Blog – Page 13 – IMT3b Observatory

IMT3 Build Update – Part I

Ok so it’s been a while, well more than a while, as Douglas Adams once said, ‘you thought it was a long way down the road to the chemist’ well I can tell you it’s a long road to building a commissioning an off the shelf observatory too! So even though the observatory is nearly complete I though I would share the build experience here on this very blog.

So it’s not been helped by the weather, it’s not been helped by the other building work on the house and it’s definitely not been helped by working so much either. The Ripton Windows team, incidently who are building a lovely Orangery for me as well as some other works, were also good enough to take on building the base and laying the electrics and network access.

The base for the pier was a single discrete 1m cube of concrete and surrounding that a slab of concrete of 3m square and 150mm deep. This was so the pier is isolated from any vibrations from the dome rotating or people walking about inside the dome.

The team from Ripton took a few days to dig the hole, pour the concrete in a couple of stages and then we had many weeks for it to set due to a delay in the Pulsar 2.7m dome arriving for install. I also laid a shingle surround to act as a french drain and included a homemade soaraway, more pictures later.

Work started with digging out from the outside in using a JCB, the team did a quick and good job, considering all the clay.

After some rain holding off the final dig, the team managed to dig out the rest of the base including the much deeper but separate 1m cube.

Scalpings were then laid and shuttering to act as a former for the central cube was fitted, this included DPC to help keep the cube from being effected by the surrounding area. PVC piping was also added before the mix was poured for the data and electric cable runs.

Before long the concrete was poured for both the inner and outer segments, now you can see the level below ground to which we dug to make sure we were inside the planning rules for the area.

Creating my very own stone henge, allowed me to see where the dome would finally come to.

I then went one stage further and placed a plastic pipe vertically to see the height of the final dome once fitted.

Finally my favourite electrician Steve fitted the main power to the outside and included CAT6 cable back to the main fibre hub for me.

This was run under the ground through plastic pipe, even though the cable was armoured, in case we wanted to run additional cables later.

Viewing Report 29th/30th June 2019 – IMT3 Observatory & Travel Scope

Viewing time period – 22:01 – 03:18

Tonight Bob will be learning how to control the observatory and using the Tak FS102 to trying imaging. Meanwhile I will be setting up my new Paramount MyT on its Berlebach tripod and with a new Sky-Watcher Esprit 120 mounted on top. The business end has my new QHY168C, yes I purchased a 2nd one, they are that good.

Whilst Bob played, I setup the travel kit on the new patio. I realised I could connect the camera through the USB on the MyT to one cable that won’t get snagged. I will however need to connect a power for the camera as that is currently trailing. There is a power connector on the back of the mount but I believe it is only rated to 1amp. There is however another power out which is rated at 7.5 amps so I will buy a Tycoon KPPX-4P 4 pin couple of connectors and makeup a cable so I can plug into that directly.

So I connected to TheSkyX with the mount and slewed to Arcturus. I could not connect the QHY camera to TheSkyX as I seem to be missing a driver. I will take a further look tomorrow to see if there is one. Instead I used the EzCap software they provide and connected the camera to that.

I focused manually as I have not motor focus to keep things simple, and soon had stars in view. I then did a manual spiral search until I found Arcturus and then synced on it. I could then slew around the sky with ease.

For polar alignment I have ordered (my friend GingerGeek has ordered) a PoleMaster mounting plate that I can use, this will make it easy to align. Tonight I just plonked the mount down without any polar alignment, thus anything more than 10 seconds produced trailing.

I tested cooling the camera, slewing and parking, although I need to see the park position 180 degrees from the current position to allow the scope rings to be in the right place for removing the OTA.

The scope and the mount and the camera make a great travel setup, each component is not too heavy to move by itself, the connection and setup is fairly straightforwards and I really do look forward to testing this out in October in Tenerife. I do need to test running from a car battery to see how long things last. I have my car battery I use for astronomy on charge and will test next time.

The connection of the camera to the flattener is a push fit and is missing the luminance filter. I will order the right adapters from Modern Astronomy so that I can fit later.

So I still have a few things to make, buy, test and do before October but good progress tonight on the travel setup front.

Meanwhile Bob has been making good progress with the Tak FS 102 in the IMT3. Imaging Arcturus and testing lengths of exposure on different objects such as M13. Some pieces of the sky Bob was imaging at 5 minutes unguided and others such as M13 only 3 minutes. I need to look at why this is given I now think the polar alignment from last night is excellent.

I reset the FoV indicator for the Tak FS102 in relation to the main 12″ scope. I need to find a way of slewing to given object for the offset scopes. I also need to be shown how you use SGPro to slew too, rather than using TheSkyX, so a slew, plate solve and then final adjustment.

