If you’re inclined to worry about things that are still far off in the future, you might want to stop reading. Astronomers are studying a star that has apparently consumed one of its planets — a fate that is likely in store for Earth in five billion years or so.
The BBC reports that an international team of scientists made the discovery using images from the Hobby Eberly telescope at the McDonald Observatory in Texas.
The star, known by the less-than-poetic moniker BD+48 740, is a red giant. That means it’s expanding in size as its core gets hotter. Scientists expect the same thing to happen to our sun billions of years from now.
Artists’s rendition of a red giant “devouring” a nearby planet. (NASA)
The astronomers studying BD+48 740 found that it contains an unusually high concentration of lithium. Stars destroy lithium over time, and a red giant is old by definition, so scientists determined the lithium was likely produced by the heat created when a planet smashed into the star. Supporting that theory, the scientists also found another planet orbiting the star has an extremely elliptical orbit. That suggests it may have been shifted into its current course by a blast of energy when its sister planet dove into the star.
Red giants are red because their surfaces are cooler than they were in their younger, yellower days. As they wind down their lives, the stars expand and become less dense. In the case of our sun, it will probably get large enough to encompass the solar system’s innermost planets, including Earth.
Fortunately, five billion years is way too long for most of us to wrap our minds around, so hopefully not too many of us will lose sleep thinking about the new discovery.
Hobby Eberly photo credit: EricandHolli at the English language Wikipedia