M76 (NGC 650/651) is a planetary nebula in Perseus known as the Little Dumbbell Nebula. It is one of the faintest Messier objects and one of only four planetary nebulae in Messier’s catalog.
A planetary nebula is from an exploded star, in spite of its name .
The Antares – Rho Ophiuchus is low enough in the southern sky that I have to catch it while it is as high as possible but before it creeps behind the wall of my windbreak. It is a wide field area so instead of using the camera and scope in the observatory, I set up my modified Canon Rebel with a Canon L zoom lens on my Losmandy G-11 mount on the outdoor cement pier. Almost a year earlier I had set myself a tickler to look for an opportunity to capture this image while it was in the right part of the sky. I really should have just set up in the driveway on the tripod, like I did in the good old days, where I would have had a much longer view without obstruction. But I keep coming up with low objects I want to shoot and I keep having to use the tripod to find a place where I can reach them. Since I didn’t build the outside pier and windbreak for nothing, I used it this time, dammit.
The big surprise was the coma effect on the stars in the corners. I didn’t expect that from an L lens. Makes me appreciate the quality of the glass and configurations of the telescopes I use more. Next time I will stop down at least one stop. I also tried to use a nifty piece of freeware in processing called Dark Master which matches the temperatures of the dark calibration frames with the temperature of the light frames. But instead of helping, it introduced some serious artifacts. I was doing something wrong so I just skipped the darks and used flat and bias calibrations.
It is a crazy gorgeous region in the sky and while I may not have done it complete justice, I’m glad to have it in my gallery.
• Location: Torrey, UT • Exposure: 2 hours 45 minutes, 5 minute subs • Lens: Canon EF 24-105mm f/4 L IS USM at f/4 • Mount: Losmandy G11 • Autoguider: Orion Starshoot • Guide-scope: ShortTube 80mm f/5.0 refractor telescope • Camera: Gary Honis full-spectrum modified Canon T1i (500D) • White Balance: Daylight • Mode: Raw • ISO: 800 • Acquisition and guiding software: BackyardEOS, PHD2 Guiding • Calibration: Deep Sky Stacker (no darks) • Processing: Photoshop CS5
The observatory threw every thing wrong that could go wrong at me and I have not been able to get an image since early November. The first sets of color captures combined in such a horrible way that it made me wonder if I knew which filter was which in the filter wheel. That is a tricky thing to figure out remotely. Turns out I had it right and the inability to make a workable RGB image remains unexplained. I even had a long online chat with the software developer of CCDStack. He had some usual good ideas that were subtle and subtler but no basic explanation of where things went off the rails. So, as is always a good idea, I just started over. I used 360 second 2X2 RGB frames with new calibration subs and masters. The LUM frames were not great but were workable with 10 minute unbinned subs, all unguided. The usable frames came to a total of 13.3 hours of exposure. I also re-ran, a couple of times, the mount tracking protocols including a 100 star T-Point calibration and a new PEC correction. Even if you don’t understand what all this means you get the point that running this thing is technical and demanding for the mere layman such as me.
Cepheus is looking bad in the depiction Stellarium uses in their Western constellation art. The picture shows an old man sitting around in his bathrobe. It could be me in this pandemic if I had more hair. I would be offended if I were him. That depiction is way too close to the truth, too exposing, not nearly romantic enough. It is the women in his life making the big splash. He is just a geezer hanging out in lazy togs for everyone to see, reminding people innocently passing by, if they will listen, that he prefers to be called King. There you are old dad, taking up space in the sky, trying to think somehow you might be important. An old man’s lament.
I switched the observatory camera from the original CCD SBIG ST-10XME to my modified CMOS Canon 500D/T1i. Replacing the observatory camera was more work, of course, than envisioned. The Canon sensor is set back compared to the SBIG’s and there was not enough range for the TEC-140 telescope to get focused. Jeff Dickerman, the super helpful president at Optec, made me a new adapter to go with another receiver that shortened the camera train enough to get easily into focus. I then rediscovered (I had forgotten but found my own online forum entry!) that CCDAutoPIlot had to turn off the feature on TheSkyX that would record both RAW and FITS files and records only the FITS files. It turns out the DeepSkyStacker can work with FITS and convert the RAW files that create them in color. But I had over time come up with a dark library in RAW frames for the Canon so I could temperature match with the light frames. I don’t have such with FITS files. But if I want to use the observatory automation of CCDAutoPilot, which I do, I will need a new FITS library at a range of temperatures to do it right.
