A blip recorded by the NASA’s Chandra X-ray Observatory has pointed astronomers to what might be the first planet detected passing across a star in a galaxy beyond our own — but we may not know for sure anytime soon.
The observation of an X-ray transit in the spiral galaxy M51, about 28 million light-years away in the northern constellation Canes Venatici, is reported in the journal Nature Astronomy.
Even if the detection of a planet in M51 goes unconfirmed, the Chandra observations demonstrate that X-ray transits could become a new method for tracking planets far beyond our solar system.
“We are trying to open up a whole new arena for finding other worlds by searching for planet candidates at X-ray wavelengths, a strategy that makes it possible to discover them in other galaxies,” Rosanne Di Stefano of the Harvard-Smithsonian Center for Astrophysics, lead author of the newly published study, said in a news release.
The method is similar to the one that astronomers have used for more than a decade to detect planets in our own celestial neighborhood. They keep watch on a distant star and look for slight dips in the intensity of its light. If there’s a ...