Monday, October 11, 2021

#574 & #575 - October 8 & 9, 2021 - Hidden Hollow Star Party

 After a two-year absence, it was very exciting to return to the Hidden Hollow Star Party!  It's a small star party up at the Warren Rupp Observatory hosted by the Richland Astronomical Society, south of Mansfield, OH.  The weather is usually less than ideal, but it's only a two-hour trip for me, and it's a fun group of people at a nice summer camp location in the woods.  One of the awesome things about Hidden Hollow is their enormous 36-inch Newtonian telescope, "Big Blue."  It's a treat to look through between the clouds!


Because the forecast was not looking promising at all, I decided to only bring one rig.  I recently bought this awesome 3D-printed bracket on Agena Astro for the Rokinon/Samyang 135mm f/2 lens, ZWO EAF focuser, and ZWO ASIAir.  



I mounted it on my Celestron AVX.  Eventually I'd like to get it running on my Sky-Watcher Star Adventurer, but for this trip I wanted slew control, target centering, two-axis guiding, etc.  

What is all on this rig:
- Rokinon 135mm f/2 lens
- Red box: ZWO EAF electronic focuser. It's attached to a belt and notched circle that come with the kit to focus the camera lens.  It works really well actually.
- On top: Orion 50mm guide scope + ZWO ASI120MM-S guide camera, as well as a red dot finder
- On the other side: ZWO ASIair Pro
- On the back: ZWO ASI294MC Pro camera + Starlight Xpress 5-position 2-inch filter wheel.  Inside the filter wheel is an Astronomik L Type 2c luminance filter, Astronomik CLS-CCD light pollution filter, and Optolong L-eXtreme dual-narrowband filter.

Part of my goal for the weekend was to try using the ASIair to control the rig (except for the filter wheel, which is not ZWO and therefore can't be controlled by it).  Unfortunately, while everything connected to the ASIair when I was at home, neither of the cameras wanted to talk to it once I got out to Hidden Hollow.  I had brought along one of my capture laptops (a 2012 Lenovo running Windows 10) just in case, so I used that instead.

Here it is all set up at Hidden Hollow:


Yes it's a bit of a cable mess, but since this isn't (yet) one of my standard rigs, I don't have a cable harness made for it yet.


Friday

I had originally planned on going out on Thursday, but the weather not only looked cloudy but also rainy, so I didn't think anyone would be there.  So I drove up Friday instead.  I brought my awesome little camper along with me.  I forgot to get a picture at Hidden Hollow, but here's another photo:


I drove my car up by where I planned on setting up and got unloaded and the mount built and balanced.  After chit-chatting and greeting lots of people I'd seen in the past there, I finally snagged a few minutes to heat up a couple of bratwurst on the stove in my camper before it got fully dark.  

The forecast called for lots of clouds, but I was hoping to get enough of a northern view to at least get polar aligned so that I would be ready for any opportunity I had the next night to image.  The sky was clear in segments, but they kept covering up the north star.  Finally I got several minutes of clear sky up north to get polar aligned using SharpCap, woot!  It actually cleared out a decent bit, so I decided to try some imaging and get whatever I could get.  By the time I finally got polar aligned, it was about 10:30 PM, so my main target for the weekend, the California Nebula, was up and ready to roll.  The AVX slewed there no problem being controlled by CPWI, but the plate solver wasn't working -- I couldn't get either PlateSolve2 nor ASTAP to work, they both kept coming back with "invalid solve" after only a little bit of searching, not the usual wide search they'll do.  I uploaded an image to astrometry.net to make extra sure that the pixel scale I put in Sequence Generator Pro was right -- 7.07 arcsec -- and it was.  While I was trying to think of what else to do, I went ahead and got PHD2 calibrated for autoguiding, and then more clouds rolled in.  I decided to give up for the night because the clouds were coming in stronger and I was pretty damp from the high humidity.

Saturday

Saturday started out foggy and cloudy, but cleared out later in the day.  I spent the day attending talks on topics from meteorites to "spooky" celestial objects, as well as running around with my two DSLRs doing timelapse videos.  

By mid-afternoon, the forecast had much improved for the night!  I went around exclaiming the good news.

In the Astrospheric app


I got to give a talk in the late afternoon about my trip to Chile in 2019, which was a lot of fun and I got a lot of compliments on it.  (You can see a version of that presentation here).  

After my talk was the raffle drawing, and they had some fun and nice stuff this year.  I put in for a waterproof case and some green laser pointers among other things, and ended up winning a fun Star Trek ornament instead!

