Scientists Observe Dead Star Eating its Own Solar System For First Time

One day, the Sun will run out of fuel. When that happens, the life-giving star will morph into a destructive burning force, swallowing up the Earth and other nearby planets, before leaving behind an ultra-dense core, which sucks in the remains of the solar system.

In a study published on Thursday in the journal Nature, scientists reported that they had observed for the first time this process of a destroyed planetary system feeding a dead star, which they said provides a glimpse of the distant future of the Earth.

The team of researchers, headed up by astronomer Andrew Vanderburg from the Harvard-Smithsonian Center for Astrophysics in Massachusetts, studied WD 1145+017, a white dwarf star residing in the Virgo constellation, which is around 571 light years away from Earth. They found evidence of a rocky object orbiting the dead star, disintegrating as it went due to the star's intense heat and gravitational pull. "This is something no human has seen before," said Vanderburg in a statement. "We're watching a solar system get destroyed."

A white dwarf refers to the burnt-out remnants left behind when a low-medium mass star—such as the Sun—runs out of hydrogen. The Sun generates its energy by a process of nuclear fusion, where hydrogen is converted into helium. Once the hydrogen runs out, the star enters its red giant phase, when it can swell up to 1,000 times its original size. Expanding red giants swallow planets that are too close—in the case of the Sun, this will likely include Mercury, Venus and Earth—and spend up to one billion years in this phase before collapsing in on itself to form a white dwarf. The gravitational pull of a white dwarf is 350,000 times as strong as Earth's gravity and can result in neighbouring stars or planets being broken up, with the mass from these bodies building up on the surface of the white dwarf.

The study was conducted using data collected by NASA's Kepler K2 mission. When observing the light emitted by WD 1145+017, the researchers found that the light was obscured roughly every 4.5 hours, suggesting some kind of debri or orbiting body that blocked the light out. Follow-up studies suggested that at least one and probably around six rocky bodies were orbiting the star, creating a trail of dust as the star's gravity slowly sucks them in.

Further analysis of the light emitted by the star showed that elements including calcium, iron and aluminium were found on its surface, suggesting that the rocky bodies were gradually disintegrating and their remains transferring onto the star's surface. The researchers estimated that some 8 million kilograms of matter were vaporized per second.

The Sun is estimated to run out of hydrogen in around five billion years time. When that happens, "the situation [observed in WD 1145+017] is something that's like to happen to our own solar system," Vanderburg told Nature.