Scientists have found this nebula to exhibit a double-ring structure that evidences not one, but possibly three stars at its ...

The Ring Nebula is perhaps one of the most photographed objects in the night sky, dating back to its first image in 1886. Its intrinsic structure has been debated for as long as it has been observed.

In addition to helping the researchers nail down the nebula's ellipsoidal structure, the 3D model also ... orbits the central white dwarf. That hidden star, which astronomers estimate should ...