A warm tremble shakes an ancient planet
It’s still early to say, but maybe it was discovered the first example of a “rejuvenated” planet. In the case, it would be a giant planet survived the red giant phase of its parent star and rekindled by matter lost by the dying star.
As in a hypothetical sequel science fiction film Youth of Paolo Sorrentino, also an old glory spatial overweight might find a bit of youthful vigor after a nice spa treatment …. According to a study recently published in the Astrophysical Journal Letters, in fact, in data from NASA’s Spitzer Space Telescope has discovered the first candidate for the category of planets called “rejuvenated”, previously hypothesized but never observed.
“When the planets are young, shine with an infrared light for the residual heat from their formation,” said Michael Jura of the University of California (UCLA), one of the authors of the new study. “As they age and cool, their glow disappears. The planets rejuvenated, however, at some point become visible again. ”
A therapy which will then undergo a planet on Sunset Boulevard to regain the essence of his youth? Years ago, some astronomers predicted that certain massive planets the size of Jupiter, could accumulate mass by the remains of their dying star guests.
As you know, stars like our Sun at the end of their existence swell enormously in a state defined as red giant, gradually losing about half of their mass. At the end it is bunched in a sort of skeleton stellar, called white dwarf. The material screened out from the dying star can fall back on the giant planets that many orbit at a distance.
Thanks to this unexpected nourishment, the giant planet could not only gain weight but also warm up because of digestive processes, namely the friction produced by material falling on the planet. The old, cold limbs of the planet would then shake by a deep conviction, detectable by astronomers as a light at the wavelengths of the ‘infrared.
The new study describes in fact a “dead” star, a white dwarf called PG 0010 + 280, around which a student at UCLA, Blake Pantoja, he accidentally discovered an unexpected infrared emission as he was sifting through the data of NASA’s Wide-field probe Infrared Survey Explorer (WISE). Verifying the observations made on the same star in 2006 by the Spitzer Space Telescope, the researchers found the same excess of infrared radiation, not previously noted.
To explain this excess, the scientists first suggested the presence of a ring of debris around the white dwarf, a record derived from the crushing gravity of asteroids that are too close to the star, finishing powder. But a whole series of elements have led to discard the possibility of the disc asteroidal. That left two possibilities: the presence of a small companion star never turned on, a brown dwarf, or – much more interesting possibility – a planet rejuvenated.
“I find that the most interesting part of this research is that the excess infrared can potentially come from a giant planet, although we still have a lot of work to do before we can say for sure,” says Xu Siyi UCLA and the European Southern Observatory in Germany. “If confirmed, it will be proof that some planets can survive the red giant stage of their parent stars and remain in orbit around the white dwarf.”
In the near future, the James Webb Space Telescope, successor to the Hubble, can probably distinguish between the glow produced by a ring of dust rather than a planet around a dead star. Meanwhile, the hunt for the source that rejuvenates the planets is not subsiding.