Ballard Loc: Grass Valley, California

Although not as famous as M42 the Orion nebula, M17 is also a star forming region. This nebula has been given a number of names including the Omega, Swan, CheckMark, Lobster and HorseShoe Nebula, it kind of depends on how much you had to drink before looking at it through a telescope. It resides in the constellation of Sagittarius and contains an open star cluster (NGC 6618) within it that was formed by the gas in the nebula and is what lights the nebula up. The nebula is ~5000 light years away, is about 15 light years across and contains the mass of 800 suns.
The first image below was constructed from Luminance, Red, Green and Blue images I took over the past couple of nights.
The second image used data taken with a 5nm Hydrogen Alpha (Ha) filter for the Red channel and the same luminance Green and Blue data as the first image.
The third image used the Ha data for both the Luminance and Red channels.
The fourth image is just the monochrome narrow band Ha data which this nebula seems to have a lot of.

I also used the high dynamic range (HDRmultiscaletransform) tool in pixinsight to bring out more of the detail in all the images.
All questions, comments and suggestions are welcome.

For those interested all images were taken with a 16 inch Meade LX200 Schmidt Cassegrain telescope with a focal length of 4064 mm. The camera used was an ASI 6400MM pro monochrome camera with the temperature set to -12 C, binning set to 1x1, and gain set to 100. All appropriate Flats, dark and bias frames where used for image calibration.
The following exposures where use to capture the data. (The somewhat odd numbers are due to throwing out a few of the frames when the seeing fuzed out a bit causing the FWHM (Full width at half maximum) of the stars to get a bit bigger than the other frames.)
Luminance 133 frames each 1 minute long.
Red 71 frames each 1 minute long.
Green 76 frames each 1 minute long
Blue 74 frames each 1 minute long
Ha 36 frames each 3 minute long
Total exposure time 7 hours 42 minutes.
Note: I'm currently taking some narrow band O3 and S2 images and hope to have a full narrow band image out in a few days.

LRGB image of the Omega Nebula

(Download)

L-Ha-GB image of the Omega Nebula

(Download)

Ha-Ha-GB image of the Omega Nebula

(Download)

Monochrome HA data of the Omega Nebula

(Download)

Stu A Loc: Portsmouth, Ohio

Ballard Loc: Grass Valley, California

Hi Stu A
Thanks for viewing the images of M17 and for the Thumbs up.

SonnyE Loc: Communist California, USA

Very nice, Ballard!
I like the variations.
Yep, my dismay is all the candy store acronyms being plopped on what was fairly traditional names.
I tried to get Sellarium to find M8, the Lagoon Nebula. I couldn't find M8.
But no problem finding Lagoon Nebula. Maybe whoever is behind this word salad is trying to obliterate Messier?

Ballard Loc: Grass Valley, California

Hi SonnyE
Thanks for checking out the images of M17. Interesting that Sellarium knows about the Lagoon Nebula but not M8. I normally use "The Sky" on my laptop it knows it by both names as well as by NGC 6523. Last night got a few more Ha's in, as well as O3 and S2 shots on M17, but haven't had time today to put them all together. I'm going to try some narrow band imaging of the Soap Bubble nebula in Cygnus over the next few nights if the weather holds up.

SonnyE Loc: Communist California, USA

I would think the Messier list would be paramount. But I guess somebody working on Stellarium doesn't think so.
My plan is to do all narrowband tonight. Last night was supposed to be LRGB and HA. But the HA was a fail.
So going back for more tonight.
Sounds confusing, sorry. I'm on to M16 last night and tonight. I usually keep swinging away at something until I get enough data.
So far we are doing a heat wave here. So the nights are kind of warm.
Being a dabbler, I just delete stuff I don't like. Last nights HA adventure wound up with 2 keepable out of 20 images. So I deleted the whole HA attempt.
Tonight's a whole other chance to do good.

Good luck with your endeavors tonight, and every night.

Ballard Loc: Grass Valley, California

You would think that Messier would be the best known name but I guess they had different ideas. It is warm here also (almost 11:30PM and still in the high 70s). The peltier cooler is running at 100% and can only get the chip down to -8C. On the good side the sky is very stable and I am getting .37 RMS arc second tracking. I'm currently running with Ha tonight and trying for 40 exposures at 500 seconds each. In each exposure so far I can just see the faint outline of the Soap Bubble nebula. Good luck with your imaging also.
Below is one of the 500 second Ha subs that I just took. It has been stretched and saved as a jpeg with the compression turn up to get the file down from a 55meg jpeg down to under 20meg to fit on the website (no calibration or other processing has been done).

Look for the round bubble in the center of the image

(Download)

SonnyE Loc: Communist California, USA

Looks very nice!
I was having focuser issues. By the time I got those straightened out, the rig went into a Meridian flip.
I went out to watch it do it and immediately smelled rain. Everything was still dry, but there were some faint clouds overhead.
Given the evenings problems (now fixed), I decided to quit and bundle things up for the night. Better to quit and save it for another day, than to get things wet. Everything is working relatively well now. No sense messing it up.
Late night clouds tonight and tomorrow night, but clear into Wednesday after that.

I might drop back to NINA 2.2x. It was good and stable. But the 2.3 version seems to be troublesome for me. Or at least for my Pegasus focuser since the latest Microsoft updates. Acts like driver problems.
One step foreword, two steps back.

Hope things hold for you and you can get your Bubble Nebula data. Looks great so far.
Night now.

stepping beyond Loc: usa eastcoast

I'm ecstatic that your getting the guiding that tight with that 16" big sail on your rock solid mount , you got it going on Ballard . The heat here is STUPID hot and humid, last night received 7/10" from a heat thunderstorm, which is good, I don't have to water the gardens.

alberio Loc: Casa Grande AZ

Wow, that big gun really brings out the faint nebulosity. Good work as usual.

bwana Loc: Bergen, Alberta, Canada

I opt for the 1st and last images. Lovingly done!

bwa

Ballard Loc: Grass Valley, California

Hi SonnyE
Always better to play it safe when it comes to possible rain. The night held out for me and I got 38 good frames out of 40. (2 had an FWHM a bit worse and fewer stars than the other frames, so I tossed them out). As the night progress it cooled a bit more and the camera got closer to the -12C I was shooting for( around 1/2 of the frames were taken at -10C and -11C, the others were -8C and -9C. In any case I used the -12C darks to calibrate them and then stacked them (see image below). Tonight looks like the clouds will be coming but I can get some dark frames in at -8C for better calibration on the warmer frames. I expect that I will want another full night of just Ha to get the noise down a bit more, however the next few nights might be iffy with clouds going by so it may be another week or more before I can get all the different filter shots in I want.

Stacked, Denoised, Stretched and a bit of star reduction for the 38 Ha frames. (integration time 5 hrs:16 min:40 sec)

(Download)

Ballard Loc: Grass Valley, California

Hi Stepping beyond. Thanks for the comment, last night things were working well. The days currently have been over 100F and didn't get below 72F all night. Clouds are moving in now so I expect it will be a few days before I can collect more data on the Soap Bubble nebula.

Ballard Loc: Grass Valley, California

Hi alberio
Thanks for the comment. The 16 inch works well although the F10 focal ratio makes for long exposures of the really dim stuff like the Soap Bubble nebula I just started working on.

Ballard Loc: Grass Valley, California

Hi bwa
Thanks for checking out the shots of M17 and for the comment. I got a few more chores to work on today but hope to get back to processing the narrow band Ha, S2 and O3 data on M17.