Sadr region (100h / 9 panels mosaic)

Image Title: Sadr region (100h / 9 panels mosaic)

Date image was taken: August 20, 2023

Location: Corsica (France)

Image Description and Details: I am delighted to share with you this image, which has been my main project for the summer of 2022 (with a few additions in the summer of 2023): it's a mosaic of 9 images in the Sadr region, in the constellation of Cygnus, made with a Takahashi TSA-102 (f:600mm) and an Atik 16200 mono camera.

It includes well-known objects often imaged separately: the Butterfly Nebula, the Crescent Nebula (NGC 6888), the Helix Nebula (Simeis 57), the reflection region of NGC 6914...

This image represents a total of 100 hours of SHO exposure, supplemented by shorter RGB series for star color.

Acquisitions were spread over some twenty nights, mainly in Corsica.

Processing was particularly time-consuming and complex, especially for assembling and harmonizing the different tiles (a few bugs on APP with duplicate stars in certain overlapping areas, which forced me to finalize the assembly with Pixinsight).

SHO processing with a mix of Ha and SII layers for luminance, with a localized complement for the OIII layer.

For the colors, there was a huge choice; I opted for a fairly warm SHO palette, with some specific treatments for certain objects:

- HOO version for the crescent, which otherwise came out exclusively blue (with a loss of detail in the process), and for the small bubble nearby;

- SHO version modified for Simeis 57 ;

- mixed LRGB/Ha version for the NGC 6914 region.

For these localized treatments, I also used images of these objects taken previously.

The stars were processed in RGB (with the Ha layer as luminance).

Processing was carried out entirely on a 2x drizzle version of the image, and reduced to 50% in the end.

Given the very large size of the image, the version published here is very reduced (~25%) ; but the full version is available here : https://astrob.in/d2pmdp/D/

Many small planetary nebulae are visible on the image : Ju1, Dd1, DSH J2009.6+4114 & G075.6+04.3... can you find them on the full version ? :)

JB

Equipment Details: Takahashi TSA-102 (f/6 - 600mm focal)

AZEQ6

Atik Cameras 16200 MM

Filters : Baader SHO ultra-narrowband + RGB

Ha : 182 x 900s (45h30)

OIII : 144 x 600s (24h)

SII : 144 x 600s (24h)

RGB : 420 x 60s

Total : 100h30

20 nights (06/08/2022 to 26/08/2022 & 20/08/2023)

Copyright: Jean-Baptiste Auroux

Website or Facebook Profile: https://millenniumphoton.com/