M-42 Orion Nebula

First Light for the 0.7m!

First Light in astronomy is an old tradition filled with all sorts of interesting history. Some first light examples are not the best, while others are just tremendous. Ours was a little of both with the first exposure of the 0.7m telescope to the nighttime sky.  Don’t worry! It all turned out just fine!

The vert first exposure of starlight to the telescope was last week: Conditions were good with a nice clear sky and freezing temperatures. The wind was calm. The telescope had never been focused before and had yet to have a pointing solution…. so it really had no idea where it was looking.  We decided to aim it in the general direction of Orion and take the first images. Of course, they were blurry. The scope had never been focused before. At this point we got the CCD imager into automatic mode, making it take an image every second, non-stop so that we could run the focuser until we had the images nice and sharp…. out the focuser went, and the star images got smaller and smaller and smaller, then “kachunk!” The focuser had run out of travel, and the star images were not quite in focus yet!  The imager was perhaps a few millimeters away from achieving a perfect focus. The good news was that this was more than enough to engage in the time consuming process of collimating the primary mirror. A few hours later we had aligned optics, but we had to order a small spacer ring to push the CCD imagers little further out.

Betelgeuse just slightly out of focus

The bright star Betelgeuse just slightly out of focus. Note the doubled diffraction rings around Betelgeuse. Those should be single spikes. The focuser didn’t have enough travel to bring the camera to the needed distance away from the scope. Time to order a part!

The interesting thing about this telescope’s control software is the building of a pointing model. By taking a series of images all over the sky, the software does an astrometric reduction on each image and measures the slight variations in the telescope’s true pointing versus where it thinks it is pointing. This takes care of all sorts of interesting issues: flexure in the pier, telescope and mount, mirror sag or flop (none here!) and general pointing.  After some 20 images, we were able to point to any object in the sky and have it show in the images we took… just like that image of Betelgeuse above.

Once the spacer arrived this past Wednesday, we went out to install it and then wait for darkness to arrive. It was a nice clear and very cold night. The goal was to build a large pointing model and take some images of famous deep sky objects. I also wanted to test out a start-up and shut-down procedure that I had typed up earlier in the week.  That evening, we started everything up: the dome was homed and set to track the telescope. The CCD imager was on and cooled to -30ºC. The telescope was on, homed and tracking.  Would it reach focus! Absolutely! It was spot-on perfect. We then built a large pointing model with over 100 images. Now the telescope would find and center objects of our choosing, and it would track them for better than five minutes without needing any autoguider corrections. This is quite the telescope!

We chose some of the iconic late winter deep sky objects to share with you for official first light. These are all composites of four filters:

  • Luminance: a clear filter
  • J-C Rc: which was used as the red channel
  • J-C V: which was used as the green channel
  • J-C B: which was used as the blue channel.

The V, B, and Rc filters are Johnson-Cousins photometric filters used for photometry, the science of measuring brightnesses, which can lead to our understanding of an object’s surface temperature and size, among other things.

You might want to dim the room lights to see the details. Also, click on the images to see in a larger format. Enjoy!

M-42 Orion Nebula

The Orion Nebula, M-42, a star birth region about 1300 light-years away. This can be seen with binoculars and small telescopes easily. It was almost too bright for our CCD imager!

 

M-82 Galaxy

M-82, the Cigar Galaxy, a starburst galaxy about 12 million light-years distant.

 

M-81

M-81, Bode’s Galaxy, about 12 million light-years away. This resides very close to M-82.

 

M-1, the Crab Nebula

This is the Crab Nebula, M-1 in Taurus. This is a supernova remnant from a star that exploded back in 1054 A.D.

The next phase of this telescope’s use will be to collect scientific data. We have already taken images of U Gem and V Ori to calibrate our photometry and to see if we can produce good data for scientific publication. It has passed with flying colors thus far!

 

Happy people

Telescope Installation

With the building complete, the time had come to install the telescope. Arriving early on a Wednesday morning, whole crews of people came to be a part of the event: the crane operator, the contractor, architect, videographers, students and more!  It is not often that one gets to see such a large telescope lowered onto its pier using a crane. Below is a photo journal of that day’s events as well as the following day during which PlaneWave’s engineer, Matt Dieterich, and I spent the day wiring the systems and testing the electronics.

