This is my list of CCD imaged Sharpless HII regions. The Sharpless catalogue is ordered by right ascension and starts in the southern milkway, a lot of objects I can hardly reach from here. Scroll down beyond these and you'll see thumbnails next to the Sharpless objects that I've managed to image using Astrodon narrowband filters and ATIK CCD cameras.
The Sharpless Catalog contains some 313 entries, mostly partially ionized H II regions. Many of them a simple star forming regions, but with a sprinkling of supernova remnants, planetary nebulae and other classes. Most can be imaged using narrowband filters - primarily a Hydrogen Alpha filter (Ha). All my narrowband CCD Images are taken with Astrodon Narrowband filters.
The catalog was constructed by Stewart Sharpless in the 1950s using the plates from he Palomar Sky Survey. The entries in the Sharpless catalogue range from the bright and familiar, such as the Orion Nebula (Sharpless Sh2-281) to the very dim such as the barely detectable Sh2-169. There are also a few that have no right to be there e.g. Sharpless 191 is actually a galaxy!
A note on numbering: The first edition of the Sharpless Catalog came out in 1953 and contains 142 objects. These are often labelled without the addition of the 2 numeral. e.g. Sh-12, Sh-100. The expanded second edition contained 312 entries, and these usually are listed as Sh2-281 etc. The first 142 Sharpless objects are the same in each edition, so there is nothing wrong with using the labell Sh2-100 for the lower numbers. That said, some people ignore the edition and just list everything with Sh, e.g. Sh-218 which is technically incorrect. I have adopted the policy of listing everything with the numeral 2. Sometimes. :)
So far we have images of 123 Sharpless Catalogue objects as of 19 August 2018.
Imaging the entire catalogue from my location, 51N, is not possible - some
are below the horizon or barely scraping above it. The record is 19.5 degress
south declination. 39 Sharpless objects lie south of this, and are probably
unreachable.
Form: 1=circular; 2=elliptical; 3=irregular
Structure: From 1=amorphous to 3=filamentary
Brightness: From 1=faintest to 3=brightest
Stars:Number of associated stars in the HII region
