The Coal Sack Loop: a 0.7 Giga pixel mosaic with 200 hours of exposure! (Rainer Raupach)

The Coal Sack Loop: a 0.7 Giga pixel mosaic with 200 hours of exposure!

Link: http://www.capella-observatory.com/ImageHTMLs/StarFields/CoalSackGiga.htm

The first major project of our remote observatory in Namibia is complete. This gigantic 4x4 full-frame mosaic in SHO was created over a period of approximately two months of exposure and covers an area of about 15° x 11° with 1.78" resolution (for comparison, the full moon is shown to scale in the upper left corner of the preview here). Each panel contains 12.5 hours of exposure time (5 hours each for SII and OIII, and 2.5 hours for Ha), resulting in a total of 200 hours of photons for the entire image.

The 100% view on AstroBin had to be reduced to ~264 Mega pixels due to technical requirements. The original full resolution can only be assessed on the Capella web site: http://www.capella-observatory.com/ImageHTMLs/StarFields/CoalSackGiga.htm

The lights alone take up about 300 GB on the hard drive. Due to the huge amount of data and the final image size, the processing was also quite challenging. You can probably imagine that such an image pushes many computers to their limits. Additionally, achieving consistent calibration across all panels is a difficulty to be solved in order to obtain a homogeneous mosaic later on.From the SHO data, we have generated two different versions: a classic Hubble palette and a bicolor version that approximates the actual optical appearance. The real fun comes when viewing it with the viewer on the Capella website, which allows dynamic zooming and switching between versions (with optional annotations as well).

The mosaic shows the complete field around the coal sack, including the entire Southern Cross. Clearly visible in the overview here in the post as the Hubble palette is the massive Ha loop in the field. At higher zoom levels, numerous small objects become visible (planetary nebulae, emission nebulae, supernova remnants, and even a number of background galaxies). To examine the details, the website is suitable (preferably a version with annotations as a guide). Below the large display of the mosaic on the Capella website, you can find some interesting objects as crops. By clicking on them, you can bring the large mosaic to that position. Additionally, there is more information about the capture and technique available there.

Enjoy this unusual image,
Rainer Raupach, Josef Pöpsel, and Frank Sackenheim
(Capella Observatory South: http://www.capella-observatory.com/)

Original
Final
B

B

Description: Bicolor version

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Status	Advanced success
Started	...
Astrometry.net job	8429812
PixInsight job	8HSSMQGH7FMVL1TTHNDNK373IWLZAY7A
PixInsight queue size	n/a
PixInsight stage	TASK_LOG

RA (center)	13h03m15s.34
RA (top/left)	13h54m30s.50
RA (top/right)	12h06m09s.56
RA (bottom/right)	11h48m54s.58
RA (bottom/left)	14h20m02s.24

Dec (center)	-61°41′12″.7
Dec (top/left)	-55°09′18″.7
Dec (top/right)	-55°49′08″.5
Dec (bottom/right)	-66°28′02″.4
Dec (bottom/left)	-65°26′20″.2

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