Scientists capture moment star tears itself apart

Scientists have captured the moment a massive star 160 million light years from Earth was obliterated as it blew itself apart.

Astronomers watched the incredible event using telescopes in California used for tracking unusual events.

The giant fireball is the earliest-ever observation of a supernova — just three hours after an explosion.

Scientists were able to see the radioactive stardust scattering across space and determine what happened just before the violent blast.

Supernovae — known to be the most violent blasts in space — mark the death of massive stars.

They produce the same amount of energy as trillions of nuclear bombs detonating at the same time.

The rare event took place in a nearby galaxy called NGC 7610.

Shortly after its discovery on Oct. 6, 2013, different telescopes from the Intermediate Palomar Transient Factory (iPTF) were used to observe it.

An analysis of the information gathered shows it was a red supergiant exploding into a type II — the most common form of supernova.

A red supergiant is an aging star that has consumed its core’s supply of hydrogen fuel.

Helium has accumulated in the core, and hydrogen is now undergoing nuclear fusion in the outer shells.

These shells then expand, and the now-cooler star takes on a red color. They are the largest known stars.

The researchers also found evidence the star was encircled by a disk of matter that had been created in the year before its explosion.

In its final days, the star had been rapidly ejecting lots of material — losing mass before the collapse.

Previously scientists had only been able to study supernovae several days after the event.

Typically, they occur when a massive star — more than eight times the mass of the sun — runs out of fuel and collapses to form a hot relic called a neutron star.

Their extreme brightness allows them to be seen in distant galaxies.

But observers cannot pick up this optical emission until several hours or days after the explosion, so a supernova’s first moments are shrouded in mystery.

Experts believe that our own planet was formed following a supernova, the Big Bang.

Our own sun will also explode in several billion years.

Astrophysicist Dr. Ofer Yaron, of the Weizmann Institute of Science in Rehovot, Israel, said: “Why and how massive stars explode as supernovae is one of the outstanding open questions in astrophysics.

“Massive stars fuse light elements into heavier ones in their core. During the final years of their lifetime, these stars burn heavy fuel, the fusion products of hydrogen and helium, until an iron core grows and ultimately collapses.

“Stellar evolution in these final years, which sets the initial conditions for the final collapse and explosion of such stars, is poorly understood.

“Direct observation of these processes is challenging, as stars in these brief final stages are rare.

“Statistically, it is very likely that not even a single star that is within one year of explosion currently exists in our galaxy.”

He added: “Here we report the discovery of the supernova a mere three hours after explosion.

“Our rapid follow-up observations — which include multi-wavelength photometry and extremely early spectra — map the distribution of material in the immediate environment of the exploding star and establish it was surrounded by circumstellar material that was ejected during the final year prior to explosion at a high rate.

“The observations indicate it was a regular type II supernova; thus, the finding that the probable red supergiant progenitor of this common explosion ejected material at a highly elevated rate just prior to its demise suggests that pre-supernova instabilities may be common among exploding massive stars.”