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

In this artist's conception, a Ceres-like asteroid is slowly disintegrating as it orbits a white dwarf star. Astronomers have spotted telltales signs of such an object using data from the Kepler K2 mission. It is the first planetary object detected transiting a white dwarf. Within about a million years the object will be destroyed, leaving a thin dusting of metals on the surface of the white dwarf.

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 fate that will one day befall 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. The team found evidence of a rocky object orbiting the dead star, disintegrating as it went, because of 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 Earth’s sun, this will likely include Mercury, Venus and Earth. It will 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 neighboring 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.

Watch this dreamy animation of a black hole tearing apart a passing star

A new animation from the space agency shows what it looks like when a star gets torn apart by a black hole's huge gravitational pull. In this artist rendering, the star passes close enough for the black hole's gravity to take hold, and immense tidal forces rip the star to pieces. During this process — known as "tidal disruption" — some of the stellar debris is flung out into space, while most of it falls around the black hole and forms a huge gaseous disk.

The video is meant to illustrate a very real interaction between a star and black hole that was observed by three different X-ray telescopes. Known as ASASSN-14li, this black hole-star interaction is located in the center of a galaxy 290 million light years away. Astronomers think that ASASSN-14li has a mass that's about a few million times that of our own Sun.

 NASA | Massive Black Hole Shreds Passing Star, credits :NASA Goddard

Researchers were able to observe the stellar debris disc form around the black hole by looking at the X-rays surrounding ASASSN-14li . When the black hole destroyed the passing star, the debris that fell toward the hole was heated up to millions of degrees, glowing brightly with X-ray light. Three telescopes — including NASA's Chandra X-ray observatory — were able to measure these X-rays, as well as the presence of powerful winds moving outward from the black hole. As the debris disk heats up, it expels gases outward at super high speeds in the form of wind.

Getting too close to a back hole is bad news for anyone, not just stars. Black holes are so incredibly dense that nothing — not even light — can escape their gravitational pulls. Experts have theorized that if a person were to fall into one, they'd stretch into a long spaghetti-like tube before dispersing into numerous subatomic particles.

The Sun (our Star) 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.

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