Caldwell 27 – The Crescent Nebula


Matt Foyle


NEQ6 Pro
Baader 2″ filters
Guided with Orion miniguider and QHY5M camera through the guideport
Processed in Nebulosity V3 and Photoshop

Caldwell 27 or NGC6888 the Crescent Nebula

Taken over three nights 03-06-13, 06-06-13 & 07-06-2013

Ha = 12 x 1200s
LRGB = 5 x 600s
Total time = 7hrs 20min

Taken over three nights with only a few hours of darkness each night in less than ideal seeing conditions.

This image is still slightly over processed as it was far from crystal clear. On the 7th at around 2am, while collecting the last of the Hydrogen Alpha Data I couldn’t see any stars and had bright orange clouds in the east as the sun was rising very fast indeed.

I had set myself the challenge of getting this target over two short sessions due to the inclement weather forecast and the rather short available hours of darkness. The first night went rather badly as I took 3x 20mins Ha exposures that were out of focus so I lost a big portion of that night. The second night was mostly spent on the LRGB data and still proved tricky due to the high haze. The third night was incredibly cloudy but I had already decided it was a extra unforecast night so went for topping up the Ha on the longer 20min exposures.

Overall this image is more processed than I would of liked but that is in part due to the fact the data wasn’t taken on crystal clear nights. The Soap Bubble Planetary nebula is in the top of the frame at about the 11 O’Clock position from the Crescent Nebula. This data is lacking on OIII data but given the schedule and poor weather at present, I’m more than happy to go back to this target in the future.