brahe was closer to the supernova idea than others,” said Oliver Krause of the Max Planck

Institute for Astronomy in Germany, and co-author of the study which appears in Nature Thursday. “He immediately recognized that this was an extraordinary event. He was really ahead of his time.”

Radio waves from remnants of the gases emitted by Tycho's supernova were first discovered in 1952, and in 1960, faint light was identified with an Earth-based telescope. Today when scientists aim their telescopes at the same spot, they see the gas left over from the supernova

(shown in image above). Krause's team used a new method to watch the supernova explosion as it would have looked in 1572.

They observed “light echoes” of the bang. These rays of light coming from the supernova are only just reaching Earth now because they took the long way home, bouncing off dust particles in the interstellar medium on their way. The team used this same method to study the origin of supernova remnant Cassiopeia A last year.

“Usually these objects happen very distantly. The only thing is the bright flash of the supernova and then it’s gone,” Krause said. “You cannot determine the progenitor, and you also cannot say what happens afterward. Now the nice thing here is this explosion happened a long time ago, and now its supernova remnant is visible.”

Using the

Subaru telescope on Mauna Kea, in Hawaii, the team took detailed measurements that revealed the chemical composition of the exploding star, and were able to determine that the supernova is of a class called “Type 1a.” These events occur when mass from a larger star pours onto a smaller white dwarf star, and eventually tips the dwarf over its weight limit, causing the star to collapse in a powerful explosion.

When SN 1572

first occurred, it puzzled most sky watchers. Many suggested that it was a comet, since those were the only other heavenly objects known to sometimes appear and disappear.

It was only until much later, in the early 20th century, that astronomers first understood that a supernova represents a star’s death.

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Image: MPIA/Spitzer Space Telescope/Chandra X-Ray Observatory /Calar Alto 3.5m Telescope

Video: Max-Planck Institute for Astronomy