An international team of astronomers has discovered the first confirmed planetary system that possibly predicts the future of our solar system, when the Sun will have “eaten its bread” in about five billion years. It is a gas giant exoplanet larger than Jupiter, moving around a dead white dwarf star near the center of our galaxy.
The researchers, led by Dr. Joshua Blackman of the Australian University of Tasmania, who published in the journal Nature, accidentally detected the system with the Kek Telescope in Hawaii using the “gravitational microfiche” technique. The white dwarf is estimated to have about 60% of the mass of our Sun and its huge exoplanet (MOA2010BLG477Lb) has a mass 40% larger than Jupiter, 2.8 astronomical units away from its parent star.
“Our observations confirm that planets that are in orbit far enough away from their star can continue to exist after the death of the latter,” Blackman said. “Given that this system is analogous to our own solar system, it seems that Jupiter and Saturn may eventually survive after our Sun becomes a red giant, when it runs out of nuclear fuel and self-destructs,” he added.
On the other hand, this does not change the more or less prescribed fate of the Earth and the other planets close to the Sun. As said astronomer David Bennett of the American University of Maryland and the Goddard Space Flight Center of NASA , «the Earth’s future probably will not be so rosy, because it is much closer to the Sun. Only if humanity wanted to move to a satellite of Jupiter or Saturn, before the Sun burns our planet during its hot phase when it has become a red giant, could we remain in orbit around the Sun, although we would not we were now able to rely for a long time on the heat of a Sun like a cold white dwarf “.
A white dwarf is what is left of a star like the Sun. In the last stages of its life cycle, the star burns all the hydrogen in its nucleus and inflates like a balloon, turning into a red giant. He at some point collapses gravitationally inward, shrinking into a tiny white dwarf, remaining a dense star the size of just like an Earth-like planet. These stellar “corpses”, which abound in the universe, no longer have nuclear fuel to shine brightly, so they are faint and difficult to detect.
In the case of stars larger and heavier than the Sun, they end up, when gravitationally collapsing, turning into black holes or neutron stars. In our galaxy it is estimated that 95% of the stars will become white dwarfs. Scientists estimate that at least half of the white dwarfs have companion exoplanets and do not rule out that they may have host-friendly living conditions.