Initial pier inspection

Brian Carmody and Matt Dieterich begin the initial inspection of the dome and pier prior to getting the installation started.

The telescope arrives on a flatbed

The CDK700 telescope arrives on a flatbed from the storage facility. The crane and operator has already arrived, so things are about to get busy!

Uncrating

The various telescope components were then uncrated while on the truck.

Tethering the telescope's mount and primary mirror assembly to be hoisted.

Tethering the telescope’s mount and primary mirror assembly to be hoisted. It was at about this point that everyone’s heart rate went up a little!

The telescope is airborne

The telescope is now airborne, taking a short ride from the truck to the pier within the dome.

Enroute to the dome

With some serious expertise, the telescope was guided gently to the dome.

Slipping into the dome

The telescope being lowered through the dome’s shutter. While Matt (and everyone) looks on.

Sunrise with telescope into dome

The sunrise continues while the telescope is gently lowered to the three bolts that will hold it onto the pier.

Slowly, slowly, slowly. Using tag lines, the telescope is kept from swaying or rotating as it is lowered into the dome.

lowered within the dome

The telescope had to be lowered onto the three pier bolts. Tolerances were to the millimeter!

The telescope’s mount holes aligned perfectly with the pier bolts. Everyone breathed a sigh of relief at the exact moment when the scope landed onto the levelling bolts.

Secondary Mirror Assembly craned in

Now it was time to repeat this whole process with the secondary mirror cage and assembly.

Secondary arrives in place

The secondary mirror arrives in place and is bolted to the telescope.

The telescope's control system

Next to install was the telescope’s control system which feeds power, reads encoders and sends commands back and forth through a neat intranet system.

Components within

The many components within the control box.

Initial collimation

Using a laser mounted onto one of the two Nasmyth focal points, Matt begins initial collimation of the three mirrors. The corrected Dall-Kirkham optical design uses an elliptical primary, a spherical secondary and a flat tertiary mirror.

Many wires!

The many wires routed from the telescope’s interior, to the control box and to the control room computer.

Wires to be connected at the mount

Those same wires, this time a view from the base of the telescope mount. Within the mount are USB hubs, power supplies, and encoder systems. All must be wired correctly to allow proper control and to prevent twisting as the telescope moves in azimuth.

The pirmary CCD and filter wheel installed

The primary instrument will be an FLI CCD imager with a 10-place filter wheel, seen here at focal port #1 attached to the electronic focuser/de-rotator. All of these components are remotely controlled. 

Happy people

Brian, Matt and John: three happy and very tired telescope installers. The end of two days of work. Next steps? Clear skies to collimate and focus the telescope then build a pointing model.

 

Installation time

The 0.70m Imaging Train

The soon-to-be-installed 0.70m telescope will not have provision for eyepice viewing. Instead, telescopes of this size usually have an imaging system for collecting image data, among other instruments attached.  This telescope will have tow primary instruments attached at its two focal points: an imaging CCD and a fiver-fed spectrograph.

The imaging CCD will be a Finger Lakes Instruments (FLI) PL16803 4096×4096 9μm pixel array (16.8 megapixel array) with an attached 10-place filter wheel system.  The CCD is a non-antiblooming gate (NABG) system and is linear for most of its efficiency range. Below is a plot of its quantum efficiency. Given that it cooler can get 55ºC below ambient temperatures, we’ll be operating well below freezing every night, even in the summer. This means less thermal noise and clearer images with better data.

FLI CCD Imager

FLI CCD Imager right out of the box.

The filter wheel is a ten-place system, holding 10x50mm square filters for astronomical imaging. In this installation we’ll be using the system mostly for photometric and astrometric work, so the following filters have been installed:

  • Luminance: a clear filter.
  • Hα: Narrow band Hydrogen filter.
  • OIII: Oxygen narrow band filter.
  • SII: Sulfur narrowband filter.
  • g’2: The Sloan (SDSS) g photometric filter.
  • r’2: The Sloan r photometric filter.
  • B: Johnson/Cousins B photometric filter (Blue).
  • V: Johnson/Cousins V photometric filter (Green/Visual).
  • Rc: Johnson/Cousins Rc photometric filter (Red).
  • One empty filter position just in case 🙂
FLI CFW-3-10

The FLI CFW-3-10 filter wheel ready to accept filters and the CCD imager.