Viewing Report 28th/29th June 2019 – IMT3 Observatory

Viewing time period – 22:34 – 03:52

Well it was time again to perform another TPoint run and adjust the polar alignment. Tonight was all about refining the previous alignment using the Point software which then measures the error once you have 20 points and reports back how many ‘tic’ marks on the mount you have to adjust.

The first run produced an error of +17.8 arc minutes for the azimuth so I had to a adjust the mount counterclockwise 22.8 tics. The error in dec was 8.3 arc minutes so I had a smaller adjustment of 8.6 tics on the altitude.

I then ran a second Tpoint model, again just over 20 points and this time the error was reduced to 12 arcmins for the azimuth but 12 for the altitude so dec. Instead of adjusting by tics now was the time to start drift aligning using PHD2.

I brought up the program, found a start near the Meridian and near the celestial equator and quickly found a guide star since my FoV indicators within TheSkyX now line up. The error in the drift align matched very well the error within the Point model so I adjusted by the number of Tics suggested in TheSkyX. Once done I performed a third Point model of 20 stars.

By this time it was already 1:34am and I had been refining this for 3 hours, the new model told me that I was only 4.2 arcseconds out in azimuth and -2.9 arc mins out in dec. Once again I went back to PHD2 and from then on just drift aligned to refine the error.

This took until 3am when the error was a mere 0.8 arc seconds for the altitude so Dec and 0.1 arc seconds for the azimuth so RA. This was then good enough to take a quick 10min unguided image through the 12″ which is 2.5m focal length. Very impressive.

10 min unguided exposure – note the doughnuts due to it getting light

I then quickly finished off by performing another 20 point TPoint run so I had a model to use tomorrow night so that both Bob and GingerGeek can further commission the two refractors. I will perform a further longer Point run for turning on ProTrack in a few months.

For now it is light, the birds are singing and I ought to go to bed 🙂

Viewing Report 22nd/23rd June 2019 – IMT3 Observatory

Viewing time period – 22:00 – 02:31

Tonight Bob and GingerGeek came over to progress with commissioning the observatory. The task for tonight was to get the Esprit 120 focused and given first light. As the evening progressed there was slight frustration of how long it was taking to sync on a star, in terms of finding it and then being able to sync so we could go back to it. This is because I had been the night before messing with the polar alignment and we have yet to perform a Point run.

It also took some time to get focused on the Esprit due to us setting the maximum extent to the focuser tube incorrectly, falling short of the distance needed at the back focus to get good focus. We then had to go into the observatory and modify the maximum out figure for the Lakeside focuser.

Once this was done focus was achieved and GingerGeek used autofocus within SGPro to get good focus.

A single image was taken to prove it.

Next we need to refine the polar alignment with a TPoint run and then perform a longer Point run to finish the commissioning of the Paramount MEII.

Slaving the Dome (Part 1)

It has been interesting to see if we can automate the Pulsar Dome through ASCOM to slave it to the movement of the Paramount MEII and the 3 OTAs that reside on top.

We originally tried using SGPro and a complicated spreadsheet from Pulsar to record and then model the spherical trigonometry that is needed to make this work. After a number of days we gave up as it simply was not aligning the slit of the dome with the main OTA let alone the other 2 that are piggybacked.

So we are now trying to resolve using TheSkyX Dome Add-On, an expensive piece of software from Bisque that if it works, despite the cost is worth every penny.

Well after putting in some simple figures as stated in TheySkyX user manual over a few pages, we have managed to slave the dome slit to the main scope with ease. It was really very simple and after the mucking about with SGPro and the model information from Pulsar spreadsheet, it just works. I then took a look at the 2 other OTAs and have changed various figures that I will share once all work flawlessly. These figures are to do with offsets for the OTAs from the optical centre of the main OTA. I have asked Bisque to confirm I am changing the right figures and asked how I save them to a profile or alike so that I do not have to re-enter them every time we want to swap scopes to image from. I have also asked for clarity around moving the dome at sidereal using the distance of the OTA to the dome slit figure.

Dome Add-On setting page for configuring the scope offset

At the moment whilst I await their return on the questions, the mount is able to slew around the sky and the main OTA is always within the centre of the dome. The 2 other OTAs if I change the figures in the fields for the offsets also are in the main through the slit, just near the meridian there is a slight overlap but I have guessed some fo the figures so they may be wrong.

More to update later once I have the clarity from Software Bisque I hope.

Almost Completed

So another day spent with Dave and Bob just finishing off the finishing touches to the scope/mount installation whilst Dave messed about pretending to be a brickie and spent lots of time not actually doing any brick work so we think he may now be qualified.

We spent some time tidying up cabling and testing a low light camera for use in the dome at night so we can see what the mount and dome are actually doing.

Now the Chroma Ha and OIII 3nm filters are now installed into the SX filter wheel the only things that remains is to wait for the delivery of a cable (FTDI) to connect to the Optec Flip Flat panel.

