Helix nebula(redirected from NGC 7293)
Helix nebula(hee -liks) (NGC 7293) A planetary nebula lying in the southern hemisphere about 140 parsecs away in the direction of Aquarius. It has the largest apparent diameter (0°.2) of any planetary nebula but at magnitude 6.5 is too faint to be seen with the naked eye.
Helix Nebula[′hē‚liks ′neb·yə·lə]
A planetary nebula in Aquarius about 140 parsecs (2.7 × 1015 miles or 4.3 × 1015 kilometers) distant that has a high helium abundance and the largest known diameter of any planetary nebula.