The CCD bolts right onto the filter wheel, then the whole assembly is attached to the focal plane of the telescope. All of this is controlled remotely using imaging software, in this case MaxIm DL and ASCOM.

Installing all this requires good lighting, a relatively dust free environment, small tools and some time.

Filters in their packaging

The color filters in their packaging, ready to be installed.

Installation time

Equipment at the ready: it’s time to install the filters.

With clean-room gloves on, each filter is removed from its packaging, then placed into the correct slot with the filter wheel. Two small plastic retainers are then screwed into place to hold the filter wheel in place. The lovely part of this system’s design is that the filters can be installed without removing the filter wheel’s cover. Many others on the market require complete disassembly – not fun.

Should you be interested, some external Links:

 

Exterior view with the lower shutter open and the dome rotated to point north.

The Dome Works!

Not a surprise at all, but we now have a rotating, opening and closing dome!  Next steps are to putty in the weather seal along edges, and it will be complete. The interior of the building is getting walls and paint soon. Lighting and network cabling come next followed by the installation of the telescope by end of January!  Stay tuned!

A wide angle look at the dome interior with the lower shutter open.

A wide angle look at the dome interior with the lower shutter open.

Exterior view with the lower shutter open and the dome rotated to point north.

Exterior view with the lower shutter open and the dome rotated to point north.

All three of the observatory's domes visible for comparison.

All three of the observatory’s domes visible for comparison.

Below: Two short movies of the dome shutter being opened. This is a two-part process with the top shutter opened first followed by the lower shutter which tilts out. The top shutter’s lower edge overlaps the bottom shutter thus preventing weather from getting inside.

 

There is a Roof and a Dome

Progress has been swift on the construction of the new building.  Roofers have installed the waterproof roof layer and sealed around the dome’s base structure (framing). The dome has been built in place, and the shutter also installed.  Interior work now progresses with the installation of the walls, trim, lights and such. Remember that for any of the images below, just click on them for a larger view.

Prior to pouring the concrete walkway we were expecting both rain then snow and freezing temperatures. Heating pads were placed to prevent frost on the ground before pouring the cement.

Prior to pouring the concrete walkway we were expecting both rain then snow and freezing temperatures. Heating pads were placed to prevent frost on the ground before pouring the cement.

One wall has siding in this image, and the dome opening has been covered to protect the interior from rainfall.

One wall has siding in this image, and the dome opening has been covered to protect the interior from rainfall.

All four exterior walls now have been sided, ventilation louvers have been installed, and the roofers are working on the rubberized layer on top the structure and around the dome, base frame.

All four exterior walls now have been sided, ventilation louvers have been installed, and the roofers are working on the rubberized layer on top the structure and around the dome, base frame.

Inside the control room, the base bearings of the dome have been unpacked for inspection and comprehension! So many parts are in this package, that it is a little mystifying.

Inside the control room, the base bearings of the dome have been unpacked for inspection and comprehension! So many parts are in this package, that it is a little mystifying.

The view of the telescope room through the framed wall of the control room. The window casement has been installed along with initial conduit for electrical. network and telescope control lines.

The view of the telescope room through the framed wall of the control room. The window casement has been installed along with initial conduit for electrical. network and telescope control lines.

The dome is almost complete in this image taken at 6:30am with the sun rising. The dome's motion is smooth and has that familiar rumble to it as it rotates in azimuth on its well-aligned and level bearings.

The dome is almost complete in this image taken at 6:30am with the sun rising. The dome’s motion is smooth and has that familiar rumble to it as it rotates in azimuth on its well-aligned and level bearings.

A wide-field image of the dome interior. Note that edges are a little warped in this image due to the camera's odd stitching of the frames. You can see the top of the pier and the orange power line system for dome operations which make the system effectively wireless. No wires will be dangling down from above to control the dome's motion.

A wide-field image of the dome interior. Note that edges are a little warped in this image due to the camera’s odd stitching of the frames. You can see the top of the pier and the orange power line system for dome operations which make the system effectively wireless. No wires will be dangling down from above to control the dome’s motion.

Roof is complete. Dome is complete. Door has been installed.

Roof is complete. Dome is complete. Door has been installed.

The Structure Takes Shape

This has been an exciting couple of weeks. As we have seen our first frost of the season (no snow just yet!), we have been putting up the frame and the structure of the building.  Click on images for full size.