Deep Space Nine version of Worf holding his bat'leth


After having another quick bratwurst and some leftover pasta salad I brought along, it was time to get set up for the night.  During twilight, I tried again to get the plate-solver to work, this time connecting my laptop to my cell phone's wifi to make sure that the plate solve catalogs were still downloaded in my OneDrive.  I also shut everything down and rebooted.  Finally, I apparently Googled the right thing because I had a solution in about thirty seconds: untick the "highest accuracy solution" button in PlateSolve2 when doing widefield stuff.  Whoops! Had forgotten that little tweak.  Finally, plate solving worked!  The California Nebula wouldn't be high enough until 10:30 PM or so, so I did a short run on the Andromeda Galaxy as well.  I hit "go" in Sequence Generator Pro about a half hour before astro-darkness and went off to go gleefully look through other people's telescopes.

Saturn and Jupiter were on full display in the early evening, so I looked through a few scopes at them.  Venus and the crescent Moon also made a brilliant display as they set in the west.



I also looked at a few globular clusters and M82 through people's Dobs.  One guy had a white night vision monocular that he had a visual hydrogen-alpha filter attached to.  We took turns looking around the Milky Way -- you could see all of our hydrogen regions!  It was incredible!  All the nebula of the Cygnus region just jumped out, M8 and others in Sagittarius shone brightly, and you could easily see the Heart, Soul, and Elephant Trunk nebulae up north.  It was so cool to see them at 1x magnification on the sky!  Another night vision monocular was on one of the Dobs, and they were looking at M13 I think when I was over there.  I snagged a few pictures!


I couldn't quite get my smart phone camera (Samsung Galaxy Z Flip 3) to center on the eyepiece, but it was really cool anyway.

Looking through Big Blue

Of course, you can't go to Hidden Hollow and not look through the 36-inch, 9-meter focal length monstrosity that is Big Blue!  In order to reach the eyepiece, they use a scissor lift, which definitely takes some skill to drive around the dome.  They have a computer and monitor up on the lift that is connected to a system on the telescope so that you can give it one alignment point and then slew the telescope to your target by hand with a distance counter on the monitor showing you how much farther N-S and E-W you have to go, and it's quite accurate.  They also have a wireless remote up there to rotate the dome.  It's a really awesome setup.  But it is difficult to move the lift around the scope, and there is only a limited set of the sky you can look at because of the length of the telescope, how far the dome slit opens, whether you can maneuver the lift around, and the eyepiece location -- the scope is equatorially mounted, so the eyepiece rolls around out of reach in some parts of the sky.  Most of the evening was spent looking at Jupiter and Saturn, which displayed an incredible amount of detail at that insane focal length and aperture.  I could count more cloud bands on Jupiter than I think I'd ever seen before, and I could spot a small storm.  Saturn had something like five moons on display for us -- Rhea, Iapetus, Enceladus, Tethys, and Dione, with Hyperion on the edge of the FOV.  

After everyone got their fill of the planets, they tried to move the scope to M27, the Dumbbell Nebula, but it turned out to be blocked by the top of the slit, which I guess normally opens further but wasn't that night for some reason.  So I suggested we try the Ring Nebula instead, but that turned out to be too far west -- the eyepiece rolled over the top, where we couldn't reach it.  I was up on the lift with one of the club members who was operating the scope, so I hurriedly scrolled through my SkySafari list to see what would work, and globular cluster M2 was not far from Jupiter, which we knew we could reach.  Globular clusters are awesome in big ol' telescopes.  I got to slew the scope and rotate the dome to get on target, which was fun!  I found it in the finderscope, and then in the eyepiece, and it was awesome to look at.  The club member (couldn't tell who it was in the dark) maneuvered the scissor lift, which was a tough job!  It took us a while to get in position.  It was a fun time.  All the while, my telescope rig was running on its own, so I didn't have to worry anymore about getting sidetracked and missing a filter change or target change or meridian flip.  Soooo nice :D

Transparency had degraded, and everything was getting soaking wet, so most of the visual observers on the pad were packing up for the night.  I was chit-chatting with a few folks, and felt like it must have been after 1 AM or something.  But no, by the time I got to my camper to get ready for bed, it was only five minutes before midnight!  I went to bed and got a nice long night's sleep.

Death of the D3100

This weekend finally saw the end of my Nikon D3100, my first DSLR, as well as its kit 18-55mm lens.  The lens started its death spiral about a year ish ago when I accidentally knocked over my other DSLR, my Nikon D5300, during a timelapse in my backyard in California, which knocked the front section of the lens out of alignment, but I was able to get it back into place.  This time around, something must have broken recently because I couldn't get it back into place, and I couldn't get it to sit straight.  Almost at the same time, I was looking through the timelapse images I'd just taken with the D3100 (which earlier hadn't turned on, but eventually did), and the shutter was only opening partway for the first couple frames, and then didn't open at all after that.  I tried to lift it with my finger, but only the front plastic part was going up, not the rubbery second layer.  I'm not sure how they're normally attached to each other, but I think there's something wrong with the little hinges in there.  

