As scientists study life on earth, they are finding that many things have contributed to the development of life. While life has been found in some really unusual places under the sea, two of the most important requirements for most life are liquid water and oxygen. When planetary scientists look out at the many suns in the galaxy, they use sophisticated telescopes and technology to see if they can figure out which suns and planets might contain oxygen and water. One of the surprising and more easily detected areas of space to locate both of these important things has been within dying stars.
Stars in space are like out sun. Some are larger and some are smaller. Our own sun is considered to be a medium-sized star. When we try to look at stars in space, the light from the stars can be so bright, that it blocks out any possible planet that might be circling around the star. Even with some of the most powerful telescopes, it is almost impossible to detect any potential planets. This makes it difficult to try to detect oxygen, when we can’t even see the planet.
When some stars begin to die, they become white dwarfs. The light from the white dwarfs is a lot less than when it was a regular sun. Planetary scientists have first started focusing on white dwarfs to see if they can detect planets that might be in orbit around them. When a planet orbits around a sun, including a white dwarf, both objects can be affected by the mutual gravity. This can cause the white dwarf to have a bit of a ‘wobble’. The larger the planet near the white dwarf, the larger the wobble. This is the main way scientists are detecting a planet orbiting around a white dwarf sun.
Looking for a possible planet around a white dwarf can take a long time. But scientists also have to look for the right kind of planet, one that isn’t too close or too far away from the white dwarf. They have figured out that the right kind of planet has to circle the white dwarf at least every ten hours and has to be at least one million miles away from the white dwarf sun. Studying the atmosphere with high tech equipment can let the scientists know if there is oxygen on the planet.
While all of this sounds like an excellent plan, there is one big problem. Before a sun turns into a white dwarf, it expands and gets bigger. Any planets that are in the way are going to experience an intense heat and potentially burn off the atmosphere that might contain oxygen. Any planets that are discovered that have an atmosphere that contains oxygen would have to be a newer planet that came into the orbit after the white dwarf expanded.
New technologies are being developed that will give the scientists the chance to detect both oxygen and liquid water vapor within hours of discovery. So far, they haven’t found a planet that has both, but they are continuing to look and are hoping to find one soon.