#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!

Previous post: #510 - Saturday, April 17, 2021 - New Off-Axis Guide Cam!

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#510 - Saturday, April 17, 2021 - New Off-Axis Guide Cam!

On long-focal-length telescopes like Schmidt-Cassegrains (and especially Schmidt-Cassegrains, with their floppy mirrors), off-axis guiding can provide better guiding than a guide scope.  I've been using an off-axis guider with my C8 since 2018, and despite some troubles, it has still largely been a better solution than when I was using a guide scope.

I initially paired it with my QHY5 (the original red puck), but found it to be not sensitive enough to pick up guide stars, even at f/6.3 (1280mm).  I picked up the more-sensitive QHY5L-II CMOS guide camera not long after, which typically gets just barely enough signal-to-noise ratio to hold onto a guide star on my setup.  Of course, it performs better under dark skies, but any drop in transparency, and I'm barely holding onto a star, especially in the spring when the density of stars around out-of-galactic-plane targets tends to be a lot lower.

A good night of guiding in February...just enough SNR to hold onto the star.

While the QHY5L-II worked more often than not for me, I started growing tired of losing images because of lost guide stars, and losing hours of the night while Sequence Generator Pro made attempts to recover.  So I've been kicking around the idea of getting a Lodestar, which is a tiny CCD camera made by Starlight Xpress with big juicy pixels and high sensitivity.  The current iteration of this camera is the Lodestar Pro, which was 8.6 micron pixels and 77% quantum efficiency.  Unfortunately, it costs almost $600, which is a bit hard for me to justify when my system mostly works. 

However, I recently came across a used original-model Lodestar being sold by an area astronomy club member, so I pounced on it (along with an enormous 315mm electroluminescent flat panel and a network-enabled sky-quality meter).  The older version of the Lodestar has 8.4 micron pixels and 65% quantum efficiency, so not a huge difference technically (several other specs are the same as well), although the read noise is lower in the new version.  

The first thing to do was to make sure it would talk to my laptop.  I installed the ASCOM driver for it, connected it to SharpCap, and it started taking frames right away.  Woot!  Shining light on it showed a response.

Focusing the Guide Camera

The next challenge was getting it on the off-axis guider.  This is an event.  Getting it focused is not easy.  You have the three-fold problem of not being in focus, not having a star in the field bright enough to show up when very unfocused, and it's very hard to tell where the OAG is looking to get a star placed in it.

The first night I tried it, Wednesday, didn't go well at all.  There were low clouds running across the sky, and once I got a bright star in my main camera and started slewing around to see if it would show up as a big unfocused blob in the guide camera, a cloud would inevitably cover the star.  I gave up that night and went to bed.

Saturday night was much better, and had better transparency.  Bonus points, the waxing crescent Moon was high enough above my lemon tree to see with my C8.  A super-bright object is a lot easier to land in the guide camera because you can see it coming from off the edge.  I slewed the scope over to the Moon, centered and synced it in the main camera, and then slewed above and below the main camera image to see where it would show up in my guide camera.  Pretty quickly I could start to see the guide camera image lighting up, so I adjusted the exposure time down for seeing the Moon's surface, and got the guide camera roughly focused.  I also created a field-of-view indicator element in TheSkyX where the Moon was in my guide camera compared to the main camera so that I could more easily land a star inside of it.

The center rectangle is the main camera; the smaller one above is my old guide camera; the rectangles above and below are the E and W side of the pier positions of the guide camera, respectively.

Next, I slewed the main camera to Regulus and centered it, synced the mount to it (so that it would be in the correct position with respect to my camera FOVs on the map), and then slewed the mount so that Regulus would show up inside the guide camera box.  And bang, there it was!  Now time to critically-focus.

