Urban Squid Nebula

Here is another urban image taken from my driveway . This shot was taken with a gibbous Moon in the sky and lots of urban light pollution.

This one definitely qualifies as DIM! My planned eight hour exposure was cut very short by having the target move behind a tree in my front yard so I will have to add more subs as time and weather allow. In order to bring out the Squid I used some of the same techniques I used to bring out the star stream surrounding
NGC5907. Some very laborious mask building with a lot of blurring and contrast enhancing was used to make the Squid visible in the mask. The mask was then applied to several of the initial stretches to make the nebula visible.

The Squid (Ou4) is a faint reflection nebula at the core of the Flying Bat Nebula (I have no idea how it got that name) SH2-129 in Cepheus. Once considered a challenge object to image, modern equipment and filters make the data relatively easy to capture as can be seen in the slightly over two hour exposure below. The real challenge is to tease out the very faint details while processing the data. This image needs about 6 to 8 hours of data to maintain crisp detail and muxh of it was lost in this attempt as there is substantial noise reduction applied due to the short exposure. Check back often as I'll add some data every clear night as long as the object is not behind trees.

Click on the image to see a higher resolution version, then click again on the image to return to this page.


Object M5  Object RA 15:18:37, Dec+2:04:59
Date 3 Dec, 2020
Exposure 2 hours 15 minutes (9 X 15 minutes)
Conditions Bortle 7 to 8 skies, high light pollution levels and a bright Moon.
Gain 100
Camera Zwo ASI2600MC-Pro
Optics Prime focus of a  SkyWatcher Esprit 120 f/7 APO refractor with a focal length of 840 mm
Filter Optolong L-eNhance
Location Bedford, Nova Scotia
Processing This image was captured using Sequence Generator Pro, telescope control provided by Mosaic Engine and processed entirely in Images Plus.  Masked arcsinh stretch,  masked noise reduction and saturation boost used to make the nebula more pronounced after the feature mask was used to remove the stars. Multi-scale decomposition used with the merge split blend mode to further enhance the faint nebulosity.  Multi-point flatten used to remove gradient and balance the background. Stars recombined with the nebula image and the result binned to reduce the image size for web display.