Rare Discovery: Scientists Found Oldest Planetary Disk In Unusual Location

Planetary disks have been spotted before, but never around a very old red dwarf star. A group of citizen scientists and professional astronomers from Disk Detective, a project led by NASA/GSFC's Dr. Marc Kuchner discovered the oldest known planetary disk in an unusual ground.

The group was formed in an attempt to find possible planet-forming regions. As noted by Phys.org, planetary disks around red dwarfs are rare because these disks are often associated with young planetary systems.

The star called AWI0005x3s, appears to have sustained its disk for an exceptionally long time --- at 45 million years to be exact. Steven Silverberg of University of Oklahoma said that most disks of this kind usually fade away in less than 30 million years.

Circumstellar disk is a primordial ring of gas, dust, or collision fragments in orbit around a star. A dissertation published in Harvard University said circumstellar disks provide the reservoirs of raw material and initial physical conditions for the formation of nascent planetary systems which is important in studying the planet formation process.

"It is surprising to see a circumstellar disk around a star that may be 45 million years old, because we normally expect these disks to dissipate within a few million years," Carnegie's Jonathan Gagné, who was involved in the study explained in a press release.

"More observations will be needed to determine whether the star is really as old as we suspect, and if it turns out to be, it will certainly become a benchmark system to understand the lifetime of disks."

Aside from the planetary disk unusually lasting for a long time, the discovery is also interesting because of the chance that it could host extrasolar planets.

"Without the help of the citizen scientists examining these objects and finding the good ones, we might never have spotted this object," Kuchner said. "The WISE mission alone found 747 million [warm infrared] objects, of which we expect a few thousand to be circumstellar disks."

The discovery was detailed in a new paper, published this week in the Astrophysical Journal Letters.