Abell 33 (also PNG 238.0+34.8, PK 238+34.1, 2MASS J09390908-0248319 and ARO 65) is a magnitude +13.4 round planetary nebula located 2,500 light-years away in the constellation of Hydra. It lies very close to a foreground magnitude +7.0 star HD 83535. The star HD 83535 is responsible for the "diamond ring" effect.
The planetary nebula was discovered by American astronomer George Ogden Abell at the Palomar Observatory in 1955
Right ascension09h 39m 09.2s, Declination-02° 48' 35"