The Rosette Nebula from Bortle 8 LPLondon

Here is a photograph of the night skies taken over three nights of the full moon at the end of March.  This is NGC2237, the Rosette Nebula.

This was a tough image to capture.  At this time of year, the nebula is only visible from my back garden for about 1.5 hours on each day of imaging, before it sinks below the horizon.  To make things even more difficult, there was wispy high cloud cover on two of the three nights, as well as the full moon.

I have imaged this object before, with my previous camera, so I wanted to make a comparison with my new Altair 26M and it’s Sony IMX571 APS-C sized sensor.  Since I only managed to achieve less than a quarter of the exposure, I wasn’t expecting much — but to be frank I am blown away as to how sensitvie my new camera is.  I have significantly more signal in a total of four hours than with my old ZWO ASI1600MM with the same setup on the same target in 16 hours!

For those who are interested in such things, I’ve added an overview collage of the raw emission channels, so that you can see for yourselves how they are composed into a final colour image.  Bottom left of the collage is Sulphur II, mapped to red; top right is Hydrogen Alpha, mapped to green; bottom right is Oxygen III, mapped to blue.

Taken from Light Polluted London (bortle class 8).

Total of 4 hours of exposure:
• 16 x 300s Ha
• 16 x 300s Oiii
• 16 x 300s Sii

Hardware:
• Altair 26M Pro TEC Camera
• Vixen AX103S Telescope
• Vixen 0.7x Flattener for AX103S
• Pegasus Falcon Rotator
• ZWO EFW3 Filter Wheel
• Antlia 36mm 3.5nm SHO Filters
• DeepSkyDad AF3 Autofocuser
• SkyWatcher HEQ5 Mount
• SkyWatcher Evoguide Guide Scope
• Altair 290M Guide Camera

Software:
• N.I.N.A. -- Capturing
• PHD2 -- Guiding
• ASTAP -- Plate Solving
• EzSuite — LiveStacking and Calibration
• PixInsight — Stacking and Processing
• Affinity Photo — Collage and Tweaks