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Young stars are surrounded by chaos: clouds of gas, dust and ice swirl around in what is known as a protoplanetary disk. And when gravity holds this material together, planets are born.
Using the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, researchers developed a new technique to measure and date young exoplanets forming in these protoplanetary disks. By studying “small whirlwinds” in protoplanetary disks visible in ALMA data, astronomers can make educated guesses about the exoplanets that caused these whirlpools to form.
Under most circumstances, scientists can use powerful telescopes to observe star dimming, which indicates an exoplanet is transiting or passing between Earth and the star. But this research team is specifically studying young exoplanets far from their stars, and these planets cannot be seen clearly using conventional techniques.
Related: Mysteries of Planet Birth Revealed in Stunning ALMA Radio Telescope Images (opens in new tab)
“It is extremely difficult to study smaller planets that are far from their star by imaging them directly: it would be like trying to spot a firefly in front of a lighthouse,” says Roman Rafikov, a professor at the university of Cambridge and the Institute for Advanced Study, said in a expression (opens in new tab). “We need other, other methods to learn about these planets.”
The team’s new technique also uses an indirect form of observation to study exoplanets: instead of looking for transits, they look for unusual formations, such as arcs or blobs, forming in the protoplanetary disk.
“Something has to be causing these structures,” Rafikov said. “One of the possible mechanisms for creating these structures – and certainly the most intriguing – is that dust particles, which we see as arcs and clumps, become concentrated at the centers of fluid vortices: essentially small cyclones that can be triggered by a specific instability in the.” Edges of gaps cut by planets in protoplanetary disks.”
By examining the properties of the vortices, which take a certain amount of time and mass to form, astronomers can estimate the age and mass of the exoplanet that created them.
“Our limitations can be combined with the limitations of other methods to improve our understanding of planetary properties and the pathways of planet formation in these systems,” Rafikov said. “By studying planet formation in other star systems, we may learn more about how our own solar system evolved.”
Two articles about the team’s research were published in the journal Monthly Notices of the Royal Astronomical Society: one about the vertebrae themselves (opens in new tab) (Dec. 20) and another above Using the vortices to measure and date exoplanets (opens in new tab) (January 4th).
Originally posted on Space.com.
