14 DAY TRIAL // Astronomers are really curious about the fate in store for our solar system, and so many teams have taken many approaches to finding out what the future holds. Scientists at the University of Leicester say that studying white dwarfs is one of the best methods of knowing the Sun's future.
White dwarfs can be found all over the galaxy, as they are rather common. They represent the final stage of evolution in the life of Sun-like stars, which makes them extremely relevant to studies about our own solar system.
When normal stars reach the end of their burning cycles, they tend to swell up, in an evolutionary stage called a red giant. During this period, experts say, our Sun will inflate until its surface exceeds the orbit or Earth, perhaps even Mars.
Once this stage is completed, the outer layers of the Sun's atmosphere will dissipate, potentially forming a nebula. The remaining core will shrink to a diameter smaller than that of Earth. However, the newly-formed white dwarf will be very dense.
This process is known to take place all over the galaxy and beyond, so Leicester researchers are hoping to learn more about our solar system by analyzing such objects in detail. Department of Physics and Astronomy PhD student Nathan Dickinson is leading the work.
He is focusing his attention on determining whether the heavy metals telescopes detect around white dwarfs are produced by the stars themselves, by surrounding clouds, or were gathered as exoplanets were destroyed during the red giant phase of stars.
Data from the Hubble Space Telescope indicate the presence of oxygen, nitrogen, silicon and iron in white dwarfs. This is especially true for older ones that have surface temperatures of just 25,000 degrees, Science Daily reports.
“Understanding whether the extra material in hot white dwarfs comes from torn up planets is important. It can give us an idea of how these ancient planetary systems evolve as the star ages, so we get a fuller picture of how solar systems die,” Dickinson says.
“Being the end point of the life cycles of most stars, white dwarfs are among the oldest objects in the galaxy, so they can tell us about what were in the oldest solar systems,” the expert goes on to say.
“Given that the Sun will end its life as a white dwarf, this could tell us what could ultimately happen to our solar system. Working at the forefront of this scientific area is extremely exciting,” he concludes.