| Emission nebula | |
|---|---|
| Planetary nebula | |
 The Abell 33 nebula as seen from Mount Lemmon Observatory | |
| Observation data: J2000 epoch | |
| Right ascension | 09h 39m 09.2s |
| Declination | −02° 48′ 35″ |
| Distance | 2.7 kly (0.83 kpc) ly |
| Apparent magnitude (V) | +12.9 |
| Constellation | Hydra |
| Notable features | Foreground star gives it a "diamond ring" effect |
| Designations | PNG 238.0+34.8, PK 238+34.1, ARO 65 |
Abell 33 (Also called A33 or the Diamond ring nebula) is a faint spherical planetary nebula located 2700 light years away in the constellation of Hydra. It lies just behind the star HD 83535 which has no relation to the nebula. [1] The star HD 83535 is also responsible for the "diamond ring" effect seen in the photograph.
The nebula gets its coloration from the O III emissions (doubly ionized oxygen). The nebula is faint making it difficult to be seen using a telescope. The spherical shape of Abell 33 is mainly caused by its central star not having much of a spin. [2] The nebula shares similar morphology to another nebula with the same spherical shape, the Owl Nebula (M 97), but is much darker than the Owl Nebula. [3]