Now, I use two different brands of filters: Astronomik CLS-CCD & RGB, and Chroma narrowband filters.  They have different thicknesses, and thus adjust the main camera's exact focus point a bit.  ("A bit" on my PrimaLuce Esatto focuser is still like 20,000 steps).  So to set the guide camera position so that it's mostly in focus for both focus points of the two sets of filters, I take the CLS-CCD filter's in-focus point and the H-alpha filter's focus point and split the difference.  I set the focuser there in the middle of the two, and then moved the camera in and out until the star was as small as it would get.  Now, since we're so far off-axis and this is a Schmidt-Cassegrain, the star shapes are pretttttyyyy yucky, so "in focus" is hard to determine.  But I got it about as small as it would appear in the camera, and called it good.  

Unfortunately, that focus point has the Lodestar just barely inside the tube!  I put on a C-mount extension tube, but it has a lip on it that won't let me insert it far enough to get the camera in focus.  So I need to hunt down an extension tube that doesn't have a lip.  We'll see if I can find one.  

Left to right: ZWO ASI1600MM Pro, ZWO electronic filter wheel, 21mm spacer, Lumicon off-axis guider + Lodestar, PrimaLuce Lab Esatto focuser

Time to Test

Next, I needed to re-calibrate guiding in PHD2 for the new camera.  I slewed the scope to somewhere roughly due East and about 50 degrees up the sky and started looping 8s exposures.  Now, I had already discovered during initial connection testing that this Lodestar has a lot of hot pixels.  And because of the way the camera is read out, some kind of interlacing to increase the speed, the hot pixels really look rather star-like.  I did try to take a dark library in PHD, but they never work for me -- they always over-subtract, and I end up with a bright gray image with black specs where the noise pixels used to be.  However, this is one place where the gross shape of the stars off-axis in a Schmidt-Cassegrain actually works out in my favor: they're way bigger than the hot pixels.  After some trial and error, I set the HFD (half-flux diameter) minimum value in the settings (brain icon) to be 3 pixels, and this did the trick.  PHD grabbed what appeared to be dim, blobby stars rather than the star-like noise pixels.  

The hot pixels really mess with PHD's auto-stretching algorithm, so I could barely even see the guide star.  However, your ability to see it isn't what matters -- only PHD's ability to see it.  This is given by the SNR (signal-to-noise ratio) reading.  The higher the value, the better (until it says "SAT" which means you're saturated, which diminishes PHD's ability to calculate the centroid of the star).  While I have been used to values between 5-20 on the QHY5L-II, the Lodestar showed values of 50-90, even in star-poor galaxy regions!

This was very exciting and very promising indeed.  So I got the main camera cooled and started running the sequence for the C8 for that night, which consisted of planetary nebula Abell 31, planetary nebula Sh2-313 (Abell 35), galaxy NGC 5248, and M16 Eagle Nebula.  Abell 31 had some initial trouble with the guide star wandering off, but it was almost behind the tree anyway, so I had SGP just advance to the next target.  Despite Sh2-313 being really low in the south for me, the PHD2 screenshot above was taken there, showing good SNR even through muddy and light-polluted skies.

The rest of the night was quite successful -- all of my targets ran and got a lot of subframes, and it looks like the night finished strong with M16, which is in an area with plentiful bright stars to choose from.

0.55 arcsec RMS guiding is pretttty good :D  And so is that SNR and star profile!

Single luminance (CLS-CCD) subframe, 300s, M16 Eagle Nebula, on the C8

Previous post: #457 - Monday, December 21, 2020 - Conjunction Junction

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#457 - Monday, December 21, 2020 - Conjunction Junction

 It was one of the most-talked-about astronomical events of the year -- the Great Conjunction of Jupiter and Saturn!  The two heavenly bodies appear close to each other from our perspective about every 20 years, but are not usually close enough to be a big deal.  The last time, in May 2000, they were 68.9 acrmins apart, or a bit more than two full Moons side-by-side.  This year, however, they would draw as near as 6 arcminutes apart -- nearly on top of each other.  The last time they were this close was back in 1623, in the days of Galileo; however, the two planets were close to the Sun, so it is likely that nobody witnessed it.  Before that, there was the Great Conjunction of 1226, in the time of Genghis Khan, which was visible at night.  Luckily for us young folk, the next close pass of Jupiter and Saturn will occur in only 2080, which some of us may live to see.  (For more info, see this article in Scientific American).

