Return to the Pelican Nebula
Meanwhile, I continued as part of the HOYS-CAPS project @ University of Kent monitoring Young Stellar Objects (YSO) for outbursts. Currently, I focused one the region of IC5070 and during the time a lot of images of IC5070 has been collected. Beside the photometric monitoring, I started to stack all images to obtain a deeper and less noisy image of this region.
What do we know about this IC5070: this object located in the constellation Cygnus not very far away from Alpha Cyg (Deneb) as part of the overall complex together with NGC7000 (North America Nebula) seems to be about 600pc away and spans about 9pc. The shape of the pelican is made on hand side out of dust (the eye - which is not in my image and would be more to the left) and the neck which is defined by the hydrogen emission region (which I focused on). A image with better overview can be found for example in the APOD's. The whole complex is connect to molucular clouds and a star formation region - similar like the Orion Nebula Complex.
Left: RGB-Red single image, 600s
STL 11000, Binning=1
Comparing both images you can observe the effect of massive stacking. We have to major effects:
- improvement of noise: fainter structures getting better visible.
- improvement of S/N: S/N increases roughly in terms of square root of number of images, in this particular SQRT(56) = 7.48. Stacking of 56 600s images corresponds from S/N perspective to a single exposure of about 4490s = 1h 15min.
Detailed comparison shows that my 9.3h exposure has less noise and looks even deeper than DSS2 of this particular region. Analysis of the R-channel turns out the my image goes down to 21.5mag.
Keeping in mind that I suffer from sodium vapour lamp light pollution, I consider this as a good result.
In parallel I've also perform images in RGB-Green as well also some - not to the same extend as done for red and green - broad band RGB-Blue images.
IC5070 (Pelican Nebulae)
RGB-Broad Band Filters, Exposure times:
And the work will continue...