NGC 2818 & NGC 2818 A

PLANETARY NEBULA AND OPEN CLUSTER IN PIXIS (THE COMPASS)

(ra: 09h 16' 01"/ dec -36º 37')

February 2026, Home Backyard in Martinez, Buenos Aires, Argentina

DATA

TYPE: Planetary Nebula & Open Cluster

Visual Brightness: 11.6 for NGC 2818

APPARENT DIAMETER: 2 arc minutes for NGC 2818 and 7 arc minutes for NGC 2818A

DISTANCE: 10.400 light years

IMAGE INFORMATION

SCOPE: 6" ORION OPTICS UK (Ultra Grade Optics) w/Sky Watcher Coma Corrector (0.9x) working at at f4.5

CAMERA: QHY 183 MONO

MOUNT: SKYWATCHER NEQ6, OAG with QHY 5II Mono

FILTERS:  OPTOLONG LRGB Set

SKY CONDITIONS: Urban Skies. Bortle 9

EXPOSURES: LRGB (45,45,45,45) - all channels bin 1x1

OBJECT DESCRIPTION AND IMAGE SESSION

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,  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.

NGC 2818 appears very close to the open star cluster NGC 2818 A. Whether it is a member of the open cluster has been controversial: earlier papers found the radial velocity differences between the planetary nebula and open cluster to a chance alignment. However, more recent studies suggest that NGC 2818 is indeed a member of NGC 2818A