I had put the event on my calendar some time ago, probably back in 2019, and set reminders for myself so I could prep.  Of course, with all the chatter on the Internet, how could I forget?  I started working up a plan back in the fall, and in the days leading up to closest approach, I did some test runs.

About a week before the actual night of closest approach, I saw on SkySafari that the two planets were close enough to catch in my refractor, and since it's positioned in such a way that I could see the two shortly after sunset before they disappeared behind the tree, I nabbed a video on my one-shot color ZWO ASI294MC Pro camera and produced an image.

Date: 15 December 2020

UTC: 16 December 2020 01:34

Location: East Bay area backyard, CA

Object: Jupiter & Saturn, near conjunction

Camera: ZWO ASI1294MC Pro

Telescope: Takahashi FSQ-106N

Accessories: ZWO EAF focuser, Astronomik CLS-CCD 1.25-inch filter

Mount: iOptron CEM40

Exposure: 15ms (Jupiter), 150ms (Saturn)

ISO/Gain: 120

Acquisition method: SharpCap Pro

Stacking program: PIPP

Processing program: Photoshop CC 2021

I couldn't get AutoStakkert to align the frames because of the two separated targets, so I just had PIPP (Planetary Image Pre-Processor) sort them by goodness and I pulled the best frame from each of the two videos (one for Jupiter and one for Saturn, because of the two different exposure times needed) and combined them in Photoshop.  So it's a little blurry, but still cool to see them so close!

Gear

Because they were only going to be six arcminutes apart, I was going to be able to throw a lot of magnification at them and get a nice shot.  I decided to use my Celestron 8-inch Schmidt-Cassegrain, which has excellent performance on planets.  It currently is seated on my Paramount MyT, and I've been using it for deep-sky imaging all year.  Unfortunately, the Paramount was on the wrong side of my backyard to be able to see the conjunction, which was low in the western sky -- my enormous lemon tree blocks the view.  So I went old-school and pulled my Celestron NexStar SE alt-az mount out of the garage, which I primarily use for outreach (back when we could do that in-person) and for planetary imaging that I can't reach from my backyard.  The nice thing with using an alt-az mount for this transient events is that I don't have to polar align it or even have a decent alignment model -- I can just plop it down, point it at a planet, and say "track this," and it does a decent-enough job for the short exposures of planetary imaging.  

For the camera, I decided to use my monochrome CMOS camera, my ZWO ASI1600MM Pro.  I always get better results on it, and I can get higher-resolution images from it because a) the pixels are smaller and b) every pixel is used instead of interpolating 2x2 quads of pixels to produce color images the way one-shot cameras do.  The downside is that I have to be quick on the draw, changing filters and nabbing frames as fast as possible to get all three colors before Jupiter rotates appreciably, which is a timespan of about 90 seconds.  Luckily, I'm quite practiced at it.  I used my Astronomik RGB filters in my ZWO electronic filter wheel, and I removed the focal reducer for maximum resolution and magnification.  

The laptop I typically use with my primary rig is an old Lenovo from 2012, named Feynman, that I refurbed with a solid-state hard drive.  It performs quite well, but only has USB 2.0, which limits my frame rate to about 1 fps full-frame.  My other data acquisition machine is my Microsoft Surface 3 tablet, named Messier, which is also getting on in years and has been slowing down significantly, even after an operating system clean re-install.  It has USB 3.0, but I knew I wouldn't be able to livestream from it, which I was planning to do with Explore Alliance.  So I decided to spin up my performance laptop, named Cherenkov, which is an MSI I bought myself for Christmas in 2018 for grad school use and star party on-site image processing use.  I moved my table over, and brought out a light so I could be seen on camera, as well as my webcam and mic (the built-in ones on this laptop are terrible).  I got SharpCap Pro and all my camera and filter wheel drivers installed.

