Standard minimalist processing.

Here are some details on the processing as I am in production trying to finish the series.

On the RGB, I have learned that I just need the R & B images and to make a synthetic G from the average of the R&B (they are two ends of the spectrum).  The Photometric calibration of these these in Pixinsight produces the correct stars colors anyhow.  This also maximized the number of stars since seems the G is mostly noise (there are few green stars). 

On the HA this is usually strong and the only gain from multiple long exposures is noise reduction, but with Topaz you can get rid of that by reducing noise on the destarred HA.  This is then stretched, and the stars are put back from a grey scale version of the RGB stars... I reduce the intensity to 70% to now blow out the colors when the HA is added to the Red... that is a multistep process but is well known. 

From GalaxyMap:

Sh 2-40 appears as several bright knots of nebulosity extending above the much larger nebula Sh 2-41[color=#ffffff].[/color]

Avedisova suggests that Sh 2-40 is ionised by the B-class star LSS 4756[color=#ffffff].[/color]

The RCW catalog lists the bit of Sh 2-40 that is furthest from the galactic plane as RCW 155a and the brighter bits closer to the galactic plane as RCW 155b.

GENERAL NOTE ON SHARPLESS2 OBJECTS>>>>>>>>>>>>>

There are 313 Sh2 objects.  As of the date of this image I had imaged 300 (96%).

Here is the scorecard:

There are 12 too diffuse/large to image well with my set up (Sh2 111, 117, 122, 131, 132, 145, 178, 218, 221, 230, 268 and 310).  I have images the first 6 of these mostly in the Nikon Wide angle shot referenced below and 178 and 230 as part of other images.  I will do the rest at least once as they come into view this year, so I have 4 more of these to do.  I missed 303 and 304 last year running out of time.  So there are 6 more to do here.

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.  There are still 7 low ones between Sh2 30-50 that I can do this summer.

These 13 remaining all are in Expert Scheduler waiting for them to pass by.

The first one was taken on December 23, 2013.

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.

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...