Astronomers have, for the first time, claimed to have witnessed the destruction of a solar system at the mercy of its own star, in a foreshadowing of Earth’s own distant fate.
The initial observations that led to the findings came from NASA’s Kepler K2 mission, which has the task of monitoring stars for a dip in brightness when an orbiting body crosses its solar parent. In the current case, the star, which is a white dwarf (rather unimaginatively named WD 1145+017), registered a dip every 4.5 hours. This indicates that the object is in an orbit approximately 520,000 miles from the star, which is approximately double the distance between Earth and the Moon.
Additional observations were made by Whipple Observatory in Massachusetts, the MEarth-South telescope in Chile and the Keck Observatory in Hawaii. They discovered evidence of a number of other additional bodies of material, all of which were in orbits that lasted for a similar time period. The astronomers involved therefore believe this indicates the existence of an extended cloud of dust around the fragment and that the planet is being broken up due to its proximity to the White Dwarf. If this is correct, it represents the first direct, observable evidence of the effects on a planet of the heat and gravitational tides of such a star.
The planet is approximately the size of the US state of Texas, and Ceres, a dwarf planet in Earth’s own solar system. However, it isn’t going anywhere just yet; at its current rate of decay, it will take approximately one million years for the White Dwarf to totally destroy it. Thoughts of some kind of quick Death Star-like explosion remain in the realm of science fiction, although it is a nice coincidence that a planet-killer was observed for the first time in the same week that the first full-length trailer for the new Star Wars film, The Force Awakens, was released to an increasingly excited fan-base.
Andrew Vanderburg, of the Harvard-Smithsonian Center for Astrophysics, who was the lead author of the study, has called the new data a “smoking gun” that demonstrates a clear, evidential link between white dwarf pollution and the destruction of rocky planets. Writing in Nature, he went on to speculate that his team’s observations could mean humans have for the first time witnessed the fate of their home planet. “We might be seeing how our own solar system could be disassembled in the future,” he wrote.
Francesca Faedi, an astronomer at the University of Warwick, said the death of the star Vanderburg’s team observed may have sent planets in the distant solar system crashing into one another in a series of cosmic collisions that reduced them to rocks that resemble asteroids.
“It is extremely exciting that astronomers have recorded the final throes of a planetary system,” she explained in an accompanying article in Nature. Like Vandenberg, she thought it likely that this was a preview of our own solar system’s destruction: “Although Earth’s final days are a long way into the future, this research has allowed us a glimpse of the probably inescapable outcome.” She was slightly more colloquial when she spoke to Space.com, however, simply describing the news as “very cool”. It is hard for anyone interested in the cosmic mystery that is our home universe to disagree with that. Very cool.