Test Drive

I tested out the whole setup on December 18th.  After a couple of issues with not having all the drivers I needed installed, I got everything rolling, and got my Streamlabs OBS settings set up how I wanted.  Once it finally got dark enough to spot them, I got the mount aligned on them and started imaging.  Everything went pretty smoothly -- I have a lot of experience in getting set up now!  

Jupiter and Saturn were already close enough to image at prime focus, without the focal reducer!  I had some trouble processing the images though still.  I even used PIPP to do some pre-alignment, but still couldn't quite get it to go.  I hoped that it would be easier once they were closer together.

The Great Conjunction

The night finally arrived!  I had actually delayed by travel home for Christmas when I bought my plane ticket back in October so I could be at my house for the conjunction.  Dedication :D

There were some clouds in the west before sunset, and I was getting worried.  But they were kind of patchy, so I hoped to at least manage some shots through them.  Fortunately, they cleared out after sunset!  Then it was just a waiting game for Jupiter to become visible so I could align the mount.  I had moved it around since the test drive, so I had to re-align it.  

Since I had put the C8 back on my Paramount for deep-sky imaging, it was out of focus, which would make landing on the planets more difficult and waste precious time.  So I picked up an moved the mount so that I could see the Moon and use it for focusing.  Then I moved it back over to the spot for the conjunction.

Finally, after peeling my eyes, Jupiter finally appeared a half hour after sunset.  Showtime!  I got the scope pointed at it and aligned, got them on the screen, and did some fine focusing.  I immediately started taking videos as soon as everything was ready -- I wasn't going to have much time before they sank below the fence line.  I also streamed the camera's view live on the Explore Alliance show for the conjunction.  

I had to move the mount back a few times to keep the planets in the scope's view -- one downside of such a large aperture is that even though the finderscope was still well above the fence, half the telescope aperture was below it, and the planets were dimming significantly.  After getting a good round of RGB exposures, I took a luminance exposure to get Jupiter's moons, and then removed the camera.  I had promised myself that I would look at them visually, and I am so glad I did!  I threw on the star diagonal and 25mm Plossl eyepiece, and the two planets looked awesome side-by-side. It was super cool to see them so close together.

The Result

I finally managed to get AutoStakkert to play ball by having it only worry about the planet that had the right exposure (since I had to take two different exposure times for their large difference in brightness), and I got the red, green, and blue channels stacked for both Jupiter and Saturn.  I used RegiStax to apply the wavelet deconvolution to sharpen them up, and then I used PixInsight's FFTRegistration script to align each set of RGB frames and combine them into color images.  Then I brought them over to Photoshop to manually composite the Jupiter, Saturn, and Jupiter's moons exposures into a single image, and did some color correction and adjustments.  The final result came out quite nicely, despite how low they were in the sky!

Date: 21 December 2020

UTC: 22 December 2020 02:30

Location: East Bay area backyard, CA

Object: Jupiter-Saturn Great Conjunction

Camera: ZWO ASI1600MM Pro

Telescope: Celestron C8

Accessories: ZWO 2-inch 7-position EFW, Astronomik CLS-CCD & RGB Type 2c 2-inch filters

Mount: Celestron NexStar SE

Frames: Best 20% of 250 each

FPS: 15

Exposure: R: Jupiter: 75ms, Saturn: 150ms

  G: Jupiter: 75ms, Saturn: 150ms

  B: Jupiter: 125ms, Saturn: 300ms

  Moons: CLS-CCD filter, 100ms

ISO/Gain: 139

Acquisition method: SharpCap Pro

Stacking program: AutoStakkert 3.0.14

Processing program: RegiStax 6, PixInsight 1.8.8-7, Photoshop CC 2021

You can only see three of Jupiter's Galilean moons because Ganymede was in transit (but with our current angle to Jupiter, there was no shadow until after Jupiter was too low to see).  

