Scientists find oldest-known planetary disk

Washington, Oct 22: Astronomers believe they have found the oldest known planet-forming disk — a 45-million-year-old ring of gas and dust that orbits around a young star. Circumstellar disks around red dwarfs like this one are rare to begin with, but this star, called AWI0005x3s, appears to have sustained its disk for an exceptiolly long time. “Most disks of this kind fade away in less than 30 million years,” said lead researcher Steven Silverberg from University of Oklahoma in the US. “This particular red dwarf is a candidate member of the Cari stellar association, which would make it around 45 million years old (like the rest of the stars in that group). It’s the oldest red dwarf system with a disk we’ve seen in one of these associations,” Silverberg noted. The discovery relied on citizen scientists from Disk Detective, a project led by SA’s Goddard Space Flight Center’s Marc Kuchner that is designed to find new circumstellar disks. “Without the help of the citizen scientists examining these objects and finding the good ones, we might never have spotted this object,” Kuchner said. (IANS)