The North America Nebula

The North America Nebula region. Click to see the 100% crop of the final stacked image. This area spans about 3x2 degrees of the sky.

"First light" in my new observatory. The mount was poorly polar aligned - about 1 degree off. Inspired by Mark-Jaap ten Hove's idea 1), deepsky section, image of M31 27-08-2014 using 30s subs of using very small sub-times, I decided to give the North America Nebula a try, before it will disappear from the winter skies. The result is striking. In the course of about 4 hours, the field drifted about 2 degrees, so only half of all images overlapped. The conditions were relatively good, with NELM 6.0 in zenith, but with fog drifting in later in the night. After I started the imaging sequence at about 22:00, I went to bed, and turned the rig off after waking up in the morning before heading off to work.

Combination of 484 images of 20s each, no images were rejected, because going over each would take too much time. I selected ISO6400 because that ISO gives the lowest read noise on the Canon 6D. Processing this collection took almost 24h on my workstation. Capture sequence of the Canon 6D done by gphoto2 on Debian.

Final crop

100% crop of the central region of NGC7000 of the final image stack. The SNR is 22x that of the original, single frame. Its quite amazing to see what this difference in SNR will do! Lot's of intricate details are visible.

Raw crop

100% crop of the same region in a single sub of 20.8s. Image calibration on this sub was more or less the same as that for the final image. Many details visible in the final image are totally invisible in a single sub. Yet the signal is there, buried in the noise!

References   [ + ]

1., deepsky section, image of M31 27-08-2014 using 30s subs

Image information

Dark nebulae, Emission nebulae