Day three of my cold brought, as predicted, sneezing and runny nose. I had taken a non-drowsy Sudaphed earlier, but after the four hours had elapsed, I still felt not too stuffy, so I didn't take another. I wish I had! Sitting outside at the observatory had my nose running like a water faucet. I quickly ran out of tissues from my car's tissue box, and I had to grab a roll of toilet paper from the observatory bathroom. I finished off two-thirds of the roll before the end of the night! I certainly sounded sick, even if I didn't feel very sick. By the end of the night though, it had started to move up into my head - my ears were ringing, meaning sinus pressure was building. Boo!
I got out to the observatory around 7 PM, and rushed to pull out the hydrogen alpha solar scope to grab a quick set on the sun before it dipped behind the trees. Still no sunspots, but a cool plage region to add some intrigue!
The "difference" mode when I placed the shorter-exposure granularity image on top of the longer-exposure prominence image to combine the two (difference helps to align the two images)
Colorized to "look like the sun"
Details:
Date: 13 July 2018
Object: Sun
Camera: ZWO ASI1600MM Pro
Telescope: Lunt LS60THA 60mm pressure-tuned (500mm FL)
Accessories: N/A
Mount: Celestron NexStar SE
Frames: 1: 1313/2004
2: 1847/2002
FPS: 68
Exposure: 1: 10 ms (granularity)
2: 100 ms (prominences)
ISO/Gain: 0
Stacking program: RegiStax 6
As it sank behind one of the taller trees, I caught it on video: Maple Eclipse of the Sun!
My minion Miqaela joined me again that evening for another night of imaging on her borrowed Explore Scientific ED80 refractor. After seeing how well I was able to image M51 Whirlpool Galaxy on a refractor, she wanted to try as well, with her Nikon D5300. Fellow club member Bob joined us as well, but without his scope, so he wheeled out the club's big juicy 16-inch Dobsonian. Fellow club member Perry joined us as well, bringing his 8-inch Meade Schmidt-Newtonian out for its first trip to the observatory. I was shocked that it was such a small group; a clear, moonless, and warm Friday night, and no one else wanted to come out?? Well they missed out!
While waiting for it to get dark, I get a head start on imaging by turning to something you don't need a lot of darkness to image: the planets. First was Venus, before it too went behind the trees. I tried to image it on the DSLR on the club's 5-inch Vixen refractor a while back, but it was tiny and basically just chromatic aberration all around. I didn't even talk about it in my log entry, apparently! This time, I used my 8-inch Schmidt-Cassegrain, which I had left set up from Thursday night on my Celestron Advanced VX mount, with my Borg 76mm apochromatic refractor riding on top for auto-guiding. I did leave my f/6.3 focal reducer on so that I would be focused and ready to go by the time it got dark enough to fine-tune my alignment model and then start imaging, but it came out quite nicely anyway!
Details:
Date: 13 July 2018
Object: Venus
Camera: ZWO ASI1600MM Pro
Telescope: Celestron C8
Accessories: f/6.3 focal reducer, Astronomik LRGB Type 2c 1.25" filters
Mount: Celestron AVX
Frames: L: 672/2004
R: 525/2011
G: 641/2012
B: 1060/2004
FPS:
Exposure: L: 0.1 ms
R: 0.5 ms
G: 0.5 ms
B: 0.5 ms
ISO/Gain: 139
Stacking program: RegiStax 6
Part of the reason I haven't imaged it very much is because my setup spot at my apartment is on the east side of the building, so it gets blocked by the building, and I didn't usually have my 8-inch out at the observatory, since I mainly go out there for imaging, and it's only recently I've been able to image once again with my 8-inch. When I was using my 11-inch, I have trouble pulling the planets into nice sharp focus on it - I might create an aperture mask for it at some point to sharpen the view.
After Venus, I slewed over to Jupiter, and grabbed a dataset on it too. I also went and looked at it through Perry's Schmidt-Newtonian. He had messed with the primary mirror a while back and now there's some chromatic aberration, but it was still a nice view. The "seeing" (measure of atmospheric stability) was excellent that night!
