These so-called protoplanetary disks, which are the birthplaces of young planets, are of interest to scientists because they offer glimpses into what the solar system may have looked like in its infancy and into how planets may form in general. Scientists have long thought that spiral arms in these disks could be caused by nascent planets, yet none had been detected until now.

In a paper published in Nature Astronomy, University of Arizona researchers report the discovery of a giant exoplanet, dubbed MWC 758c, that may be generating the spiral arms in its infant planetary system. The astronomers also propose possibilities as to why scientists have struggled to find this planet in the past, as well as how their methods may apply to detecting other concealed planets in similar circumstances.

"Our study puts forward a solid piece of evidence that these spiral arms are caused by giant planets," said Kevin Wagner, lead author of the paper and a postdoctoral researcher at the University of Arizona Steward Observatory. "And with the new James Webb Space Telescope, we will be able to further test and support this idea by searching for more planets like MWC 758c."

The planet's star is located about 500 light-years away from Earth and is only a few million years old—an embryo compared to our own 4.6-billion-year-old sun. Hence, the system still has a protoplanetary disk, as it takes about 10 million years for the circling debris to either be ejected out of the system, ingested by the star, or formed into planets, moons, asteroids and comets. The prominent spiral pattern in this system's debris was first discovered in 2013, and astronomers were quick to point out the connection to theoretical simulations of forming giant planets.