The D3100 has been a real workhorse.  I bought it in July 2014, almost exactly one year before I got my first telescope.  It's traveled with me on many hikes and a few backpacking trips, always hanging around my neck or shoulder.  It was my first astro camera, capturing my very first astrophotos through my Celestron 8-inch Schmidt-Cassegrain on the NexStar alt-az mount of Saturn and the Lagoon Nebula, and has come along as a timelapse and widefield camera to star parties and astro weekends from Washington and California to Texas and Wyoming to Ohio and West Virginia.  It captured wide shots of both the 2017 solar eclipse in Wyoming and the 2019 solar eclipse in Chile.  Over the last seven years, it has captured nearly 130,000 images, according to the shutter count, which is right around the mean lifetime for the D3100.  My second DSLR, bought in 2016, already has over 300,000 shutter actuations!  

It looks like I might be able to replace the shutter myself, or send it to Nikon for repair.  I might just do that.  My D5300 has been having trouble with exposure metering, so it'd be good to have a DSLR that can still do that.  However, I had already been kicking around the idea of getting a new DSLR to replace the D3100 that has the computer control capability that the D5300 has...we shall see.  

Unfortunately on the lens front, they don't make that 18-55mm kit lens anymore.  There's a VR (vibration reduction) version that technically works with my D5300, but the VR part isn't compatible.  I found one of the same model as my kit lens on the used camera gear retailer KEH, but they just emailed me and said that it's not actually in stock after all. :(  That lens I definitely need to find a replacement for ASAP!  I'm open to suggestions...

Results

The sequence ran until about 4:30 AM, when the clouds and fog started rolling in in earnest, according to an all-night timelapse I had set up.  I got 44x300s images on the California Nebula, and 22x300s on M31.  Not too shabby!  I also got nine timelapse videos that I'll be putting together into a single video with some music.

The California Nebula came out all right.  Using a narrowband filter with a fast f/2 optic is problematic since the light gets shifted a bit off-band by the optics (and stopping down the lens doesn't help since you're not changing the optics), which results in lower transmission.  I was surprised at first to barely be able to see the nebula in subframes (it jumped out using an H-alpha filter with my ZWO ASI1600MM Pro on my C8 last year), but then I remembered this fact.  It came out all right anyway, if a bit noisy!  And since I forgot to stop the lens down to like f/2.8 or so, the coma around the edges was pretty bad.  But I did get some nice color!

Date: 9 October 2021
Location: Hidden Hollow Star Party, OH
Object: California Nebula
Attempt: 2
Camera: ZWO ASI1294MC Pro
Telescope: Rokinon 135mm f/2 lens @ f/2
Accessories: ZWO EAF focuser, Optolong L-eXtreme 2" filter
Mount: Celestron AVX
Guide scope: Orion 50mm guidescope
Guide camera: ZWO ASI120MM-S
Subframes: 38x300s (3h10m)
Gain/ISO: 120
Acquisition method: Sequence Generator Pro
Stacking program: PixInsight 1.8.8-8
Post-Processing program: PixInsight 1.8.8-8
Darks: 75
Flats: 25
Temperature: -15C


The M31 image had a few problems -- one was that I rapid-cooled the 294, thinking I had time for the frost spot to go away, but it stuck around for quite a while.  Normally, to keep the frost spot from forming, I cool it by 5 degrees C over 5 minutes at a time.  This works quite well, but I haven't figured out how to script it yet, so I have to sit there and do it.  (And yes, I have recharged the dessicant).  But here it is anyway:
Date: 9 October 2021
Location: Hidden Hollow Star Party, OH
Object: M31 Andromeda Galaxy
Attempt: 21
Camera: ZWO ASI1294MC Pro
Telescope: Rokinon 135mm f/2 lens @ f/2
Accessories: ZWO EAF focuser, Astronomik L Type 2c 2" filter
Mount: Celestron AVX
Guide scope: Orion 50mm guidescope
Guide camera: ZWO ASI120MM-S
Subframes: 22x300s (1h50m)
Gain/ISO: 120
Acquisition method: Sequence Generator Pro
Stacking program: PixInsight 1.8.8-8
Post-Processing program: PixInsight 1.8.8-8
Darks: 75
Flats: 25
Temperature: -15C


Despite the iffy forecast, Saturday night was decently clear and a fun night.  The whole weekend was a really nice time -- getting to see quite a few people I haven't seen in a while and getting to give a talk, and just enjoying some fresh air and camping and stargazing.  It was a nice weekend, and I'm looking forward to next year!









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