The first wall goes up

The corners of the building have been placed and the first wall frame goes up.

Work on the wall frame continues

Work on the wall frames continues. Soon after this they will be sheathed with plywood.

The structure takes shape.

The four walls are up, and the roof’s lower layers have been installed. There is also a ring for the dome.

The entrance to the structure.

The entrance to the observatory. Note the walls inside have yet to receive their plywood, and the floor needs to have concrete poured.

Frame viewed from the rooftop

A view of the dome base framework from the rooftop. Imagine a large telescope on the pier with a 16′ dome surrounding it. The roof has a slight pitch to allow water and snow to run off to the north. 

Where's the dome? Here!

Another view from the roof. Where is that dome? Here it is! It’s the bundle of materials on the pallet. Some assembly is required. The black mats are covering what will be the walkway to the building.

The Pier is Poured

Yesterday the concrete for the telescope’s pier was poured. What an exciting moment in this telescope’s history. The contractors used a very large Sonotube held rigidly in place with a temporary framework of wood and cables. Internally there is quite the framework of rebar to help reinforce the pier’s strength. A few conduits were also placed inside for electrical and data lines which will drive the telescope. Images (click on them to enlarge):

pier

A view of the building’s site with the framework around the Sonotube for the pier.

pier

A closeup of the pier near the completion of the pour.

Pier

A wide field view of the site.

0.7m Telescope Observatory Construction Begins

This will likely be a series of posts involving some very exciting news here at the observatory: We are adding a new observatory building complete with dome and telescope! Very much exciting times! The new structure will be 16’25’ in dimension with a 16′ diameter dome on the south side. The interior will be divided into two sections: the telescope/equipment room and the control room. A wall with large glass window will separate the two so that people can work with low-level red lighting while keeping the telescope and its sensitive instrumentation in the dark and away from the heat of humans which can cause disturbing air currents.

Artists Impression of the 0.7m Dome

Artists Impression of the 0.7m Telescope Dome.

The telescope is a PlaneWave 0.70m diameter modified Dall-Kirkham optical system with two ports. One port will hold a CCD imager with filter wheel. The other will attach to a fiber-fed echelle spectrograph.  It is difficult to imagine the scale of such an instrument. The telescope alone weighs over 1500 pounds! For a comparison here I am standing besides the same model of instrument at a recent American Astronomical Society meeting.

PlaneWave 0.7m telescope with the author

Ground breaking started a couple of weeks ago. Concrete pouring started today for the pier footing and the footing for the building’s foundation. This will help give a sense of scale the final structure.

The Initial Dig

The boundaries of the structure have been posted here with wooden stakes. The ground is being prepped to dig for the base level foundation.

Gravel base

The gravel base for the concrete has been laid here. Looking closely you can see the inset region in the gravel where the pier for the telescope will rest.

Initial Concrete Pour

The initial concrete pour which took place today. The central region is the base for the telescope pier. The surrounding is the base for the building’s foundation.

 

 

Eclipse Photography – Some Notes for the August Event!

Eclipses are exciting whether they be partial, total or annular. On August 21st of this year, the USA will have an awesome opportunity to see a total solar eclipse pass right across the entire country from Oregon to South Carolina.  People have already got their hotel rooms reserved, rental cars spoken for, and plane tickets purchased. Wherever you choose to go, you are likely to wonder about capturing this event by camera. Here are some thoughts, in no particular order (but I will try to keep it logical).

Never seen an eclipse before?  You might want to consider NOT trying to photograph the eclipse at all!  Sit back and enjoy the event. Total solar eclipses are short in duration, totality, that is. At the location of greatest totality duration (Southeast of St. Louis, MO), the totality lasts only 2m 40.2s… that is just almost about 3 minutes in length. You really want to be looking up at the corona at that point and making all sorts of exclamations!

Determined? You really want to capture this with a camera? Ok! Read on!

Initial Words of Wisdom:

Start planning NOW. Obtain your gear as soon as possible. This accomplishes two things: You will have the better choice of gear with sufficient lead time. Closer to the event, gear will be more difficult to buy. Also, you will have time to do this next important thing: Practice with your gear now!  Learn your camera, inside and out. You want to know ALL there is to know about the equipment you plan to use. Be able to use it without manuals! You WILL NOT have time during totality to learn new things about your gear. Play. Try solar photography on every clear day. Learn what works for you and your equipment now.

