Abell 74 Large, Dim Planetary Nebula in HOO (Vulpecula) - July, 2023
Planewave CDK12.5; AP 1100GTO AE
ASI6200MM, - Antlia Pro RGB & 3.5nm NB filters
Ha,OIII: (46,31 x 600s exposures, Bin 2x2, Gain 200)
R,G,B: (20,16,22 x 120s, Bin 2x2, Gain 200)
Total Integration Time = 14.8 hours
As far as Planetary Nebulae go, Abell 74 is ancient. This makes it both very large (4 ly radius) as it has had a long time to expand, but extremely dim as its central white dwarf cools and the nebular gases thin. For comparison, the Ring Nebula is only 1.3 ly radius. In addition, it is not as structurally defined as many other planetary nebulae, as the gases take their random walk of diffusion and dispersion. Abell 74 is 1800 to 2500 light years away depending on the source – about the same distance as the Ring Nebula.
Initially, one would think that the central moderately bright star neary in the middle of the PN. However, I believe it to actually be the very blue, much smaller star slightly towards the bottom left (at 4:30 from the brighter star).
This image was a challenge both to image and process – due to both it being dim, and its composition – consisting of stars, nebulosity and galaxies that can be seen both through and outside the nebulosity.