Orion Ranch Observatory Blog

My initial setup had too much back focus from the focal reducer, resulting in distorted stars around the edge of the field of view.  The off-axis guider pick-off mirror was also shadowing the image, resulting in unusable images.  

My initial attempt was to mount the OAG directly to the camera, removing about 24 mm of back focus.

Unfortunately, even after removing the spacers on the guide camera and spacing the pick-off prism out from the center, I still couldn’t get the guider back focus short enough to match the imaging camera.

I finally had to add the camera rotation adapter which adds about 6 mm back to the camera path.  Removing the protective window off the guide camera let me get it close enough to get both cameras in focus at the same time.  I’m not thrilled about that, and don’t know how much moisture and dust may eventually infiltrate the guide camera, but that was the only way to get things to work.  However, things worked out well and with the altered orientation, the pick-off prism no longer blocks the imaging sensor.  

After adjusting the primary focus mirror and setting the Crayford about as short as possible while maintaining a few mm of adjustment, I get nice round stars to the edge of the field of view and tiny pinpoint stars on the guide camera.  Guiding is actually so good that I’ll probably have to start dithering the images to average out the few hot and dead pixels I have on the camera.  I probably need to create a new dark library to minimize those, but the results turned out pretty well.  There’s still more vignetting around the widest edges of the images, probably due to narrow throat of the SCT adapter.  I still want to find a 3.3″ adapter for the focuser, but I’m reluctant to invest in a much more expensive focuser to get the wider opening.  Below is my finished process of NGC 891.  Turned out pretty good, if I do say so myself. 

After the solar eclipse in April, it took me quite a while to get around to putting the observatory back to it’s normal nighttime viewing state.  Unfortunately, then something went wrong with the serial interface between my controlling computer and the motor drive system that moves the roof, so I haven’t been able to open it for some time.  

To top it off, the custom infrared remote control that would allow me to manually open the roof had it’s batteries leak and completely ruin the circuitry.

In order to get to the motor drive without crawling completely up into the roof framework, I needed to get that working again, so I eventually wrote some code on an Arduino Nano and replicated my command set to allow me to open and close the roof using the Arduino connected to a laptop. 

I had to hotwire the old remote to let me generate a few codes just so I could confirm the timing and format, since it has been twenty years since I developed the original protocol!

Once I had that working, I decided it was finally time to do something I’d planned to do for a long time, and developed a web based interface on an ESP32-S3 embedded microcontroller with Wi-Fi.  Now I can open the roof from any web browser on my network rather than having to remote into the one PC that was interfaced to the drive.  Now I just need to write an ASCOM driver so that Sequence Generator Pro can control it directly.  

Once I got the roll-off roof working again, I had to put my astrophotography rig back together.  For the eclipse, I remembered that I had the 0.7x focal reducer for my C11, which worked great during the eclipse, so I want to try doing some imaging through that.  About this time last year, I had developed a focus motor drive for my old Zhumell Crayford SCT focuser, but never really got the chance to test it properly.  

I still have to use the SCT thread adapter to mount that focuser as opposed to the larger 3.3″ opening on the C11, but the focus motor works quite well, letting me lock down the mirror and eliminate mirror flop.  I’d also bought a new small Askar off-axis guider to replace my old huge Taurus Tracker OAG.  By the time I got the entire optical chain set up with the heavy focal reducer, focuser, and QHY-247C camera, things were WAY off balance.  I had to add the final counterweight on the CGE Pro and shift the OTA way forward in the mount.  Balance is great now though!   

First light with the new setup (a month after the clouds rolled in the instant I got everything working and then ran through a full moon cycle), guiding is great, but the back focus is several centimeters too long and thus there’s quite a bit of field curvature around the edges of the field.  The pick-off mirror of the OAG is also causing major vignetting in the side of the image.  It needs to be rotated 90 degrees and shifted out as far as possible.  I THINK I may be able to shorten the length enough to reach the 146 mm recommended by Celestron, but that remains to be seen. 

This is a simple stretch of this first stack.  I doubt I’ll finish processing this vs. trying to improve the setup and redoing it.

I’ve managed to generate new darks and debayer all of the frames from my QHY-247C on my AT-80LE.  I’m post processing these in Photoshop and have processed the six 6-millisecond frames from totality.  I have six times that with exposures from 1-6 ms, so hopefully I can process all of those to similar levels and make a finer resolution animation.  Here it is in GIF format.  I may do a video version as well to see if it looks any better.  You can visit the gallery here.

Unprocessed and not deBayered, but here was totality!  Watch for updates in the coming week or two!

It’s still not looking great for Monday, but we’re so borderline it’s painful.  The Clear Sky Chart is showing a tiny gap right around the start of the eclipse and clouding back up after totality.  However, this morning vs. last night is showing less morning cloud and a bit wider slot overall.

Looking at the map, it’s apparent that up through Arkansas will potentially be the best viewing, but I don’t think we want to try a last minute trip.  We’re so close the back edge of this front that just a bit of shift will greatly change what happens here.  That tail edge just needs to shift a bit further south and it will miss us completely.  We’re going to keep praying for a bit more of a break in the clouds!  

After weeks of prep and quite a few days/evenings of cleaning, the observatory is cleaner than it’s been in years and I have both piers set up for solar observing and photography.  Test runs of photos with my QHY247C on my AT80LE look great, and all is ready to go if the weather will cooperate!

The framing isn’t perfect on the piggyback, but as long as I move it just before totality, it should be perfect for the corona shots too!

