Abell 33 Diamond Ring nebula

A planetary nebula in the constellation of Hydra situated at a distance of 828 parsecs (2700 ly). The star HD 83535 at 216 parsecs has given this PN more prominence by creating a line of sight optical illusion of a diamond ring as viewed from our solar system. At the centre of the PN is a double star, most likely an optical double and not a binary system.

According to the wonderful Deep Sky Compendium Companion by Gary Imm (*) about 10% of Planetary Nebulae (PNe) are spherical like here in Abell 33. He further explains that if the central progenitor star was a binary system then the PN would more likely either be a Bipolar or Elliptical PN, supporting the idea that this is an optical double.

In the RGB star image there appears to be a slight hint of a yellowish coloured star below a blue star, but far from being conclusive. There is on Astrobin however an image taken using a 1 metre scope that confirms that, an IOTD in 2022.

(*) If you have a few spare days then I'd recommend downloading and browsing Gary Imm's amazing compendium from his site. The effort he has put into it is incredible.