Sunday, June 28, 2020

#365 & #366 - Saturday-Sunday, 20-21 June 2020 - Astro-Camping Weekend!!

A little before 11 AM on Saturday, I was scrolling through Facebook and commented on my fellow astronomy club member Richard's post about his overnight trip to a secret dark sky site, expressing jealousy.  Another astro-friend of mine from the Sacramento astronomy club, Cary, commented that he and a few others would be spending the weekend up at the Sacramento club's dark site, and he invited us to join.  Needless to say, I was extremely tempted.  I immediately began to think if there was any reason I couldn't go, but nothing came to mind.  So I started packing!

The site was at an airstrip up in the mountains to the northeast of Sacramento, about 2.5 hours away from me inside the Tahoe National Forest.  I haven't camped since I moved out here to Berkeley last August, and my camping gear was scattered throughout the house.  They had electricity but no water.

I worked methodically through my mental packing list, going in sections: camping gear, clothes, food, and astronomy gear.  It ended up taking me about 4 hours to get everything organized and loaded into the car, and another hour at the grocery store.  But I finally hit the road at 4:30 PM.  I have to say, I love my Paramount MyT even more now; it's so easy to tear down and set up!  Just two pieces: the tripod and the mount.  (Well, and the counterweight bar and counterweights, and telescope of course).  I've got my cables all bundled up in cable wrap, and all my power cables and adapters contained inside a rainproof box, so everything stayed pretty organized.  

The site

Getting to the site was pretty easy -- the airstrip is just off the freeway.  It's currently only used by Cal Fire during wildfire season and by student pilots who practice takeoffs and landings there; there's no hangar, fuel, or anything else.  There was, however, a cell tower, which was great because I got full bars of 5G on my phone :D I had prepared for not having cell phone access, but it looked like that would not be a problem.

Yay, Google has updated more of the Blogger UI and I can change image sizes again!

The Sacramento Valley Astronomical Society and some of its members have several domes and roll-off sheds set up out there, which is super cool!  There is a bathroom in the main building, but that building is closed due to COVID.  The site is rated at the low end of Bortle 4 on dark-sky maps; the astronomy club members called it Bortle 3.5.

As soon as I arrived, I immediately got to chatting with the other folks who were there, and learned that everyone in attendance would be doing astrophotography that weekend.  How fun!  I had hoped for a few looks through people's Dobsonians, but oh well.  


I started getting set up, and the MyT was built in no time.  Another club member there had recently purchased a MyT, but wouldn't be getting it for a while, so I showed off all the cool features.  One awesome hardware feature about the mount is that it screws onto the Helium tripod with just one large bolt, so if you're really off on polar alignment, you can rotate the entire mount without having to shift the tripod (which is difficult and dangerous when it's fully loaded, plus you lose your leveling).    At home, I've been running my 8-inch Celestron Schmidt-Cassegrain on it, but with so few hours of darkness, I decided to bring my faster (f/5 vs f/6.3) Takahashi FSQ-106N refractor instead to do some larger summertime targets.  I brought along my ZWO ASI1600MM Pro camera, ZWO 2-inch 7-position electronic filter wheel, and my Orion 50mm mini guide scope with my QHY5 camera that I leave attached to it because it's in perfect focus.  The Takahashi has a Robofocus electronic focuser on it, although I didn't have focus offsets for my filters programmed for it yet.  (Something I can do during twilight).  

In addition to the MyT, I like to have little side projects to work on when I go out to dark sites to take advantage of the dark skies (or, sometimes, to get "consolation prize" data if the main rig doesn't work!).  I brought my Sky-Watcher Star Adventurer camera-lens tracker mount, and my ZWO ASI294MC Pro with my Nikon 50-200mm lens that I've been running on my Celestron AVX mount at home the last couple weeks.  Pairing the 294 with a camera lens is like having an astro-modified DSLR that is also cooled.  :D I've updated the layout of the rig since I originally wrote about it back in January; I've swapped out the filter wheel for my Orion SkyGlow light pollution filter (one that's meant to attach to a Schmidt-Cassegrain that my uncle gave me a while back; I'm not sure it's meant for photography, but it's working out fine so far), and I swapped out the 300mm Nikon lens for my 50-200mm Nikon lens, which has a lot less chromatic aberration and field curvature.  