Date: 13 July 2018
Object: Jupiter
Camera: ZWO ASI1600MM Pro
Telescope: Celestron C8
Accessories: f/6.3 focal reducer, Astronomik LRGB Type 2c 1.25" filters
Mount: Celestron AVX
Frames: L: 668/2014
R: 468/1670
G: 490/1404
B: 970/2014
Exposure: L: 4 ms
R: 10 ms
G: 10 ms
B: 12 ms
ISO/Gain: 139
Stacking program: RegiStax 6
No Great Red Spot, and it's not my best image of it, but still got some nice cloud swirling detail. One of the things I love about my ZWO ASI1600MM Pro is that it's USB 3.0, which means when I crop down to a small frame size for imaging a planet, I can get 60+ fps, which lets me take a whole lot of frames very quickly. This is important for Jupiter, since it rotates quickly.
Later on, Perry called us over to his scope to watch Jupiter's moon Europa disappear behind the planet. It was neat to see it just hanging on to the edge for a few minutes!
It was getting darker now, but still not dark enough to start deep sky imaging, so I followed up on minor planet Vesta. I imaged it Thursday night as well, and the plan was to superimpose the two images together so you could see its motion. I did a Precise Goto, and recognized it in the 10s preview frames as having moved out of the trapezoid of stars it was in the day prior. I uploaded a jpeg screenshot to astrometry.net to confirm.
Since it didn't identify it as a star, it has to be Vesta. I double-checked it against the position of those labeled stars in SkySafari. A match! I took 10x60s subframes (and forgot to turn on guiding, so I only had one or two stable ones).
I picked a frame from Thursday night and a frame from Friday night and put them into DeepSkyStacker to register and align. I "stacked" them using the Average stacking mode, since all others looked terrible because I accidentally took jpegs the second night. Since Average mode averaged the light from Vesta over its two positions, I cropped out Vesta from one of the single frames and placed it on top of its two positions in the final image so that it wouldn't look weirdly dim for its oversatured size. In reality, it's only 0.5 arcsecs across, which with the resolution of my camera and telescope together being 0.6 arcsecs, is less than a pixel. But its light spills over across many pixels, indicating how bright it is - similar to how a bright star or planet looks bigger than the others to your eye.
Date: 12 & 13 July 2018
Object: Vesta
Camera: ZWO ASI1600MM Pro
Telescope: Celestron C8
Accessories: f/6.3 focal reducer, Astronomik L Type 2c 1.25" filter
Mount: Celestron AVX
Guide scope: Borg 76ED
Guide camera: QHY5
Subframes: 2x60s
Gain/ISO: 300
Stacking program: DeepSkyStacker 3.3.2
Stacking method (lights): Average
I measured the distance it had moved by measuring the number of pixels between the centers of each image of Vesta using the ruler tool in Photoshop, and then converting that to arcseconds and then arcminutes, knowing what the spatial resolution of my camera is.
Not only are Jupiter and Mars gorgeous right now, but Saturn pass through opposition just a month ago, and while it's not as bright in the sky as it was last year, it's phenomenal in the telescope! I looked at it in Perry's Schmidt-Newtonian, and WOW it was gorgeous tonight. Cloud bands, Cassini division, and brilliant color! So I ran over to my scope to image it too. I had the focal reducer on in prep for imaging deep sky objects later, so it's not quite as sharp (due to it being really small in the field-of-view), but still pretty!
