Throwing off gas in concentric shells, the Cat’s Eye Nebula above is one of the most complex and interesting known planetary phase nebulae and is located about three thousand light years from Earth in the Draco constellation. This image, captured by the Hubble Space Telescope in 2004, has led scientists to believe the complicated and intricate structures on display may be the cause of a binary star system in the centre of the nebula because of the unique shell formation.
In astronomical terms the nebula is very young at only about a thousand years old, forming after a sudden change in mass of the central star (or stars). The reasons for this change in mass is still unknown, but the lighter rings of gas around the edges are known to have been produced in bursts in the latter stages of stellar evolution before the inner nebula formed. Observations over the past 20 years indicate the nebula is still expanding, and continued measurements will allow astronomers to see how a young nebula like this changes its shape and characteristics as it grows.
Image courtesy of NASA.