NGC6910
NGC6910 - Click here for full resolution
NGC 6910 is an open cluster in the constellation Cygnus. It was discovered by William Herschel on October 17, 1786. The cluster was also observed by John Herschel on September 18, 1828. NGC 6910 is located half a degree east-north east of Gamma Cygni, also known as Sadr. The Sadr Region is rich of emission and dark nebulae. Other examples are the Gamma Cygni nebula (IC1318) and the Crescent Nebula (NGC6888).
source: Wikipedia
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NGC6910
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Open Cluster
Cygnus
20h 23m 12s
+40° 46.6′
29 Aug
87º N
Conditions
NGC6910 is a better target for late summer, early autumn, with peak altitudes of 87° in late August. But also in June it reached decent altitudes towards the second half of the night from the remote observatory at IC Astronomy in Oria, Spain. As such it was a good target to image during the full moon period of June. Images were taken over 12 nights between mid early to late June 2024.
Equipment
The default rig at the observatory was used. This is built around a Planewave CDK-14 telescope on a 10Micron GM2000 mount, coupled to a Moravian C3-61000 Pro full-frame camera. The RoboTarget module in Voyager Advanced automated the process to find optimal time-slots during astronomical night.
Telescope
Mount
Camera
Filters
Guiding
Accessoires
Software
Planewave CDK14, Optec Gemini Rotating focuser
10Micron GM2000HPS, custom pier
Moravian C3-61000 Pro, cooled to -10 ºC
Chroma 2” H-alpha, SII, OIII (all 3nm) and Red, Green and Blue unmounted, Moravian filterwheel L, 7-position
Unguided
Compulab Tensor I-22, Windows 11, Dragonfly, Pegasus Ultimate Powerbox v2
Voyager Advanced, Viking, Mountwizzard4, Astroplanner, PixInsight 1.8.9-3
Imaging
The Sadr Region is often photographed in broadband. Also the fact that NGC6910 is a star cluster suggests that broadband is a good option to image. But it is located in an area full of exciting emission nebulae, dark nebulae etc, making it a nice narrowband target as well. For this image, the narrowband option was chosen and processed using the SHO Hubble palette. Separate RGB images were taken to give the stars their most natural colour. Narrowband Images were shot using 10 min exposures each, broadband images were limited to 3 min exposure each. A total of almost 32 hours of data was acquired.
Resolution (original)
Focal length
Pixel size
Resolution
Field of View (original)
Image center
9576 × 6388 px (61 MP)
2585 mm @ f/7.3
3.8 µm
0.30 arcsec/px
48' x 32'
RA: 20h 22m 55.208s
Dec: +40° 48’ 33.45”
Processing
All images were calibrated using Darks (50), Flats (25) and Flat-Darks, registered and integrated using the FastBatchPreProcessing (FBPP) script in PixInsight. The processing was kept very similar to the processing of Sh2-112.
Gradients were removed per channel using GraXpert, then combined into the Hubble palette (SHO). SPCC, BlurXTerminator and StarXTerminator led to an unstretched starless SHO image. The Unlinked Stretching Bill Blanshan script was used for the first stretch, enough to run NarrowbandNormalization to get the colours right. Some of the big stars had left a bit of a magenta ‘ghost’ during the removal of the stars. This was removed using SCNR on an inverted version. Noise was reduced and final stretching was completed with some targeted runs of GHS and HistogramTransformation. To make the blue pop a bit more, a small s-curve on the CIE b* component in CurvesTransformation was applied wile protecting the rest of the image with a blue mask. As a final touch a little sharpening and further noise reduction was applied.
In the broadband images for the stars, gradients were first individually removed before putting together the RGB image. SPCC and BXT resulted in nice sharp and properly coloured stars. They were removed using SXT and stretched to a non-linear version using the StarStretch script from SetiAstro.
Stars and SHO image were combined using PixelMath. A final mild noise reduction led to the final image.
Processing workflow (click to enlarge)
This image has been published on Astrobin and received Top Pick nomination status.
