Veil Nebula in NHO

The Veil Nebula is a supernova remnant in Cygnus about 1,400 Light Years away. Because it glows brightly in Narrowband wavelengths it is a favorite target even within city limits. The filters remove city lights and even moonlight.

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. I published a mosaic of the full Nebula in H alpha in Aug 2011. This page describes my work to build a central slice from West to East using all 3 filters. As I describe below I intend to take some additional images in 2012 so the entire Veil is captured in color.

Veil Nebula in False Color
Copyrights for Photos

East to West Slice

Color images are captured using filters. In my case I used filters that only transmit light from specific atoms (Hydrogen, Nitrogen, and Oxygen). Thus the intensities map the amount of each element at each pixel location. This is made visible by assigned the product of a particular filter to a color (e.g. the Hydrogen signal to Green). For this image I used the mapping

Nitrogen = Red
Hydrogen = Green
Oxygen = Blue

Due to the size of the slice 3 overlapping images were required to span it. To capture a color image the 3 areas are photographed with each of the three filters with an exposure of 12 minutes. Repeat the previous step about 50 times. See below for how many images were required.

For an identification of the structures in the image see Steve Gottieb's work.

In this image W is to the right and N is at the top.

Click for a 1/3 size image

Scrollable Full Size

Because the full image is so large (5815x3535) it is really too large to distribute. Since a lot of the detail shows when you scan into the image, I am presenting it as a Zoomify image. This will allow you to scroll into whatever structure you want to look at in more detail.

Views of the Three Principle Sections.

Here are near full size images of the three principle sections. Click on any of these for a larger view.

East Veil

NGC 6992 and 6995

Central Veil

Pickering's Wisp and the Thin Thread

West Veil

NGC 6960

Work for 2012

While my sections covered most of the Veil it did not cover it all. Since it will no longer be possible to get enough data to complete the project in 2011, I will have to schedule it for 2012. The picture below will give you some idea of what remains. The missing full color sections are replaced by H alpha only images which appear as B&W.

How Much Data?

To get the quality I need I gathered data virtually every clear evening from mid June to the end of September.This will give you an idea of how many subexposures were used in the final images. Each exposure was 720 seconds.

Section	Filter	# Exposures	Total Time (min)
East	H	39	468
	N	46	552
	O	40	480
Central	H	53	636
	N	47	564
	O	43	516
West	H	45	540
	N	44	528
	O	51	612
			4896 (81.6hrs)

And this was just the exposures that were good enough to be included. At least 20% of the exposures were culled.

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.

rjh 7/22/16