My prep work and practice paid off!  I'm very pleased with the image I got, and I even got to livestream it.  What a night!

Other Fun

Not only was December 21st the night of the Great Conjunction, it was also the night of the first-quarter Moon, and only an hour or two after the conjunction, the Lunar X and Lunar V would both be visible!  The last time I shot the Lunar X was accidentally when I took my very first videos of the Moon using my DSLR on the very same C8 back in May 2016, and I had never imaged the Lunar V.  So I took advantage of not having the focal reducer in place and took some nice Moon shots.  I did move the telescope back over to the Paramount though, since it was going to be a clear night and I wanted to squeeze in another night of deep-sky imaging.  The seeing wasn't great, but they came out all right.

Date: 21 December 2020

UTC: 22 December 2020 02:18

Location: East Bay area backyard, CA

Object: Moon

Attempt: 67

Camera: ZWO ASI1600MM Pro

Telescope: Celestron C8

Accessories: ZWO 2-inch 7-position EFW, Astronomik R Type 2c 2-inch filter

Mount: Paramount MyT

Frames: Best 20% of 1,000

FPS: 33

Exposure: 20 ms

ISO/Gain: 0

Acquisition method: SharpCap Pro

Stacking program: AutoStakkert 3.0.14

Processing program: RegiStax 6, Photoshop CC 2021

I even nabbed RGB videos of Mars before I put the focal reducer, off-axis guider, and focuser back on, although I haven't gotten around to processing it yet.

What a fun-filled night!

#510 - Saturday, April 17, 2021 - New Off-Axis Guide Cam!

Previous post: #403 - Sunday, October 11, 2020 - Planet-a-palooza!

Table of Contents

#403 - Sunday, October 11, 2020 - Planet-a-palooza!

 We haven't had a whole lot of clear nights here lately, so I have been trying to squeeze in some partial-nights of imaging when I can.  Unfortunately, the right ascension motor on my Celestron CGE Pro mount, the one I use for my science rig (for taking variable star and exoplanet transit data), has died.  So there will be a bit of a break in the science-data-taking while I get another rig set up.  After a talk I gave recently for the AAVSO 2020 webinar series, member Gary Walker, one of the leaders of the Instrumentation & Equipment section, offered to pass along to me a Celestron AVX mount as well as an older QSI 583 CCD camera.  I'm very excited to receive both!  The QSI camera should perform much better than the Orion Deep Space Monochrome Imager II I've been using on the science rig.  My Celestron AVX can't quite handle the 8" Newtonian I use on the science rig, but I think I got one that's on the lower end of their manufacturing tolerance -- I've seen people do better with their AVX's.  So I'm hoping perhaps his will perform better and I can use the Newt with it.  Regardless, it will be put to good use -- I've always got some kind of plan rolling around in my mind. :D

Meanwhile, the plethora of planets in the evening sky has been taunting me for weeks!  Normally I would set up my outreach rig and do some planetary imaging -- my 8" Celestron Schmidt-Cassegrain on my Celestron NexStar SE mount.  However, since I gave up on using my 11" SCT, I've been using the 8" all summer, and plan to keep it on my main imaging rig throughout the winter.  So I decided to spend a few evenings on the planets, and I swapped out my deep sky optics train for the planetary one.

