AstroDMx Capture was used with an SV605CC OSC colour CMOS camera and an Altair Starwave ASCENT 60ED doublet refractor with 0.8 reducer/flattener and a Pegasus Focuscube v2. An Altair 2” magnetic filter holder version 2 containing an Altair quadband filter was placed in the optical train.
The equipment was mounted on a Celestron AVX GOTO mount. An SVBONY SV165 guide-scope fitted with a QHY-5II-M guide camera was mounted on the imaging scope. An INDI server was running on the imaging Linux computer indoors. The guide camera was connected by USB to another Linux computer indoors running PHD2 autoguiding software via the INDI server. The mount and the focuser were controlled by AstroDMx Capture via the INDI server.
AstroDMx Capture slewed the scope to the star Altair and plate-solved to centre it. A Bahtinov mask was used to enable Altair to be brought into sharp focus.
Screenshot of PHD2 autoguiding
Then AstroDMx Capture plate-solved and sent the scope to the star HD 240247. This star was chosen so that the image would frame a region containing five objects: SH2-157, the Lobster claw nebula, NGC 7635, the Bubble nebula, NGC 7538 (emission nebula), NGC 7510 and M52 (open clusters).
AstroDMx Capture was used to capture 26 x 5-minute RAW exposures of the region.
Screenshot of AstroDMx Capture saving RAW FITS files. Live stacking was used to improve the preview of the captured image.
Negative preview
26 light frames, 5 dark frames, 50 bias frames, 50 flatfields and 50 dark flats. To capture the flats and other calibration frames, the scope was slewed to ther zenith and tracking stopped. The flats were captured using a device designed to avoid lateral light leakage and using a stack of 3mm thick acrylic white A5 sheets to evenly diffuse the light from a light panel and attenuate it sufficiently to get Flats of 1.5s duration.
The Flat field equipment
The data were calibrated, debayered, stacked and part processed in PixInsight and completed in GraXpert, Seti Astro Suite Pro Cosmic Clarity and Gimp. A Pixinsight Cosmic Photons script was used to Generate a Hertzprung Russel diagram of the stars in the image.
Hertzprung Russel diagram of the stars in the stacked image
The Lobster claw nebula region. All images with RGB stars.
RGB channels linked