Wide Field Photography:

Some of the coolest looking eclipse shots are wide field images taken with fisheye lenses or wide field lenses to capture scenery and the eclipse at the same time. You can even set it up to take images every couple of minutes throughout the whole event and get a lovely series.

A video camera set to wide-field and left attached to a tripod will capture the whole event automatically, and will include sounds of the celebrations around you. Aim, turn on, record. Done. A steady tripod is handy. You might also tape a sign onto the tripod stating “do not disturb”. Check out this video from observers in Queensland for their last total solar eclipse.

Total Solar Eclipse from Queensland Australia

Individual shots: a DSLR or point and shoot camera should be on a tripod. You can take images at short exposure lengths 1/500s or faster depending on your ISO. This will capture the day-lit scenery and the sun. If the camera is well mounted, be sure to aim the middle of your eclipse series towards the center of the frame. Below is a typical wide field setup: a DSLR with 16mm fisheye on a stable tripod. Note that many new DSLRs also have the capability to shoot video <hint hint>.

Wide field imaging setup.

A Nikon D7000 with 16mm fisheye lens for wide field photography. This will capture good images of the surrounding scenery and the eclipse at the same time. No need for a solar filter here. The tripod keeps it all stable.

Below is an image taken with a Nikon D810 at 100 ISO f/8 for 1/640 second exposure. It was resting on a tripod and released manually (i.e. finger on the shutter release button). Shorter exposure times will show less of the scenery, but might show the sun and the corona a little more clearly.

Fisheye image of sun at noon.

This image taken with the setup seen in the photo above, a D7000 ISO100 1/640s f/8 on tripod with 16mm fisheye.

If you have manual focus: set it to manual and focus it onto a distant object and then leave it there. Also, set the ISO, shutter speed and f-stops (aperture) and leave it on manual mode. You will then see the surroundings get darker at totality instead of having the camera keep trying to take properly exposed shots in the darkness of totality.

Many cameras have built in interval timers. Set it up, start the sequence and go enjoy looking at the eclipse!

Telephoto/Telescope:

This gets a little trickier. First and foremost a WARNING: YOU NEED A SOLAR FILTER for your camera and your eyes! DO NOT MESS AROUND HERE. The sun will cause irreversible harm to your eyes if you look at it. It will do more harm more rapidly if you use a telephoto lens without proper filtration!  Got it?!  Good!  This is really important!!!  

Appropriate filters are those made for solar observing and DO NOT include welder’s glass, exposed film negatives, sunglasses, and similar. Good filter material:  Baader Solar Film. You can buy a lot and make a ton of filters for your cameras and friends’ as well.  Buy it NOW or you will find it much more difficult to get closer to eclipse date.

You can buy Baader Solar Film on Amazon.com.

A filter should be placed in front of your lens until just the second before totality. This protects you and the camera and the lens. You can then watch the eclipse as it progresses. I recommend taping the filter onto the lens hood to protect it from being blown off by wind and to prevent interested people from trying to remove it. That is a no no.  Throughout totality and into the moment when Bailey’s Beads are visible, you can take the filter off and shoot without it.

Experiment with your setup and filters well in advance of the eclipse date. Practice using your camera to take solar images. Do this often. Get to know your camera inside and out. Be able to operate it manually without any guide book.

Eclipse imaging setup.

The telephoto setup: a D200 with 300mm telephoto. There is a Baader solar film filter on the front. A right angle viewfinder is attached. This was a windy day! The sturdy tripod helped a lot.

Tripod: You need one with telephoto lenses.  You need a sturdy one.  The sturdier, the better. For a 300mm lens on a full frame (FX) camera, I use a Manfrotto MT055XPRO3 055 Aluminium 3-Section Tripod with Horizontal Column.  There is also the issue of the tripod head. I use one with slow motion controls, also a Manfrotto item: Manfrotto 405 Pro Digital Geared Head. These are not inexpensive items! Whatever you use, the ability to slowly move the pointing as the earth rotates is very helpful. It just has to be stable as a rock.