Obviously the next bit is working out if the reducer to CCD spacing for the 3rd scope is correct and work out the focuser backlash so we can correctly use SGPro focus offsets for the filters.

Viewing Report 26th/27th May 2019 – IMT3 Observatory

Viewing time period – 23:46 – 02:54

Well after another long day continuing the commissioning of the observatory it was time to test out Bob’s Tak and see if we could get focus. The first challenge was a bunch of devices were not recognised including the Lakeside focusers. It transpired this was due to me performing cable management by the UPS and accidentally pulling the mount power cable out of the UPS, thus no power to anything on top.

Once I got everything running again I reinstalled the Lakeside v1.1 drivers ( not the v2 drivers as they are for the USB version of the focuser), this meant the focuser was then available and connecting on COM 9. Oh and of course both the hand controllers for the Lakeside where physically powered off with their switches that we forgot to turn back on, so that set me back 20mins to figure out.

I slewed to Arcturus and opened up the dome, the dome being slaved to the scope got very close to where it needed to be. The camera was extremely out of focus as it was set to 0, so all the way in, however it also needed another 57mm of adapters to get the camera to focus!

I also noted visually the offset on TheSkyX for the Tak so that later I could move the FoV indicator to match it.

Tak offset, Arcturus centre, Yellow circle and dot telescope pointing

As can be seen above the offset due to the mounting of the Tak on the side of the RiDK is clearly noticeable and we will have to adjust for this offset when pointing.

I then had problems getting the other Lakeside to connect and noticed the Optec Flip-flat panel software was temperamental and required disconnecting and reconnecting if I left for some time and wanted to open/close. So instead I moved to the RiDK to get the pointing for it instead.

Here is the screenshot from TheSkyX for the RiDK so just slightly off for pointing but I have not Pointed yet nor have I adjusted the polar alignment with PHD2.

I then took a quick image to prove it worked with the camera again since we had all the cabling in bits yesterday.

I also noted a couple of other things that I could start to adjust, so I initially kept the dome and telescope slaved, I then went to Arcturus and then disconnected the slaving of the dome and manually moved the small distance to allow the RiDK to be through the slot and then moved a chunk more for the Tak. We will need a camera with night vision to be able to see the slot and adjust for the Tak and Sky-Watcher Esprit 120.

So fairly cold and tired and I was getting up at 8am to head out for a coffee with my friend Paul, I packed up just before 3am to head off to bed.

Viewing Report 9th January 2019 – IMT3 Observatory (Visual)

Viewing time period – 18:31 – 19:20

Well after moving house on the last day of November last year, I have finally unpacked enough boxes and have the house straight enough to find my rather large binoculars (100mm refractors) and set them up in the garden where the IMT3 will finally be built.

Tonight was really about testing out the visibility of the new site and making sure the large binos were working for the following days lecture at Basingstoke Astronomical Society, along with seeing if I could see the comet 46P/Wirtanen that my other friends were looking at.

Screenshot from SkySafari of Comet 46P/Wirtanen location

So it took me a while to find the red dot finder, strap that on with a plastic tie wrap from Alan Lorrain and then align it. Once done then it was much easier to find things. So the seeing was not great tonight and the site is clearly not as good as Sherborne St John, however I could easily make out the magnitude +3.3 star, Muscida in Ursa Major. The comet could not be seen visually with the naked eye, this was due to it being magnitude +10.9 as reported by SkySafari. Once I put my 100mm binoculars on it however after star hoping from the main star at the end of the saucepan, Dubhe, then I could just make out the comet there with Averted Vision (AV). With Direct Vision (DV) I could not see the comet at all.

To test the seeing I also referenced the double star HIP 40734 in Lynx (which is where the comet actually resided) and I could make that out with DV as it was magnitude +9.44 for the main component. Therefore I put my visual ability to see objects on this night at around mag +10. I will add further data to this as I progress my visual astronomy from this site with my binoculars, which are now nicknamed the BFB a bit like Elon Musks rocket the BFR, if you catch my drift ….

IMT3 Starts

On Thursday the 10th January 2019, Ripton Windows, who are also building me an Orangery, marked out for the first time the location of the main slab of concrete that the IMT3 will be built upon. It is with great excitement that a new IMT is being built even if this time it is not manufactured by myself, Bob and Brendan.

I will undoubtably blog about the progress of the observatory here that will house 3 setups for myself, Bob and GingerGeek which will be used by all three of use remotely. The idea is this is a dark site setup not requiring any hands on for most of its use.

The observatory will be a full height 2.7m dome with full automation, both of the shutter and the dome rotation. The equipment within will be accessible from any remote location in the world and with the planned suite of software will automatically close should the conditions require it.

I look forward to giving more details as they come, for now I await the first spade of digging next week as the foundations of the orangery are finished and the observatory and patio foundations are started.