HARROW: Scientists using NASA’s Kepler space telescope – known as the K2 mission – have spotted strong evidence of a tiny, rocky object being torn apart as it spirals around a white dwarf star.
This discovery validates a long-held theory that white dwarfs are capable of cannibalising possible remnant planets that have survived within its solar system.
“We are for the first time witnessing a miniature ‘planet’ ripped apart by intense gravity, being vaporised by starlight and raining rocky material onto its star,” said Andrew Vanderburg from the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts in a Nasa statement.
As stars like our Sun age, they puff up into red giants and then gradually lose about half their mass, shrinking down to 1/100th of their original size to roughly the size of Earth.
This dead, dense star remnant is called a white dwarf.
The discovered devastated object formed from dust, rock, and other materials is estimated to be the size of a large asteroid and is the first planetary object to be confirmed transiting a white dwarf.
It orbits its white dwarf, “WD 1145+017”, once every 4.5 hours.This orbital period places it extremely close to the white dwarf and its searing heat and shearing gravitational force.
A research team led by Vanderburg found an unusual, but vaguely familiar pattern in the Kepler data.
The analysis indicated a ring of dusty debris circling the white dwarf what could be the signature of a small planet being vaporised, the authors noted.
“The eureka moment of discovery came on the last night of observation with a sudden realization of what was going around the white dwarf. The shape and changing depth of the transit were undeniable signatures,” explained Vanderburg.