A word about tracking: Some of you will be tempted to go find an astronomical tracking mount for this event… thinking that you can mount the camera onto the mount and just let the thing track through the event automatically. If you have not done this before, avoid the temptation. A good tracking mount is much more expensive, as it has to be massive to hold your lens and camera combination. Alignment with the earth’s rotational north pole is not easy in daytime. You will need batteries or another power source to drive it. Just no. It is EASY to manually track the sun in a camera’s viewfinder. Keep it simple. Travel lighter. Save money. If you’re a pro and plan on doing this, then you already know what you are up against. No need to discuss this any more.

Lens:  A DSLR and a telephoto from 300mm up will be great. 300-400mm lenses are more than adequate for some excellent photography…. There is no need for a massive telescope with 8” open aperture and 1200mm of focal length. The sun is bright. The sun is also large at some 0.5 angular degree in diameter. If you use a zoom lens, be sure that you can lock the zoom feature. Use duct tape if it does not have a locking feature. Some of them will zoom in or out on their own due to gravity! Not fun if you are trying to keep things equal throughout the event.

Here is an image taken through a 300mm telephoto using a Baader solar film filter. It has been cropped but kept at 100% scale from the camera:

Partial eclipse image

Partial phase of the 1 August 2008 eclipse seen from Novosibirsk, Russian Federation. Nikon D200 and 300mm telephoto, iso1000 1/5000s f/7.1

Camera: The camera will be better if it has manual controls and manual focus. Having a remote shutter release is good in that it will reduce vibrations. Setting focus: With the solar filter on, focus on the edge (limb) of the sun until it is crystal/razor sharp. You might even have a couple sunspots to focus on. Most camera’s autofocus systems will do this nicely. Once focused, switch the camera and lens to manual focus and DO NOT touch it throughout the event. If your camera has mirror lockup mode, you can use that if you wish to reduce more vibration, but you will have to look through the viewfinder occasionally to center the sun, and that requires a mirror.  I never bothered with the mirror lockup feature for eclipses, and my images were fine.  Why setting to manual? You should expect to change the shutter speed and maybe even the aperture throughout the eclipse in order to get best exposures. The moon covering the sun will dim the event, little by little. As totality is reached, you will want to try to capture the inner corona and flares/prominences with short exposures… and then use longer exposures to capture the outer corona, requiring longer exposures. You will be VERY busy at totality.

Large zoom lens setup.

A Nikon D810a with 200-500mm zoom, right angle finder and home made Baader film solar filter. This is the limit for the tripod before things get too shaky. Add a GPS receiver and remote shutter control, and this is a perfect setup.

Working end of D810a and zoom.

The working end of the D810a and massive zoom lens. The right angle finder allows one to be looking away from the sun while taking photos. Add the shade of a rimmed hat and the extended cardboard from the filter assembly, and taking solar photos is a snap!

File Types: Most modern DSLRs, and digital cameras in general, allow one to select various modes of shooting: High, Medium, Low resolution, Raw, NEF, etc. My recommendation is to have your camera shoot both high resolution Raw images and JPGs as well.  Depending on your camera make/model, this will result in raw images of type NEF, RAW, or CRW and also store JPGs. These raw images can be edited much more cleanly than JPGs. Images will be large! Have memory to handle this. My last eclipse trip saw 350 images in all from eclipse start to finish. Also turn off any compression modes and image processing (sharpening, etc) that cameras are likely to do. Set your camera’s time and date as accurately as you can using Universal Time. If you have a GPS attached, then this will be taken care of for you.

Totality: Much has already been written about what you can expect to see during totality. You have to decide what you are going to do, and in what priority. Some will want to just look up and enjoy. Others will want to take as many photos as possible. Assuming you are going to take as many photos as possible, read on.

  • Right before totality, you have the option to remove the filter and try to capture Bailey’s Beads. With the camera on high-speed multiple exposures, take as many images as you can, as fast as you can. You can also get the Diamond Ring Effect if your timing is good. Another option here: try to get both the beads and the ring effect at the END of totality. It happens on both sides!
  • Remove the filter!
  • Take many photos at many different exposure times. Long exposures will show the outer and fainter corona. Shorter exposures will show the brighter inner corona and prominences. If you take a series of images with a wide range of exposure values, then you can combine them using high dynamic range software to get some amazing imagery.
Inner corona image

A short exposure of the 1-Aug-2008 eclipse. Note the small red prominences and just a hint of the corona. The human eye will see more corona than this photo shows. Nikon D200 300mm iso1000 1/6400s f/7.1

Outer corona image.

