The death of a star in a galaxy far, far away is giving astronomers insight into what the death of our sun will look like. In 5 billion years, scientists expect that our sun will evolve into a giant red star, over 100 times bigger than its current size. It will eventually die and turn into a small, white dwarf star. A team of researchers has been observing this process on a star known as the pi1 Gruis, the Daily Mail reports. The star is situated over 500 lightyears away from our galaxy. It has approximately the same mass as our sun and it’s dying.
Scientists say that pi1 Gruis depleted its hydrogen stores a long time ago. With no more energy to burn, the star began to get smaller and smaller. Its temperature also increased to over 100 million degrees. These high temperatures triggered the fusion of helium to atoms like carbon and oxygen. The extreme heat also caused the star to expand. It’s now more than 100 times larger than it was before.
Stars that go through this process are commonly called red giants.
According to the Daily Mail, scientists have not been able to get detailed images of the surface of one of these dying red stars until today. Astronomers used the ESO’s Very Large Telescope to examine the planet. During the examination, they found that convective cells dotted the planetary surface. Each of these cells measures beyond the distance between our sun and Venus. The sun in our solar system has these convective cells too, but they are much smaller and measure about 1,500 kilometers in diameter.
If scientists are pretty confident that our sun will die like the pi1 Gruis, it’s easy to wonder what will happen to life on Earth when the phenomenon occurs 5 billion years from now.
As Live Science reports, a 2008 study conducted by astronomers Klaus-Peter Schröder and Robert Connon Smith approximated that when it starts to die, the sun’s outer layers will expand to about 170 million kilometers. In doing so, they expect it to vaporize Mercury, Venus, and Earth. Because of increases in the sun’s luminosity, Earth’s oceans will have already started evaporating by the time our sun is ready to turn into a red giant. Nitrogen and carbon dioxide will more than likely end up dominating this planet’s atmosphere much like they do on Venus. There are disputes among experts on whether our atmosphere will be similar to Venus’ as that depends on our levels of volcanic activity and how active our plate tectonics will be that far into the future.
According to Live Science, if there are any humans left when our sun starts dying, their best hope will be to move to another planet. Mars could be a good option for a while because by that time scientists expect it to be in the sun’s “habitable zone.” But Mars’ viability as a home for human life won’t last forever. Our best bet then will probably be dwarf planets like Pluto on the edge of the solar system, and even certain comets/asteroids inside the Kuiper belt.