“In most studies, the nebula usually gets bigger. Here, it’s fundamentally changing its shape and getting fainter, and doing so on an unprecedented time scale.
“Moreover, to our surprise, it’s not growing any larger. Indeed, the once-bright inner elliptical ring seems to be shrinking as it fades.”
Although Earth-based observations of other planetary nebulae have hinted at evolving brightness, such speculations have only now been confirmed.
Dr Guerrero added only the orbital Hubble is up to the task of resolving the changes in structure in such a small nebula.