The Sun is going to kill us. Not anytime soon, but it will kill us. At the moment the Sun keeps itself going by fusing hydrogen into helium and other heavier elements, but in five or so billion years it is going to run out of hydrogen. When that happens, the Sun will make a desperate attempt to keep going by fusing helium. During this period it will swell to a red giant, likely so large that it engulfs the Earth, baking it to a crisp in its diffuse hot atmosphere.
It’s generally been thought that if the Sun swells beyond the orbit of Earth, the atmospheric drag will cause our little world to spiral into the Sun. The inner solar system simply can’t survive the red giant stage of our star, and so will be consumed in the end. But this might not be the case, as a new study in Nature shows.
Astronomers in Hawai’i have found an odd Jovian planet orbiting a red giant star. The planet, nicknamed Halla, orbits its star at half the distance of the Earth from the Sun. That in and of itself isn’t unusual. Astronomers have found lots of close orbiting jovian planets, known as hot Jupiters. What makes Halla unusual is that its star is in the later stage of its red giant stage.
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