Using a new method to measure the change in X-rays emitted from a distant star, astronomers may have for the first time located a planet orbiting a star in a neighboring galaxy, NBC News reports.
The planet is in the galaxy designated Messier 51, or M51, known as the Whirlpool Galaxy. It orbits a binary star system, in which one of the stars is a neutron star or black hole, so instead of emitting visible light, it gives off X-rays. Earth-bound astronomers leverage a process called transiting–when a planet passing between the sun and the observers, slightly dimming the sun's glow–to identify the location, orbit and size of interstellar planets.
In this case, they adopted the transiting technique to measure the drop in X-rays coming from the binary star system to locate the planet. The drop was repeated over a periodic time frame, showing the existence of a body orbiting the stars.
"The awesome thing is that they found a planet orbiting around a neutron star that is part of a system that has been through a supernova explosion and had an interesting and complicated evolutionary history," he said. "It's exciting that a planet can survive having its star blow up."