For deep sky imaging, I use a 0.63x focal reducer/field flattener on the C8 to decrease the focal ratio from f/10 to f/6.3 (making the scope "faster") while widening the field of view.  The reducer puts me at an effective focal length of 1280mm, which gives me a large enough field of view to image most nebulae (except for the very largest ones), but not so large that I can't do galaxies and planetary nebulae.  However, for getting the best resolution on solar system objects, you want a looooooong focal length -- as much magnification as you can get away with given the aperture of your scope and the seeing conditions.  I previously used a Celestron 2x Barlow, but always got a bit of chromatic aberration from it, so I finally upgraded to a Baader Hyperion 2.25x earlier this year, and finally gave myself a chance to use it.  So I swapped out the focal reducer for the Barlow, and I also took off my PrimaLuce Esatto focuser because the last time I tried this, I had some trouble with it being too close to the scope and hitting the focuser knob.  

From the scope: SCT-thread to 2" adapter, 2" to 1.25" adapter, Baader Hyperion 2.25x Barlow, ZWO electronic filter wheel, ZWO ASI1600MM Pro

First up: Jupiter

After weeks of wildfire smoke, the air quality app on my phone reported an AQI (air quality index) of less than 10 -- a huge change from the 100-200 we've been having!  And on the few nights it hasn't been smoky, there's been clouds and haze.  But it was crystal clear, finally!  Now I just had to hope that the seeing was good.

The westernmost planet in the lineup is Jupiter, so I started there.  I got several videos on it using SharpCap and rotating through my red, green, and blue filters before it slipped behind my lemon tree, and the seeing was decent, and the image came out all right!  Bonus points: the Great Red Spot was prominently featured, and Europa was just to the side, about to pass behind the planet.

Date: 11 October 2020

UTC: 12 October 2020 02:14

Location: East Bay area backyard, CA

Object: Jupiter (and Europa)

Attempt: 26

Camera: ZWO ASI1600MM Pro

Telescope: Celestron C8

Accessories: Baader Hyperion 2.25x Barlow, ZWO 2-inch 7-position EFW, Astronomik RGB Type 2c 2-inch filters

Mount: Paramount MyT

Frames: Best 20% of 1-2,000

FPS: 13-16

Exposure: R: 60 ms

G: 60 ms

B: 75 ms

ISO/Gain: 200

Acquisition method: SharpCap Pro

Stacking program: AutoStakkert 3.0.14

Processing program: RegiStax 6, PixInsight 1.8.8-6

I am so happy that I took the time to swap out the focal reducer for the Barlow.  Having the extra magnification is making this awesome!  

One of 79 known Jovian moons, Europa was discovered in 1610 by Galileo and is one of the four moons easily visible with binoculars and small telescopes. It's a little smaller than our own Moon, but it has a water ice crust and thin oxygen atmosphere. Due to its very smooth surface, it is thought that a water ocean exists beneath the surface, which could harbor life. Future NASA missions are planned to explore that possibility.

We also have a nice view of the Great Read Spot here. The GRS is a massive storm that has existed for at least the past 360 years, when it was first observed. Within the cyclone, windspeeds can reach 268 miles per hour -- much higher than Earth's hurricanes. The storm is 1.3 times the diameter of the Earth!

Saturn

Saturn has got to be my favorite to observe visually.  In my C8, it comes in sharp and clear, and it really looks like someone is holding a picture up instead!  I've only come close to imaging it as well as I can see it visually once or twice.

Unfortunately, I spent too long on Jupiter, and Saturn didn't stick around long enough for me to get all three color channels on it, unfortunately.  However, I originally set the scope up for planetary imaging on Friday night, although I only got Saturn before clouds rolled in.  So here's the one from Friday:

Date: 9 October 2020

UTC: 10 October 2020 03:51

Location: Easy Bay area backyard, CA

Object: Saturn

Attempt: 27

Camera: ZWO ASI1600MM Pro

Telescope: Celestron C8

Accessories: Baader Hyperion 2.25x Barlow, ZWO 2-inch 7-position EFW, Astronomik RGB Type 2c 2-inch filters

Mount: Paramount MyT

Frames: R: Best 20% of 2,002 frames

G: Best 20% of 2,002 frames

B: Best 20% of 1,848 frames

FPS: 13

Exposure: R: 75 ms

  G: 75 ms

  B: 120 ms

ISO/Gain: 300

Acquisition method: SharpCap Pro

Stacking program: AutoStakkert 3.0.14

Processing program: RegiStax 6, PixInsight 1.8.8-6

I'm always happy when I get the Cassini division and some detail in the cloud bands.  And I love being able to see the shadow cast by the planet on the rings.  

