Veil Nebula

The Veil Nebula is a supernova remnant in Cygnus about 1,400 Lyrs away. Because it glows brightly in Narrowband wavelengths it is a favorite target even within city limits.

This project started out as just some Hydrogen Alpha images of the Western Part of the Veil (NGC 6995). When I saw how well the images from the first nights were coming out I decided to expand the project to the entire Veil. This page describes the mosaic of full nebula constructed from H alpha images. I am also working on Oxygen III and Nitrogen which will produce a false color image. For those pictures see the color Veil Page.

The images for this project were taken from mid June to Aug 2, 2011. On many of the nights there was significant moonlight, but the narrowband filter excludes most of the impact of the moon.

Veil Nebula
Copyrights for Photos

click picture for a 1/4 size image

1/2 scale image (6 Meg)

click for a larger map

Map courtesy of Steve Gottieb

Zoomable Full Scale Image

The full size image is huge. To make viewing reasonable on the Internet this is a zoomable image that will allow you to zoom in to see the details of the nebula structure.

Building the Mosaic

The image is made from 8 different panels. The principle panels are shown in the drawing below. Each subexposure was 720 seconds using a 3NM Astrodon Halpha filter.

click for a larger image

Panel	Number of Exposures
E	39
NW	35
S	33
W	45
NE	8
SE	10
SW	5
Center	7
Total	182

Altogether 2,184 minutes of exposures were used for the final mosaic or 36.4 hours. In all over 40 hours of images were taken and the poorest were culled.

The Mosaic was built from the following panels laid out about as you see below. Note there is considerable overlap between panels. Three corners and central section were mostly just stars so the final image does not have gaps. They contain fewer subexposures and thus are nosier. These are mostly overlaid with other panels. The NW corner contained the nebula. These images are a simple STF stretch without further processing.

Image Processing

The processing of these images follows the general steps in my Sample Workflow. All processing was done with PixInsight.

Calibrate
Register
Combine

The individual panels were then combined using StarAlignment. I tried to use the new Gradient Tool, but it encountered some problems.

The final image was produced using

Generate Range Mask(for deconvolution and atrous)
Generate Star Mask(for deconvolution)

Initial Image after combine

Deconvolution*
Atrous*

* The linked images are linear and were temporarily stretched with STF

Multiple Histogram Transformations
HDR Wavelets
ACDNR (2 passes)
Final HT to touch up the pedestal.
Curves to bring out contrast

final image

Zoomify was done with Photoshop.

Note that DBE was not required. The images had no detectable gradient even though many were taken with significant moonlight.

Copyrights for Photos

Except as noted, all work on this site by Robert J. Hawley is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License. This permits the non commercial use of the material on this site, either in whole or in part, in other works provided that I am credited for the work.