Long exposure photo of the same eclipse showing the fainter outer corona. Nikon D200 300mm iso1000 1/160s f/7.1

Gadgets: Below listed are some helpful things to have around. Not all are necessary. Take what you think would be helpful.

  • A good watch.
  • GPS receiver/geotagger attached to the camera: these can log your position and the time onto each image you take. Great if you are doing science or working with the Mega-Movie-Photo-Team.
  • A right angle viewfinder for the camera: this is really helpful, as it allows to look down into the camera viewfinder instead of at the same line as the sun. Combined with a brimmed hat, this is a really nice gadget to have. Some also have 2x magnifiers which help with focusing.
  • Batteries: for all your goodies like the camera, GPS, cell phone, etc. A Charger is also handy. You are not too likely to need to change freshly charged batteries in the middle of the eclipse unless your camera loves to eat them up :-/
  • Extra Memory Cards for the camera.
  • Compass: not all that helpful, but just in case you need to find south…
  • Pencils and pens and notebook.
  • Maps: in case you need to avoid weather, having a paper map of the area is helpful.
  • Bug spray: sometimes bugs can really bug you!  Mosquitoes will come out in at totality.
  • Sunscreen: yep – sun burns are no fun.
  • A brimmed hat: this helps to block sun from your seeing the camera’s field of view properly.
  • A vest with a ton of pockets: to hold tools, parts, lenses.
  • A pocket knife (Swiss Army style with tools): handy to attach tripod screws to camera and many other things.
  • Duct tape: there is always a need for duct tape.
  • Plastic bags: to cover camera and gear against rain and dust.
  • Water and food: keep yourself energized and hydrated.
  • Microfiber cloth and lens dust-off-bulb: helps to clean the optics and the viewfinder window.
  • Your glasses and or contact lenses. Have an extra set.
  • Solar eclipse glasses. These are fun and allow you to see the eclipse with the unaided eye while it is in the partial phase.
  • An odd one: Permission to be where you are located!  Be mindful that it will be easy for you to be tempted to trespass onto lands for which you do not have permission! In case you do venture onto unknown property, bring photo ID with you.

Links to other helpful sites:

Focuser Assembly

Summertime: Time for Repairs and Maintenance

What goes into the repair of a telescope? A lot of time and technical operations.

Our robotic observatory has a 10″ Ritchey–Chrétien optical system. The system focuses by moving the secondary mirror in and out using a very finely controlled motor assembly. After years of hard work, this little assembly got jammed up solidly. The company that made the telescope has moved onto bigger and better things, namely producing to-order optics. Contacting them resulted in contacting an original engineer (James Olson… yes…) who was willing and able to do repairs on the focuser.

The focuser was removed: an intricate couple of hours removing the secondary mirror, detaching all the electronics for the dew heater and focus motor, and then balancing the telescope, since it had lost a lot of mass from its front end. The focuser assembly was then shipped to James in Arizona.

The focuser was taken apart by James, polished, lubricated, re-assembled, and tested for days before he shipped it back to PEA. Once back at its home, the focuser had to be installed back into the spider (24 bolts), the secondary mirror installed onto the end of the focus assembly (three push bolts and three pull bolts), then the whole thing tested for proper movement. A dozen runs of the focuser later, the electronics and mechanics of the system were AOK and ready for the next phase. The next phase?

Collimation! Having removed everything out on the secondary mirror region, everything was out of alignment. All the optics have to be centered on the optical axis, and aligned perfectly both perpendicularly to the optical axis, and rotationally, as these are a matched pair of mirrors… Sigh. That was a time consuming but worthwhile task. Last night the system was star tested. Success! An image of Altair was used for final touches on collimation, and an image of SS Cygni was used to test scientific data usefulness. SS CYG is now in outburst (huzzah!) and the data are perfect! We have V magnitudes to +/- 0.004. We are back in action!#astronomy #photometry #repairs #observatory #robots#PhillipsExeterAcademy

Focuser Assembly

Focuser Assembly: The secondary mirror is in the black housing inside the telescopes truss tubing.

Focuser Assembly

Focuser Assembly

Focuser Assembly

Focuser Assembly

Electronic Controller for Focuser Assembly

Electronic Controller for Focuser Assembly. This unit controls heaters, fans, focus position and more.

Altair being imaged at perfect focus

Altair being imaged at perfect focus. Success!