Also, I have a guide scope attached to it now, woo hoo!

In addition to all that, I also set up my Nikon D5300 DSLR on a little tripod and took an all-night timelapse.

Shot from my timelapse; I forgot to get pictures of my setup!

To polar align the MyT before I ran the re-calibration of the T-point model in TheSkyX, I opened up SharpCap and ran its polar alignment routine after finding a bright star by hand and using it for focus.  (I keep a separate Celestron red dot finder aligned for each one of my telescopes to make this process much easier).  After I polar-aligned, I ran the automated re-calibration routine on about 20 stars, and then used TheSkyX's Accurate Polar Alignment using Arcturus.  Much to my delight, SharpCap and TSX agreed perfectly on polar alignment!  This was quite exciting.  I got all this done during the long summer twilight.

Next, I calibrated the autoguiding software PHD2, and got my sequence created in Sequence Generator Pro.  Oftentimes when I'm at a dark site, I try to squeeze in as many targets as I can, getting enough data on them to have a reasonable image, but never enough for a great image.  So I decided to focus on only one target this weekend: the Pelican Nebula.  Located up in Cygnus right next door to the North America Nebula, it's a gorgeous region of gas and dust with a lot of really cool structures.  The two nights were really short due to the summer solstice -- only about 5 hours of astronomical darkness each.  

PHD finished calibrating, and I connected the camera, mount, focuser, and filter wheel in Sequence Generator Pro, and hit the "Run Sequence" button.  And everything ran perfectly!  

This is the first time I've run a mobile setup and everything worked the first time.  GUYS THIS IS BIG NEWS!!  And I mean everything.  Got the mount built, didn't forget any parts or adapters, all my devices connected on the first try, polar alignment and alignment were easy, PHD calibrated with no issue, autofocus ran perfectly, filters changed like they should, plate solving worked, and the sequence started itself and ran with no issue.  If you spend any amount of time dealing with hardware or software in your life, then you know just how rare an occurrence this is!!  But it hasn't come without many, many nights of blood, sweat, and tears!  You'll notice that this was night #365 since I started doing observational astronomy; it has taken a lot of iterations, problem-solving, fine-tuning, and experience to get to this point.  But boy is it paying off now!!

The sky

With the main scope running smoothly, I took a moment to check out the skies.  It was really quite dark!  I haven't seen skies that dark since last year's Texas Star Party, in May 2019.  There was quite a bit of light to the southwest from Sacramento, and a little bit to the northeast from Reno, but the southeast and northwest skies looked great.  Clouds were dark in those sections, and I spotted M51 just off the handle of the Big Dipper naked-eye again, like I was able to in West Virginia.  

The Milky Way glittered across the eastern sky, with the Cygnus region looking particularly dazzling.  Toward midnight, Saturn and Jupiter burned brightly in the southeast, with Mars poking up from behind the trees.  The Moon was new that weekend, so the skies remained dark all night.

My other DSLR, my Nikon D3100, was busy at home doing a several-week-long timelapse of my peace lily blooming, otherwise I would have brought it along with my 35mm f/2 lens to get more Milky Way shots.  Oh well!

A little outreach

One of the other astronomers out there that night, a Navy vet, invited up some young women he knew, three sisters, to check out the dark skies and hang out with us for a while.  One was in college, and the other two in high school, I think.  I talked to them for quite a while about all things astronomy; how my astrophotography rig worked, some cool asterisms like the Teapot in Sagittarius, some NASA missions like Kepler and Hubble and what they have given us; all kinds of stuff.  They were really interested, and we had a great time.  I had brought along my handheld binoculars, which they passed around to scan through the Milky Way and see the Galilean moons of Jupiter.  I gave them my contact info to chat more.  It was a great time!

