NGC 2818
| Emission nebula | |
|---|---|
| Planetary nebula | |
Hubble Space Telescope image of NGC 2818 (red: nitrogen, green: hydrogen, blue: oxygen) | |
| Observation data: J2000.0 epoch | |
| Right ascension | 09h 16m 01.656s |
| Declination | −36° 37′ 38.76″ |
| Distance | 10,400 ly |
| Apparent dimensions (V) | 2' |
| Constellation | Pyxis |
| Physical characteristics | |
| Radius | 3.25 ly |
| Designations | NGC 2818, PLN 261+8.1 ESO 372-PN13 |
NGC 2818 is a planetary nebula located in the southern constellation Pyxis (The Compass). It consists largely of glowing gases from the star's outer layers ejected during the final stages of its life when it had run out of the fuel necessary to sustain its core fusion processes. The remnants of its core will remain as a white dwarf.
NGC 2818 presents a complex morphology, and overall has bipolar structure, making it a bipolar nebula. The two lobes are somewhat broken and irregular. There are also filamentary structures radiating from the center, and near the center of the nebula, several cometary knots. The mass of the nebula is estimated at 0.6 solar masses. It is about 11,000 years old.
The progenitor star was likely about 2.3 times the mass of the Sun. The central star is very hot, with an effective temperature of 130 kK.