I’m not normally outspoken about my faith, especially online, but when people ask, I’ll tell them that I can’t look at the wonders and majesty of this universe and the elegance of the physics that we’ve discovered and believe that it all occurred by random chance.  I also firmly believe in the power of prayer and that God will answer the prayers of the faithful.  It may not always be the answer we want, but what could be a more amazing example of His glory than this eclipse!  So please join me in praying for good weather and safe travel and observing for all of those wishing to see this eclipse!

Well, over the weekend, weather.com started showing the long term forecast for April 8th, and unfortunately it’s not looking good.  That said, given that they haven’t been able to accurately predict our weather here eight hours ahead of time, I’m hopeful that they’re way off here.  The forecast has been changing significantly every time we look at it, varying from partly cloudy with a 25% chance of rain to up over 50% then back down to 25% and now at 32% chance of morning showers.  We’ll keep praying that will change significantly, but right now it is likely to be a disappointing event here in Central Texas.  Things aren’t looking much better, anywhere along the line in Texas, although down at Uvalde they’re saying partly cloudy.  We’ll keep praying for better weather and keep preparing for the day.  If everyone can join in this Easter weekend, I’m sure we can have a miracle!  

Historic predictions from the National Weather Service, as well as my own recollection and records of April weather give us a 50/50 chance of having clear skies here in Central Texas and the rest of the state.  As we’re sitting here today under a band of cloud cover that spans the entire eclipse path with the possible exception of upstate New York and Maine, I’m not overly optimistic about the chances of being able to drive a few hours to get out from under any clouds we may have here, but you never know.  

We’re still planning to host an event here for friends and family, and we’re open to others who may wish to come enjoy the eclipse with us.  We’re still getting settled in our new house, so some of the other things I had hoped to have done by eclipse time aren’t going to happen, but there’s still room for day guests for the event.  That said, I’m also prepared to load up the truck and drive to Dallas or Fredericksburg if the weather doesn’t cooperate!  

Never look at the sun without eye protection!

The next great total solar eclipse is now less than a year away, with a path from Mexico, up through Texas and much of the Eastern United States, leaving through northern New York and Maine. Given the rarity of such an event many people will be planning to make the trip to see the eclipse somewhere along the path. While the rest of the country will see a partial (penumbral) eclipse, only those along the marked path will see the Sun totally blocked by our Moon. Having had the opportunity to see the 2017 Total Solar Eclipse from Ravenna Nebraska, I have to say that it is an indescribable experience that you have to see for yourself!

Path of the 2024 solar eclipse, courtesy of Xavier Jubier’s interactive Google Map.

Here in Central Texas, we will get a beautiful view of a total solar eclipse across most of the Hill Country, with the centerline crossing through (or very near) Kerrville, Fredericksburg, Enchanted Rock State Park, Lake Buchanan, and Lampasas, continuing on through Gatesville, Hillsboro, Ennis, Sulphur Springs, and Clarksville. Most of Austin , Dallas/Fort Worth, Waco, and about half of San Antonio will also experience at least a short period of totality.

Path of 2024 solar eclipse through Texas.

Orion Ranch Observatory is situated about 19.5 miles off the centerline, so we’ll have almost four minutes and eleven seconds of totality compared to the 4:24.7 on the centerline.  For the extra 14 seconds of totality, it’s really not worth fighting with moving all my equipment to the centerline, assuming the weather holds.  Based on our weather this year, I’d say we’re about a 50:50 chance of being clear vs. cloudy, which matches the predictions for the area based on twenty years of data (see below).  Still, Texas is the best chance in the country and only western Mexico would be better.  We’re hoping to have a big event here (fill out the contact form if you’re interested in joining us), but I plan to look for options within driving distance, just in case.  My uncle’s farm is down by Fredericksburg, so I’m somewhat covered to the south, and Hillsboro would be easy to get to going north.  Even further gets us near Paris, TX, where my wife grew up!

Orion Ranch Observatory Totality

There are plenty of other excellent opportunities for visitors to the hill country.  The Eagle Eye Observatory (formerly the Austin Astronomical Society’s dark sky site) at Canyon of the Eagles on the north side of Lake Buchanan is just past the centerline, which passes right through the Burnet County Park on the north side of the lake.  There’s another park on the south side which is also on centerline.

Lake Buchanan and Surrounding Area including Oatmeal, (home of Orion Ranch) 

About half way between Burnet and Fredericksburg is Enchanted Rock State Park.  I doubt they’d let anyone set up a telescope on the rock, but imagine the view from up there and watching the oncoming shadow!  There appear to be some neat places to stay around the area as well.  

Enchanted Rock State Park and area.

Enchanted Rock

Now, as to weather, Jay Anderson has an excellent website that covers the weather forecast for the entire path of the eclipse.  Below are a couple of his images showing what we can expect.  As my own experience predicted, we’re at the 50% chance mark through most of Texas for that time of year, but that’s better than the rest of the country!

Cloud Fraction Map for April

Cloud Fraction Chart for April

It’s easy to find information on the eclipse with a simple web search, but eclipse2024.org has put together a very good set of resources and links, including viewing locations and an article on why you must see the total eclipse and not just a partial eclipse.  There’s also plenty of good information on viewing and safety, as well as links to buy viewing glasses.  There’s also information there on this year’s annular eclipse in October.  It will be passing just south of Fredericksburg on a Saturday, so I’ll probably try getting down there if I can!  

So happy observing!  I hope you get a chance to see something like this as it’s something you’ll never forget.  Feel free to contact us if you’re interested in attending our event at Orion Ranch Observatory.  And always remember:

Never look at the sun without eye protection!