Then I had trouble with setting exposure with CCDAutoPilot on the Canon images. I’m telling a lot of technical info here, but it took a lot of wrestling directly with complex technology to get through all the unforeseen obstacles. The Canon CMOS sensor uses a 2X2 Bayer matrix to record color. Two cells of the matrix are green, the other two are red and blue each. CCD’s, like my SBIG camera,have individual sensors not organized in a matrix. In something to do with the CMOS Bayer matrix, CCDAutoPilot only sees one cell as exposed, and it was saturated, while the other three were only about one-fifth exposed. It averages them in a meaningless way and it seems hit or miss if CCDAutoPilot can get the exposure close enough to get flats. Sometimes it gives up, sometime it settles on something. Focusing is tough too, as is plate solving. CCDAutoPilot did not have a solution as you can see on their forum here, but John Smith, the creator of the software, encouraged me to investigate on my own further. You are getting in pretty deep when the software designer basically gives up and says good luck.
Weirdly, after all that, I did come up with the image below.
The Trifid Nebula is one of the most popular objects to be viewed and photographed by amateurs like me, but if you are in mid North America you have to be quick, it isn’t up for long. In mid-August it doesn’t get fully dark where my observatory is in Torrey, Utah until 10 PM. At that time the nebula is due south, right at the meridian, and at its highest point in the sky for the night at a low 26 degrees altitude (90 degrees is straight up). Boulder Mountain is south of Torrey and it is as dark as it gets in that direction, so it is a good place and time to photograph the object. But by 1 AM the Trifid is getting below 20 degrees altitude, getting close to the mountain and running into too much atmospheric interference near the horizon. The trick is to get some moonless, cloudless nights at these few critical hours. Mid-August worked out this year.
I’m working on weaning myself as much as practical from social media. I have previously written how the largest corporations today, primarily all internet related, are dangerously sucking all the oxygen out of the economy. I don’t want to be a part of that travesty if I can help it.
I have been posting my astrophotos on Facebook where I get by far the most response. But I want to lay lower playing that game. I have ad blockers and add-ins that keep me from being tracked, but I want to spend less and less actual time there. I also use DuckDuckGo to search instead of Google, have dropped my Amazon Prime, and the only Apple product I use is an old iPad to stream Spotify. It’s a start.
As part of that start I want to post my astrophotos here instead of Facebook. I may not get as much attention. I hope to be grown up enough to be fine with that.
Here is one of my latest images. You can click on it to go to my astrophoto gallery on this same website to see a larger version and to find brief technical information about how it was acquired.
The Veil Nebula, sometimes called “The Witch’s Broom” is in the constellation Cygnus. Some 5,000 years ago, give or take, a star went supernova and this image is a piece of the remnant. The full circle of the remnant takes up about a three degree circle in the sky equaling a space about six times the diameter of the moon. With instruction manuals, trial and error and plenty of help from experts on amateur forums, I point the observatory telescope to a pre-identified place using sophisticated, automated equipment and capture the sub images. William Herschel, on the other hand, made his own telescope and found the object for the first time in 1784. No digital cameras were involved.
I am able to get close enough to the heavens to take photos of deep sky objects from my driveway on the Colorado Plateau because I am standing on the shoulders of giants. This subtle jewel of a galaxy first picked up it’s nick name in February 1787 when William Herschel wrote in his observing notes, “A very remarkable object, mE. [much elongated], about 12′ long, 4′ or 5′ broad, contains one lucid spot like a star with a small black arch under it, so that it gives one the idea of what is called a black eye, arising from fighting.” Continue reading →