Researchers from the Herschel Space Observatory (HSO) have discovered a mysterious ring of dusty material while taking some of the sharpest images of pre-star dust and gas formations to date.

The HSO - a European Space Agency mission with NASA contributions - was used to identified 13 massive and dense clouds of gas and dust that may one day become colossal stars - the most powerful kinds of stars in the known universe.

"In addition, we have found a gigantic ring structure and the weird thing is, we're not at all sure what created it," lead investigator Cassandra Fallscheer, of Whitman College in Walla Walla, Washington, said in a recent statement.

According to these findings, unlike the surrounding pre-star cloud it is found in, the mysterious dusty ring presents itself as cool, with an oval-like shape 35 light-years long and 25 light-years wide. The researchers who discovered it suspect that the ring has a mass about 500 times that of the Sun.

"Astronomers often see ring and bubble-like structures in cosmic dust clouds," according to the HSO.

These structures are formed when strong cosmic winds generated by massive O-type stars literally blow the cloud around, cooling portions of it and creating a bubble or ring.

However, "no energetic source or remnant of a deceased O-type star, such as a neutron star, is apparent within the center of the ring," the observatory reports.

According to Fallscheer, it's possible that a fast-moving O-type had been at the "cosmic nursery" identified as NGC 7538 briefly, but - as stars are constantly in motion - had since left the scene, escaping detection.

There are other ways researchers can determine the actual original of this mysterious ring, but Fallscheer said it will take a bit more sleuthing.

Fallscher and her team reported their findings in a paper published in The Astrophysical Journal.