Pickering's Triangle is a region near the end of the eastern Veil nebula at the north central edge of the huge super-nova remnant called the Cygnus loop.   It was discovered photographically in 1904 by Williamina Fleming after the New General Catalog was published so it doesn't have a NGC number.  At the time, it was customary for the director of the observatory to get credit for new discoveries, which is how Edward Pickering's name got attached to this region.  Pickering's triangle sits at a distance of about 2,400 ly in the constellation Cygnus.  It is bright, detailed, and colorful so it is a very popular target for imagers with almost any type of telescope--large or small.

After looking at the latest crop of Veil images this summer, I came to the realization that I had never once tried to image it.  Of course the Veil is huge so it's best suited to a wide field telescope and it helps if you can create a mosaic.  Armed only with my C14, the best I could do was to dive into a detailed region to see what I could pull out.  Pickering's Triangle is one of the more interesting compact regions in the Veil so it seemed like a good place to start.

I began this project during a new lunar cycle and that's how I started with the idea that I'd just do a narrow band image.  As usual, my optimistic view was that I could finish taking data while the moon was out and switch to something perhaps a bit more interesting when the sky darkened again.  Of course that was a completely absurd idea and I wound up spending two lunar cycles gathering data every clear night.  I was so fixated on taking narrow band data that I didn't even once think about grabbing some LRGB data along the way.  In hindsight, that would have been a good idea but, oh well--the original goal was to create a NB image and I blindly stuck to the plan.

The interesting thing is that when I'm imaging a galaxy where I want the best possible seeing, I almost always struggle with 2+" seeing conditions.  In this case, I had a huge object so of course the seeing was some of the best I've ever seen out at DSW.  I measured many subs with FWHM under 1.6" with a few as small as 1.3".  The overall median for each of the three channels might have been somewhere between 1.8" an 1.9", which is as good as I ever see for a batch of subs out at DSW.  My image yield was also extraordinarily high at over 90% for each of the three channels.  I did have to wait out a few long stretches of cloudy/windy/rainy weather during new moon, but when it was good, it was really good!

I ended up collecting a bit over 60 hours of data and my first idea was to process the data using the SHO palette.  You can see that result in rev B.  I didn't massage it very hard and it works but I didn't like it.  The main problem is that the S2 signal almost perfectly overlaps the O3 signal so I wound up with mostly just two colors in the result.  In this case, they were blue and yellow.  I could tweak the yellow to make it more orange (or even red,) but minor adjustments did little to produce anything very interesting.  I want to note that I have seen some very nice SHO Veil images and I probably could have blended the channels a bit but I decided that I didn't want to go further down that path.   Veteran Veil imagers here on AB could have told me to save my effort because this is a well known characteristic of the Veil and that's why a lot of folks simply create a bi-color image.  But, I wanted to experiment a bit to see what I liked.

So I regrouped and took a different tack.  Since Ha and S2 overlap, I simply combined those two channels and created a bi-color image.  I loaded O3 into B and G channels and loaded the Ha+S2 into the R channel.  This basically splits the color so that red correctly represents the actual red signal in the object and the blue+green color represents what the O3 filter passes.

The problem with the result is that this color assignment creates a striking red signal with a cyan/green, teal O3 color, which I didn't find particularly attractive.  To my eye, a red/teal image is just not very good looking palette.  So I after cleaning up the image, I used Photoshop to shift the teal color into a purely blue signal.  Hence, I arrived at the standard palette that almost everyone uses.  The nice thing is that if you image this object with LRGB, these are pretty much the colors you get.  And...had I been smart enough to gather some LRGB data, I would have mixed this NB data to get a result that you might see with your eyes if this object were bright enough.  As it is, this is a view of the nebula produced purely in the narrow-band light emitted by each element with the O3 signal shifted away from the green.  Maybe I'm just used to seeing it this way but I find this combination of saturated reds and blues to be pleasing.  I went a bit beyond my normal colorful processing style with this image by going with a highly saturated result--hopefully without going too far over the edge.  I liked the look of "embers in the "gas-burner" for this super nova remnant.  The intertwined bright colors also provide an interesting 3D texture to the filaments of interstellar gas.

The interesting thing about this image is that it reveals gobs of detail in the nebula.  Zoom in and look around.  The knots and tendrils of color provide a mesmerizing display showing how the elements are distributed and mixed in interstellar space.

As always, C&C are welcome.  Hopefully it works on your monitor as well as it does on mine.  Just be careful not to singe your retina!  If it does, let me know and I'll consider dialing it down a bit.

John