The article notes, "Moreover, AS 209's disk has a relatively small mass, and appears to be stable at the moment based on its gas surface density profile and its temperature in the midplane. "While it is not impossible that the disk was sufficiently massive in the past, the small present-day disk mass implies that the disk should have lost its mass very efficiently since then," the researchers wrote in their paper (opens in new tab), published in Astrophysical Journal Letters July 27."
The paper,
https://arxiv.org/abs/2207.05923
The abstract and PDF paper (19-pages) indicate the mass in some places like the CPD (circumplanetary disk) would be near 30 earth masses and dust about 2.2 lunar mass. The paper shows perhaps a total dust mass of 300 earth masses in the disc. AS 209 is a 1.2 solar mass star and applying the MMSN to 1.2 solar mass star yields close to 4,000 earth masses for a total disc. AS 209 is said to be some 1-2 Myr old. Other sourcers indicate the disc diameter is near 278 AU size,
Catalog of Circumstellar Disks
AS 209 exoplanet(s) interpreted remain to be verified. What this report does indicate, solar mass stars like our Sun or AS 209, exhibit a wide range of possible disc sizes and masses, when they can be resolved and studied.