The second rig

Since everything was running smoothly on the main rig, I eventually turned my attention to the Sky-Watcher Star Adventurer, ZWO ASI294MC Pro, and Nikon camera lens rig.  I have been having some trouble with the red dot finder for this rig since the battery doesn't sit well inside its housing, so I had to point it blindly at the intended target: the Cygnus Loop, or Veil Nebula.  I've been trying for quite a while to get the whole thing in one shot to come out well, but don't really have a good enough camera lens for it.  But I figured I'd give it a try with this rig.  The Veil was difficult to see in a single frame, and with the wide field of view I couldn't really tell where I was pointing, so I needed the help of technology to get me on target.  The Star Adventurer tracks but doesn't have go-to, so I kind of had to do the centering process by hand: I took a 10s image, uploaded it to (I couldn't figure out how to use PlateSolve2 separately from inside a sequence in Sequence Generator Pro) (I tethered my laptop to my phone's 5G connection), waited a few minutes for it to plate solve, look at the superimposed image on a sky map on the Worldwide Telescope website, and then guesstimate re-positioning the camera and take another image.  I iterated on this process for a while, but just couldn't quite land on it.  

End of the first night

While all the rest of this was happening, I found some time at around 1 AM to finally set up my tent.  I didn't bring my canopy on this short of a trip, so I set up on the west side of the main observatory building so that I could have shade from the morning sun and be able to sleep in for a while.  I wound up chatting with people all night and didn't go to bed until dawn was creeping in at 4 AM!  It was somewhere in the mid to upper 50s in temperature, so I slept pretty well inside my down sleeping bag on my air mattress.  I have a Coleman dark tent that helps block a lot of sunlight and heat, so I was able to sleep in until 10 AM, thanks also to my sleeping mask and earplugs.

Night #2

Most of the folks went home, but a couple stuck around for a second night.  Being a student is a great time to do astronomy because I don't have to be at work or work specific hours, so getting home whenever on Monday was no big deal.  

I spent the day walking the airstrip, running daytime timelapses, reading my friend Sabrina's upcoming book, and moving my chair from shady spot to shady spot as the day wore on. The forecast promised another clear night, with even fewer clouds than we had the night before.  

As dinnertime approached, I pulled out my camp stove and grilled some of the bratwurst I had brought along, which was an excellent life choice.  I set up the grill in the shade of one of the trailers there, which worked out great.  

Summertime is great and all, but the long days and short nights make it hard to be patient for darkness!  But darkness finally did fall, and my main scope again started up without issue.  I had some time to squeeze in some hydrogen-alpha and oxygen-III images as well as the LRGB I was doing since everything ran so smoothly.  

Over on the Star Adventurer, I had spent some time during the day figuring out what to do about my mostly-broken red dot finder, and wound up jury-rigging a finder that attaches to my DSLR's camera shoe into the Synta-type dovetail bracket on top of the ZWO clamp, which was close enough to at least give me some indication of where it was pointing.  Between the finder and plate-solving in again, I finally landed the camera on the Veil Nebula and started acquiring images.  I had roughly polar aligned the Star Adventurer using the polar scope, but since I had the ZWO on it this time rather than my DSLR, I was finally able to use SharpCap to fine-tune the polar alignment.  Even with that though, it's kind of a wobbly mount, so I was only able to get reliable exposures at 60s exposure time at 200mm of focal length.  Oh well -- I was able to get a couple hundred of them though, which should help in getting the target to come out in processing.

After chatting some more with the remaining people, I got myself to bed at 1 AM this time so I could get home in enough time on Monday to hopefully get a little work done.  I let the scopes continue to run the rest of the night.


After making it home before noon on Monday morning, my brain was too fizzled to work on school things, so I processed the Pelican Nebula data instead!  The data looked really good, so I tried a couple different things for processing.  

