NASA/ESA Hubble Space Telescope image showing the glowing remains of a dying star
with a white dwarf at its centre
A new theoretical study has led to evidence that life may be present in habitable, earth-like planets which form as a result of dying stars. Astronomers believe that scientists may be able to detect these life-forms with ease as soon as the next decade using NASA's James Webb Space Telescope which is set to be completed in 2018.
When a star such as the Sun dies, it loses its outer layers, leaving just a hot core called a white dwarf, also known as a degenerative dwarf. These gradually cool and despite their sizes being comparable to the size of the Earth, they can retain heat long enough to warm a nearby planet for billions of years. Since a white dwarf is much smaller and fainter than the Sun, a planet would have to be much closer in to be habitable with liquid water on its surface. Professor Avi Loeb, theorist at the Harvard-Smithsonian Center for Astrophysics (CfA) suggests that "In the quest for extraterrestrial biological signatures, the first stars we study should be white dwarfs,". This is purely because detecting oxygen in the atmosphere (which, if found in large quantities, is indicative of the presence of plant life) is significantly easier as opposed to detecting oxygen levels in planets orbiting stars like our Sun. Professor Loeb estimates that observing 500 of the closest white dwarfs could lead to the discovery of at least one habitable planet, with conditions similar to that of Earth.
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