Climate change apart, Earth’s long-term future is bleak. When the Sun makes use of up the hydrogen gasoline in its core, fusion will grind to a halt, the core will contract and the star’s outer layers will develop previous the orbit of Mercury. Earth will seemingly be engulfed by the evolving purple large in about 8 billion years because the Sun ultimately turns into a white dwarf.
But what about Jupiter and the outer planets? Simulations point out planets at Jupiter’s distance can, in reality, survive a star’s purple large phase, however observational proof has been missing.
Writing in Nature, a crew led by J.W. Blackman of the University of Tasmania has discovered simply such a system utilizing microlensing, the distortion of sunshine from a distant object by the gravity of a better physique in direct line of sight from Earth.
The microlensing occasion in query, often called MOA-201-BLG-477Lb, was found in 2010. Analysis of the sunshine curve indicated a foreground star with 0.15 to 0.93 solar lots. The information additionally instructed a planet between 0.5 and a couple of.1 Jupiter lots. Given estimates of the lensing star’s correct movement, the researchers have been in a position to predict the place it might transfer with respect to the background star after the decade-old microlensing occasion.
Using the Keck II telescope in Hawaii, the crew looked for the anticipated main-sequence lensing star, however no such star was discovered. Given the telescope’s sensitivity, that meant the lensing physique couldn’t be a predominant sequence star. A brown dwarf was dominated out as a result of the supply lots not less than 0.15 the mass of the Sun. The higher finish of the mass vary, nonetheless beneath the mass of the Sun, dominated out a black hole or neutron star.
The evaluation concluded that they had discovered a white dwarf and a surviving planet that “represents an analog to the end stages of the Sun and Jupiter in our own Solar System.”
“We determine this system contains a 0.53 ± 0.11 solar mass white dwarf host orbited by a 1.4 ± 0.3 Jupiter mass planet,” they write within the paper’s summary. “This system is evidence that planets around white dwarfs can survive the giant and asymptotic giant phases of their host’s evolution, and supports the prediction that over half of white dwarfs are predicted to have Jovian planetary companions.”