Date: 13 July 2018
Object: Saturn
Camera: ZWO ASI1600MM Pro
Telescope: Celestron C8
Accessories: f/6.3 focal reducer, Astronomik LRGB Type 2c 1.25" filters
Mount: Celestron AVX
Frames: L: 721/2010
R: 865/2005
G: 565/2003
B: 1490/2010
Exposure: L: 25 ms
R: 50 ms
G: 50 ms
B: 100 ms
ISO/Gain: 139
Stacking program: RegiStax 6
After I finished grabbing Saturn images, there were enough stars out to firm up my polar alignment, if I cranked up the gain and exposure time. I went into SharpCap and ran its polar alignment routine again, and it came back with "fair," as opposed to Thursday night's "Excellent." I find that re-polar alignment is necessary from night to night on non-permanent rigs - they tend to shift around, either when taking gear on and off, covering and uncovering the thermal blanket, and maybe wind or settling into the grass. I made the adjustments and got it back to "excellent," and then re-aligned. My gotos still weren't very good for some reason, so I had to go a Precise Goto for every object. Those worked pretty well.
My deep sky task for the evening was to take advantage of the very clear skies and stable atmosphere and collect a bunch of luminance frames. My first goal was M20, the Trifid Nebula, which I had collected color frames on the night before. I tried to take 5-minute subframes, but that proved too long for the guiding error that was cropping up. It looks periodic in my 3-minute subframes, so I might try to train PEC (periodic error correction) my next night out. I haven't actually tried it yet.
Yucky, elongated stars on one of my 5-minute images. And several of my 3-minute frames.
After I got home and stacked it the next day, it came out rather nice!
Date: 12 July 2018 (RGB), 13 July 2018 (L)
Object: M20 Trifid Nebula
Camera: ZWO ASI1600MM Pro
Telescope: Celestron C8
Accessories: f/6.3 focal reducer, Astronomik LRGB Type 2c 1.25" filters
Mount: Celestron AVX
Guide scope: Borg 76ED
Guide camera: QHY5
Subframes: L: 17x180s (51m)
R: 6x180s (18m)
G: 8x180s (24m)
B: 9x180s (27m)
Total: 40x180s, 2h
Gain/ISO: 139
Stacking program: DeepSkyStacker 3.3.2
Stacking method (lights): Auto-Adaptive Weighted Average
Darks: 20
Biases: 20
Flats: 0
Temperature: -20C (chip)
Got some nice structural detail in the emission portion of the nebula, as well as the dark bands! The blue was hard to pull out, mainly thanks to light pollution, since it's a dimmer region than the red. If you look really close, you can almost see the two narrow antennae coming off of the big lobe that's in the top left edge of the red emission region.
I use a Microsoft Surface 3 tablet (not the Pro) to run all of my capture software. It's great because it's portable, has a long battery, and charges on a micro-USB port that can be plugged into a cell phone external battery, if needed. Since my cameras suck a lot of power, though, I have to make sure I run it on a 2.4A power supply, or else it will deplete faster than it's charging. One of the only downsides to it is the hard drive space - mine has 128 GB, 50 GB of which is the operating system. For deep sky object imaging, this is no big deal - a typical 2-4 hours of imaging is only a couple of gigs, since each frame is only 32 MB. Things get tricky though when I do planetary imaging, since I'm taking videos with 2000 frames per color channel. Even when saving out in the LuCam .SER format (which RegiStax loves and is suuuper quick with, by the way), which are much smaller than AVIs, that's still nearly 1 GB per video file, or 4 GB per target (since I need luminance, red, green, and blue). This adds up fast when you do multiple targets, and my hard drive filled up! I had to clear all of the movies off of my micro SD expansion card in order to copy over all of my planetary data from that night.
While those were going, we rotated around between looking at Saturn, Jupiter, and later Mars in the 16" Dob and Perry's Schmidt-Newtonian. I tried to find M51 Whirlpool Galaxy in the big Dob on my own, which I had never tried before. I got close, but it turned out to be very hard to see against the background light pollution. Way different than West Virginia!
