Another redo with my new equipment.
Previous version with 12h on a CCD... this is 17h on a CMOS... same scope:
Abell 31 Sh2 290I have been working on the stars... recipe this time was the main HOO image was destarred with StarXterminator and denoised with Topaz and put back together with color help from 3D LUT. Same formula as Sh2 298. LUT used here was Saturate with Darken.
The stars were from the RGB, to get them I just denoised a stretched RGB image. I used the color denoising routine. Then saturated them a bit before adding them back to the destarred HOO with PixelMath. I was able to do photometry on them to correct the colors when stretched.
From Wikipedia:
Abell 31 is an ancient
planetary nebula in the
constellation of Cancer. It is estimated to be about 2,000
light years away. Although it is one of the largest planetary nebulae in the sky, it is not very
bright.The central star of the planetary nebula is a
white dwarf with a
spectral type of DAO.
GENERAL NOTE ON SHARPLESS2 OBJECTS>>>>>>>>>>>>>
There are 313 Sh2 objects. As of the date of this image I had imaged 313 (100%). Last in the series.
Some of the challenges with this series are FOV size and low declination:
There are 11 too diffuse/large to image well with my set up (Sh2 111, 117, 122, 131, 132, 145, 178, 218, 230, 268 and 310). I have imaged the first 6 of these mostly in the Nikon Wide angle shot referenced below and 178 and 230 as part of other images.
There are 5 that are never above 14 DEG (Sh2 2-6) but as of 7/12/21 I can get these now with pier upgrades and the images are completed as best as I can.
Many were taken with my old Tak 180 ED, which had a wide field of view, but was replaced with my Stellarvue 130, which is more narrow field. I have also taken two very wide field HA images with my Nikon D800 and a 50mm lens. I transitioned from my CCD SBIG 8300M to a CMOS ZWO ASI6200M Pro in September 2021.
The first one was taken on December 23, 2013 and the series completed October 17, 2019.This is my collection:
Sharpless2
Wide-Angle Hydrogen Alpha Nikon Image Sh2 79-171
Please note there is also a Sharpless2 Group with now more than 1500 examples.
Sharpless2 Group
Other useful links include:
Gary Imm's Collection
GalaxyMap's Collection
The Sharpless Catalog
The MDW H-alpha Sky Survey
Reiner Vogel's detailed observing catalog
Hope you enjoy these obscure but interesting objects...
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