Neptune

While I was waiting for Mars to peek out from behind my neighbor's garage, I went and nabbed a more difficult target: Neptune.  I've only imaged it a few times in the past, but it's a lot easier to get into my camera's crosshairs on the Paramount MyT than on my Celestron NexStar SE.  However, I need to make a better pointing model for the MyT; its slews are off by a decent bit, and I wound up having to sync on a nearby star to get Neptune in the image, which required me to go outside and actually look through my red-dot finder because the field-of-view was so small with the Barlow attached (only 13x10 arcsec).  But I finally did get it in my sights.

Date: 11 October 2020

UTC: 12 October 2020 06:22

Location: Easy Bay area backyard, CA

Object: Neptune

Attempt: 4

Camera: ZWO ASI1600MM Pro

Telescope: Celestron C8

Accessories: Baader Hyperion 2.25x Barlow, ZWO 2-inch 7-position EFW, Astronomik RGB Type 2c 2-inch filters

Mount: Paramount MyT

Frames: R: Best 20% of 100 frames

G: Best 20% of 100 frames

B: Best 20% of 100 frames

FPS: 

Exposure: R: 3.5s

  G: 3.5s

  B: 3.5s

ISO/Gain: 300

Acquisition method: SharpCap Pro

Stacking program: AutoStakkert 3.0.14

Processing program: RegiStax 6, PixInsight 1.8.8-6

No gas cloud details for me -- it's just too small!  At only 2.3 arcsec across, that's only 13 pixels wide at my pixel scale.  But still, it's a bluish-green disk, woot!  (Actually the camera didn't capture the color that well for this one -- I think it was too small to do the color calibration correctly.  So I took a guess based on what I've seen in the eyepiece.  It's not really right at all).

Mighty Mars

Mars reaches opposition in October 13th, which is why it is so big and bright in the sky!  Now is the best time to image it.  Luckily for us this year, it's reaching opposition at a time of the year and time of the night when the ecliptic is also quite high in the sky -- it culminates at nearly 58 degrees high for me right now!  Higher altitude = better atmosphere, since you're looking through less of it.

I spent a good chunk of time on Mars, and waited around for times of better seeing.  Of the 5 datasets I collected, #3 came out the best for me.

Date: 11 October 2020

UTC: 12 October 2020 05:22

Location: East Bay area backyard, CA

Object: Mars

Attempt: 19

Camera: ZWO ASI1600MM Pro

Telescope: Celestron C8

Accessories: Baader Hyperion 2.25x Barlow, ZWO 2-inch 7-position EFW, Astronomik RGB Type 2c 2-inch filters

Mount: Paramount MyT

Frames: R: 50 ms

G: 50 ms

B: 80 ms

FPS: 20

Exposure: R: Best 20% of 2,004

  G: Best 20% of 2,001

  B: Best 20% of 2,001

ISO/Gain: 139

Acquisition method: SharpCap Pro

Stacking program: AutoStakkert 3.0.14

Processing program: RegiStax, PixInsight 1.8.8-6

The reddish hue of Mars' surface is a result of the iron oxide that resides in the dust on the surface. Mars has a thin atmosphere, which you can see at the edges of the planet as we look through it edge-wise. It is believed to have had a much more substantial atmosphere, but since the planet lost its protective magnetosphere 4 billion years ago, the solar wind has been stripping it away. The pressure on the surface is about the same as being at 22 miles above the Earth's surface, and it contains only traces of oxygen. 

Visible at the bottom of the planet is the southern polar ice cap, which is a combination of carbon dioxide ice and water ice. The darker areas have less of the red dust, which is why they appear darker.