When Mars was up later, we put a high-magnification eyepiece on it, and I observed it while playing Gustav Holst's "Mars, the Bringer of War" on my phone. It was a magical experience. 😍
Once I had about two hours of luminance data on M20, I decided to collect some luminance data on another target as well, since the sky was so good, and I didn't have to be anywhere in the morning. I wound up going with M16, the Eagle Nebula. Light pollution made it mostly a flat gray besides the pillars, but using some of Carboni's Photoshop tools - "Light pollution removal enhanced flatten" and "Enhance DSO reduce stars" - brought out a bit more contrast. I got some nice detail on the Pillars of Creation, despite my slightly stretched stars!
Date: 13 July 2018
Object: M20 Trifid Nebula
Camera: ZWO ASI1600MM Pro
Telescope: Celestron C8
Accessories: f/6.3 focal reducer, Astronomik LRGB Type 2c 1.25" filters
Mount: Celestron AVX
Guide scope: Borg 76ED
Guide camera: QHY5
Subframes: L: 16x180s (48m)
Gain/ISO: 139
Stacking program: DeepSkyStacker 3.3.2
Stacking method (lights): Auto-Adaptive Weighted Average
Darks: 20
Biases: 20
Flats: 0
Temperature: -20C (chip)
It was about 3:30 AM by the time I'd collected about 30 subframes on the Eagle Nebula, and I decided we'd probably better head out. Hopefully I'll get another chance soon to get the color images. Normally I don't stay out there past 2 AM unless I'm going to camp out, since after that point I'm usually too tired to drive home safely, but since I had woken up at 11:30 that morning, I had a little extra time on my hands. There was one more thing I wanted to image, however: Mars.
I couldn't see much of any surface detail on Mars in either one of the visual telescopes out that night, but I went ahead and imaged it anyway. Despite not being able to see much, the camera somehow did, and I got a decent image! It would have been better if I had taken off the focal reducer, but it was late and I didn't think about it, plus I still needed it for Vesta so that my images would match from the night before.
Date: 13 July 2018
Object: Mars
Camera: ZWO ASI1600MM Pro
Telescope: Celestron C8
Accessories: f/6.3 focal reducer, Astronomik LRGB Type 2c 1.25" filters
Mount: Celestron AVX
Frames: L: 701/2020
R: 655/2018
G: 450/2020
B: 578/2014
Exposure: L: 1.5 ms
R: 3 ms
G: 5 ms
B: 14 ms
ISO/Gain: 139
Stacking program: RegiStax 6
You can see the polar ice caps, dark terrain features, and its tenuous atmosphere on the edge! Mars is so awesome right now. Yes, it is the giant, bright orange thing hanging low in the southern sky after 11 PM, as many of my friends have asked me. And it's a real treat to look at in the telescope!
Finally, around 3:45 AM, it was time to pack up. Saturday night was not looking very good, and honestly I was pretty sure my body couldn't handle another night. I contemplated leaving my gear setup and coming back out to clean up the next day, but I knew I would probably regret it, since the sinus headache was already beginning to tug at the corners of my head. I convinced Miqaela it would be a good idea (she doesn't have her key yet, so she could only come back if I came back), and we packed up and headed home. I even hauled all of it inside when I got home - it takes 7 trips to get it all up the stairs and into my apartment! I hope my downstairs neighbor is a deep sleeper...
That's the mount, 8-inch Schmidt-Cassegrain, Borg 76ED in a Pelican case, tackle box full of tools, nuts, bolts, velcro, batteries, adapters, and anything else that comes in handy, accessory box with dew heaters, towel, power strip, extension cable, and other larger helpful items, counterweights box, ZWO camera bag, DSLR camera bag, telescope tripod, camera tripod, tablet, folding table, chair, and bag of warm clothes.
So the last week was a hardcore marathon of astrophotography! 17 data collects, four telescopes, 7 nights, and not enough sleep! It will take some time to recover, especially from this cold I'm still in the midst of as I finally get around to writing this on Sunday, but as always, it was totally totally worth it. Perry asked how I do it - "must be lots of coffee, and your enthusiasm helps, I'm sure!" he said. My response: "Coffee, enthusiasm, and sheer willpower!"
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