NGC 6979 - Fleming's Triangular Wisp and Pickering's Triangle

NGC 6979 in HOO

Well it's been over 5 months since I've been able to image anything - lots of reasons, including the cloudy/rainy skies, busy at work, and telescope equipment failures. But over the past two weeks the skies cleared, equipment repaired (or replaced in some cases) and I was able to get back out under the night sky.

I spent a good amount of time on M16, the Eagle Nebula, but this past weekend I managed to capture part of the Veil nebula, Specifically, Fleming's Triangular Wisp and Pickering's Triangle. The entire Veil is large - it is made up of the visible portions of what is known as the Cygnus Loop, a supernova remnant. Many portions of the nebula have acquired their own individual names and catalogue identifiers, hence the long title.

The entire nebula is too large to capture in one image. The source supernova was a star 20 times more massive than the Sun, which exploded around 8,000 years ago. The remnants have since expanded to cover an area of the sky roughly 3 degrees in diameter (about 6 times the diameter, or 36 times the area, of the full Moon). The distance to the nebula is not precisely known, but is believed to be about 1,470 light-years.

NGC 6979
August 10-11, 2019   WO GT102 APO (4" Refractor)
ASI1600 mm Pro  8.3 Hours (50x300sec Ha; 50x300sec Oiii)

Here are two pieces of the nebula taken in bi-color, narrow-band imaging. Fifty exposures (or subs as we astrophotographers call them) were taken with a Hydrogen Alpha filter (Ha) and fifty with an Oxygen Filter (Oiii). These filters allow only a very, very narrow wavelength of light to get through to the camera's sensor. Since supernova remnants glow in both Ha and Oiii the use of these NB filters is ideal. The added benefit is that all the light pollution (and even the nearly full moon at the time of the image) is almost completely eliminated!  The center top of the image is Fleming's Triangular Wisp; the larger portion, to the right, is Pickering's Triangle.  The full resolution image can be found on Astrobin where I keep all my photos.

Later this summer I may try to capture the whole Veil using a process known as mosaic imaging where the telescope takes different subs from different parts of the sky and then stitches them together to form a whole image.  This takes a lot of time and all the equipment needs to be operating at peak efficiency.  

Later this weekend I will be processing the images I took of M16.  Look for M16 soon.