I managed to get a fair amount of detail -- not the most I've seen from other imagers, but still cool!  I'll need to keep an eye on the seeing forecasts and give it another go here in the near future.

And finally, Uranus

Wrapping up our solar system tour for the evening (very late evening) is Uranus.  By the time I finished Mars, I figured I'd take one dataset on Uranus, and then finally get to bed.  I've also only imaged Uranus twice.

Date: 11 October 2020

UTC: 12 October 2020 06:53

Location: Easy Bay area backyard, CA

Object: Uranus

Attempt: 3

Camera: ZWO ASI1600MM Pro

Telescope: Celestron C8

Accessories: Baader Hyperion 2.25x Barlow, ZWO 2-inch 7-position EFW, Astronomik RGB Type 2c 2-inch filters

Mount: Paramount MyT

Frames: R: Best 20% of 100 frames

G: Best 20% of 100 frames

B: Best 20% of 100 frames

FPS: 

Exposure: R: 1s

  G: 1.5s

  B: 1.5s

ISO/Gain: R: 300

      G, B: 250

Acquisition method: SharpCap Pro

Stacking program: AutoStakkert 3.0.14

Processing program: RegiStax 6, PixInsight 1.8.8-6

Similar story here -- it came out quite gray, so I fuddled with the colors.  But with both Uranus and Neptune, they're definitely disks, not stars!  You can see this visually at the eyepiece really well, which is super cool :D

Processing

I need to update my planetary processing tutorial with my new methods, but until I finally have time to do that, here's the rundown.

• Open the video for each filter in AutoStakkert; auto-place appropriately-sized APs, and then stack the best 20% of frames.  (I have RGB Align ticked so that it aligns the next video to the last.)
• Open the stacked images in RegiStax and adjust the wavelets.  I prefer to do that in Linear mode -- I've gotten much better results with it.
• Bring the wavelet-deconvolved images into PixInsight, convert to grayscale (RegiStax likes to save TIFs in RGB), and apply LinearFit to bring each color channel to about the same level (picking one of the filters as the reference).
• Combine the three color channels using ChannelCombination
• Correct the color using ColorCalibration, with the whole image used as white reference and a preview box of the background as the background reference.  (I have found this works very well for Mars, Jupiter, and Saturn.)
• Tweak saturation and the brightness curve with CurveTransformation
• Use MultiscaleLinearTransform to do a little more shaprening
• Use MultiscaleLinearTransform again to blur the 1-pixel level, since some weird pixelated hatching tends to result from RegiStax's wavelet deconvolution that looks like debayering when it's not
• Bring finished image into Photoshop to resize (I shoot my videos cropped to a small window size, usually 640x480, to speed up acquisition & processing and reduce file size).  I usually change the DPI from 72 to 300, and then drop the auto-upscaled size from 450% to like 200-300%, and then do some denoising in Camera Raw Filter as needed.  (This is mainly so that my watermark doesn't look super pixlated when the image gets blown up online).

Planetary processing is much quicker than deep sky.  I can crank through a dataset in about 10 minutes, including the documentation.  There are probably some more techniques I need to learn to get the most out of the wavelet deconvolution, though.

Planets are a fun diversion from deep-sky imaging, and they provide some quick satisfaction!

Next post: #457 - Monday, December 21, 2020 - Conjunction Junction

Previous post: #379 & #380 - Saturday & Sunday, July 18-19, 2020 - Family camping, auto-guiding the Star Adventurer, and my new trailer!!

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#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.  

Setup

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 astrometry.net (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 astrometry.net 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.

Results

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.  

Details:

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

   2x120s

   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.

Conclusion

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!

Next post: #379 & #380 - Saturday & Sunday, July 18-19, 2020 - Family camping, auto-guiding the Star Adventurer, and my new trailer!!

Previous post: #346 - Monday, May 25, 2020 - For Science!!

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