The colors in these images are due to imaging with filters optimized for wavelengths of Nitrogen, Oxygen, and Helium. The angular size of this PNe is 16 arcseconds. It is estimated to be 3,500 light years distant. The distance to this planetary is estimated to be 2,600 light-years. All the images in this panel were taken by Dr. Bruce Balick using the 2.1 meter telescope at the Kitt Peak National Obs.
Hydra is classified as a 'ring' nebula.
A more well known ring nebula is known as 'M57' in the constellation Lyra. The distance to M57 is about 2,000 ly and the distance to NGC2610 is 5,500 ly.