Date: 20, 21 June 2020
Location: Blue Canyon Nyack Airport, CA (Sacremento Valley AS dark site)
Object: IC 5070 Pelican Nebula 
Attempt: 3
Camera: ZWO ASI1600MM Pro
Telescope: Takahashi FSQ-106N
Accessories: ZWO 7-position 2-inch filter wheel, RoboFocus, Astronomik CLS-CCD 2-inch filter, 
Astronomik RGB Type 2c 2-inch filters, Chroma 3nm Ha & OIII 50mm filters
Mount: Paramount MyT
Guide scope: Orion 50mm mini-guider
Guide camera: QHY5
Subframes: L: 26x300s
   R: 17x180s
   G: 13x180s
   B: 11x180s
   Ha: 5x600s
   OIII: 5x600s
   Total: 5h53m
Gain/ISO: 139
Acquisition method: Sequence Generator Pro
Stacking program: PixInsight 1.8.8-5
Post-Processing program: PixInsight 1.8.8-5
Darks: 100 each
Biases: 0
Flats: 0
Temperature: -20C

The narrowband data didn't have a whole lot of subframes, and the luminance channel didn't have quite enough subframes to do really good deconvolution, but overall it came out all right!  I enhanced the red and luminance channels with the Ha, and enhanced the green and blue channels with the OIII.  (Details on how to do this can be found on the Light Vortex tutorial website).  

For fun, I processed just the Ha data as well, and I removed the stars using the Starnet++ plugin.  (The readme file includes installation instructions.  You can also run it outside of PixInsight).  It's quite a dramatic image.

I love the monochrome Ha starless image. It's so cool!  It looks familiar yet alien at the same time.

Over on the Star Adventurer, the Veil Nebula came out okay.  It's probably the best of the times I've attempted it with a camera lens, largely because the ZWO ASI294MC Pro is a lot more sensitive to red (and more sensitive in general) than my DSLR.

Date: 21 June 2020
Location: Blue Canyon Nyack Airport, CA
Object: Veil Nebula
Attempt: 2
Camera: ZWO ASI294MC Pro
Telescope: Nikon 50-200mm lens @ 200mm, f-something
Accessories: Orion SkyGlow filter
Mount: Sky-Watcher Star Adventurer
Guide scope: N/A
Guide camera: N/A
Subframes: 88x60s
   Total: 1h32m
Gain/ISO: 120
Acquisition method: Sequence Generator Pro
Stacking program: PixInsight 1.8.8-5
Post-Processing program: PixInsight 1.8.8-5
Darks: 100
Biases: 0
Flats: 0
Temperature: -20C

I didn't get great detail on the nebulae if you were to look up close, but I did pick up a fair bit of the Pickering region, which was exciting!  Unfortunately, this lens is not really ideal for astrophotography, so my stars are enormous and dominate the image.  Later this year, I'll be purchasing the Samyang or Rokinon 135mm f/2, most likely.  I got to use one on my trip to Chile last year and it was amazing!

The reason I say "f-something" for the focal ratio is because I don't actually know what it is.  My Nikon 50-200mm lens has electronically-controlled aperture than than manually-controlled, so in order to open the aperture, I cut a toothpick into small pieces and inserted them in the groove where the aperture lever is to keep it open.  I initially tested it fully wide open, but there was some pretty significant field curvature, so I took out one of the toothpicks so now it's only half-open.  Also, I've taped down the focuser and the zoom so that they don't move with some gaffer's tape.  It was still in focus both when I got out to the campsite and when I got back!

Imaged here with both toothpicks in, fully opening the aperture.
They're the same height as the lever, so they don't interfere with attaching the camera to the lens bayonet adapter I have on my image train for the ZWO camera.


It was a really, really great weekend!  I was glad to get out of the house for a bit during all this lockdown, we had really nice weather, and I got some great astro images.  My gear worked really well, and I met some great people.  Hopefully I'll be able to go up a couple more times this summer.  The itch to finally get a camper-trailer is getting at me again, if I can find room in my budget, especially since I towed a trailer when I moved out here last summer and partly got over the fear of towing.  We shall see...

I'm really glad I got to do this!  Can't wait for more!