M16, the Eagle Nebula, in Ha only

M16 - The Eagle Nebula - July 25 & 27, 2019
WO-GT102 APO (4" f/5.6) refractor and ASI1600mm Pro Camera
42x300 sec Ha subs

Summer offers some of the most interesting and colorful deep space objects in the night sky. This is because the arm of the Milky Way stretches up from the southern horizon revealing a bunch of bright nebulae. Unfortunately, my telescopes are set up in my backyard and the property is sort of "in a bowl" so to speak - trees line the horizon all the way around blocking any object lower than about 20-25 degrees in altitude. So whenever the skies are clear enough to capture some of these objects I have a limited window in which to get them.

Over the last month or two I've been attempting to capture M16, the Eagle Nebula, in SHO narrowband. As I mentioned in my last post, I ran into all kinds of problems - equipment failures, cloudy or poor sky conditions, etc. Bottom line is that never got good data in Oiii or Sii (the O and S in the SHO Hubble pallette). Not to let that bug me I decided to take the good Ha data and process a monochrome, Ha-only image of M16.

So here it is in all its B&W glory. In turns out that monochrome Ha data can be extremely interesting as it tends to show more of the finer, more tenuous detail in the outer edges of the nebula. Once I get the remaining Oiii and Sii data I can reprocess the image in color - that is, if I can get the data within the next week or so as M16 is setting earlier and earlier each night and soon will be out of my view. Forecast is for clear nights this week, so who knows - maybe I can get the remaining subs.

The Eagle Nebula is part of a diffuse emission nebula, or H II region (Ha). This region is known to contain active star formation and is about 7000 light-years distant. The cluster associated with the nebula has approximately 8100 stars and it is this group of stars that are the source of the energy that makes the nebula glow. Because this was taken with my short focal length, wide field refractor, the famous "Pillars of Creation" are a bit difficult to see. The Pillars were made famous in a 1995 Hubble telescope photo and has become the most recognizable Hubble image. Maybe next year, when I replace my defective large scope mount, I'll capture this again with much higher magnification and resolution.

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.

Jupiter - a target again - amateur detects impact on the giant planet!

It has happened a number of times in the past - in fact, 7 recorded impacts since July of 1994.  Texas amateur astronomer Ethan Chappel recorded this latest impact while waiting for some Perseid meteors to flash across the night sky. His Celestron 8 telescope captured the event as a flash of light in the planet's South Equatorial Belt (SEB).

For more, read the complete story at Sky and Telescope.