Abell 36 — A Planetary Nebula in Virgo
RA/Dec (J2000): ~ 13h 40m 41s, −19° 52′ 57″ (DeepSky Corner)
Historical Overview
- Abell 36 was discovered in 1955 by George O. Abell during his search of the Palomar Observatory Sky Survey plates for faint planetary nebulae. (DeepSky Corner)
- It appears in Abell’s original catalogues of “old planetary nebulae” (1955) and in his follow-up work (1966) refining physical data. (Wikipedia)
Physical & Observational Properties
| Property | Value / Description |
| Distance: | ~ 780 light-years (~240 parsecs) from Earth. (Waid Observatory) |
| Age: | Estimated at ~10,000 years since the nebula was ejected. (DeepSky Corner) |
| Morphology: | Very faint, barrel-shaped halo of Hα-ionized gas, with inner structure that shows bipolar lobes; barrel or elongated shell. Similar in some respects to the Cat’s Eye Nebula’s inner structure. (DeepSky Corner) |
| Angular size: | The halo has an angular diameter of ~4° × 5° in deep exposures. The brighter optical shell is much smaller: around 6′ across. (DeepSky Corner) |
| Central Star Temperature: | Over ~73,000 K. (Waid Observatory) |
| Radial / Expansion Velocity: | The expansion velocity (from [O III] lines) is ~36 km/s. Radial velocity ~ +36.8 ± 3.3 km/s. (DeepSky Corner) |
| Central star magnitude: | The central star ~11.5 mag. (Stellar Scenes) |
Key Facts & Significance
- Abell 36 is one of the closest planetary nebulae (∼780 ly), which makes it valuable for detailed study of old, large, faint PNe. (Waid Observatory)
- Its large, very low surface brightness halo shows complex structure, indicating that it is in a relatively advanced evolutionary stage, where outer shells are dissipating into the interstellar medium. (DeepSky Corner)
- Because of its proximity and the clarity of its inner shell and central star, it’s often used in studies of planetary nebula morphology, expansion dynamics, and the transition of stars to the white dwarf stage. (ResearchGate)
References
Waid-Observatory imaging and data summary (Waid Observatory)
Abell, G. O. (1955). “Globular Clusters and Planetary Nebulae Discovered on the National Geographic Society-Palomar Observatory Sky Survey.” PASP, 67, 258. (DeepSky Corner)
Abell, G. O. (1966). “Properties of Some Old Planetary Nebulae.” Astrophysical Journal, 144, 259. (Wikipedia)
DeepSkyCorner: “Planetary Nebula Abell 36” entry (DeepSky Corner)
Cropped image as the nebula is small with angular size of about 7.5 arc minutes x 5 arc minutes