Blog – Page 7 – IMT3b Observatory

FSQ85 Flattener & QHY286C CMOS

I’ve taken the plunge and dipped my toe into the CMOS world. Since I didn’t have any OSC experience I chatted with DSW (has a QHY186c) and decided on the QHY286C. This I purchased from Bern at ModernAstronomy who has always provided excellent service.

The issue with APS-C sensors when coupled with the Takahashi FSQ85 is that the edges start to show signs of star elongation, I already see this on my Atik460. This can be corrected with the FSQ-85 flattener (ordered from FirstLightOptics) which has the effect of slightly increasing the focal length but also reduces the back focus from the native 197.5mm to 56mm.

Effective Focal Length	455mm (f/5.4)
Image Circle Diameter	44mm
Metal Back Focus	56mm

FSQ-85 EDX with Flattener 1.01x

This means that I can’t use my existing Atik OAG->Atik EFW2 and Atik460 because it’s total distance is 59mm (22mm+24mm+13mm) so it’s out by 2mm even once you include the filter effect on the back focus. Note – This is also true for my Starlight Xpress configuration.

I do not understand why Atik could not have got to within the 55-56mm range by shaving off a mm here and there 🙁 I may need to replace all Atik gear when I convert to mono CMOS or replace the OAG with a guide scope.

So onto the QHY268C, the OSC CMOS unfortunately has a CAA tilt adapter instead of a direct thread connection. This wastes 11mm of precious back focus giving a total distance of 23.5mm whereas the recently released QHY286M CMOS has a 12.5mm back focus !!!!

Also the QHY268C does not have an IR/UV cut filter in place so you need to buy an additional filter and holder and add that to the cost and factor in the adapter and distance needed …. I’m starting to regret this purchase more and more !

Back to the Takahashi Flattener (TKA37852), the back focus is 56.2mm but we add on the filter thickness as it changes the light path (2mm/3=0.66mm) so ~57mm (56.9mm), the imaging train is as follows :

Adapter	Distance (mm)	Accumulated Distance (mm)	Connector
OU031	2	2	M54(M) -> M54(M)
QHY 020770	4	6	M54(F)
QHY Spacers	14.4	20.4	screw
QHY OAG-M	10	30.4	screw
QHY 020055	2.5	32.9	screw
inc filter	0.6	33.5	–
QHY CAA adapter	6	39.5	screw
QHY268C CMOS	17.5	57	screw

FSQ85 Flattener to QHY268C imaging train

The combined weight is 1365g so I may need to adjust the balance of the scope a little as it heavier than my Atik460/EFW2/OAG setup at 1080g.

Completed – Imaging train ready for first light

I may have to adjust the spacers a little but I won’t know until I have received a 2-inch Optolong L-Pro light pollution filter which is currently on back order from FLO.

QHY268M

The recently released mono version of the QHY268 looks like it has a proper screw face plate with a more acceptable back focus of 12.5mm. This is more reasonable and would allow me to couple a filter wheel and OAG as well not requiring a IR/UV cut filter.

Like SyedT on StarGazersLounge I could go back to using a guide scope and ditch the OAG and then the imaging train could incorporate a rotator :

Component	Distance (mm)
QHY268M CMOS	12.5
QHYCFW3M-US	17.5
M54 (M) to M54 (M) adapter	2
Pegasus Falcon Rotator	18
M54 extension ring	5
M54 (M) to M54 (M)	2
Total	57

FSQ85 Flattener/QHY268M Imaging Train – Credit SyedT

I was thinking of a rotator for the remote Esprit120 which has a generous back focus of 76mm so I should have no problems there but that will be another adventure for the future !

Viewing Report 12th February 2021 – Travel Setup

18:45 – 00:32

Holiday time! Well at least a week off work. It’s been a cold and cloudy Winter so far. So a night where I can get out the travel telescope and setup in the vegetable patch, the construction site of IMT3b is a good thing. The challenge I have is my ribs still hurt somewhat from being broken after an unfortunate accident 4 weeks ago. So I will go careful.

Earlier in the day I had Luke help me setup the equipment in the garden. First the binos to have a good look round.

Altair Astro 100mm Binoculars and APM Mount

Then we setup the Skywatcher Esprit 120 ED on the Paramount MyT.

Lastly we setup a “warm room” temporary in nature and fairly cold I would later find out 🥶 in the greenhouse.

Lovely new table with my cool astronomy chair and MacBook Pro

So the night came and after Pizza with my wife I set off out to the garden to start imaging.

I connected the Polestar camera first to see what my alignment was like after placing the tripod down in a fashion I though condusive to being polar aligned.

This is where polaris landed up which is not bad.

I then set about measuring the difference in Polaris to determine how much I would need to move the scope to align it.

I then fiddled with the altitude and azimuth knobs to align the scope.

Next I slewed to the first object for the evening which was M45, the Pleiades, the Seven Sisters. I started EZCap and look at the focus which was not far off from the last time I was out a few weeks and it is good enough.

I then took an image of M45 to make sure it was in the field of view. I also setup the Planner in EZCap to with the sequence for capturing the data. I set the camera to Gain 7 and Offset 20 with a temperature of -30℃.

I set PHD running and that was when I hit a problem. To cut a long story short, I had forgotten to plug in the ST4 guider cable into the ZWOASI290 camera and then into the Versa plate of the Paramount MyT. Without this there is no successful calibration within PHD. It took me 1 hour to work out I needed a cable and a further 45mins to find it since the move of house. Your IQ really does drop when it is dark and cold!

Eventually the calibration completed once the cable was fitted and I could start to see the gusts of wind in the data. I set a sequence running for M45 and was impressed with the results. I took 10 x 90s and 10 x 180s.

I then switched targets and headed over to M42 and M43 along with the Running Man nebula, also known as SH2-279 and NGC 1977. I took 30 x 60s, 30 x 30s and 10 x 180s.

Next and what would be last on my list tonight was M35 along with NGC 2158. I took 10 x 90s and 10 x 60s starting around 23:45.

Now the clouds at a high level started to roll in. So I decided to take some Flats and then take the darks tomorrow morning.

So I packed up and had one last look up at the night sky.

CPRE Star Count 2021

The Campaign for the Protection of Rural England (CPRE) was running it’s annual star count for 2021 from 6^th – 14^th February.

Basically in order to assess the effect that unnecessary man-made light pollution has on the quality of our life’s the CPRE want people to count the stars they can see within a box formed by the brightest stars in the constellation of Orion (not including the four main stars that form the box) and submit their observations.

A couple of us arranged to get together remotely and count the stars we could see at 8pm on 10/2/2021 when Orion was near it’s highest point in the South. Of course at this time of night the light pollution is also fairly high 🙁

Suburban Sites

Observer	Star Count
Jim	9
GeekBoy	10
GeekGirl	11
Neil	12

Observation – 20:00 10/2/2021

The SQM (Sky Quality Monitor) reading for our (GeekBoy/GeekGirl) location at that time was 19.92 mags/arcsec² which places it around a Bortle class 5 sky (NELM 5.6-6.0). Of course later on during the night, once the causes of light pollution subside I normally get a reading of 20.6 mags/arcsec².

Observer	Star Count
Giles	9
Stephen et al	13

Observation – 20:00 12/02/2021

Rural Dark Site

Dave got out with his family to star count from his rural dark site and the comparison is stark ! There may be an age effect on the eye sight here as they are from the same time/location but either way it’s shows what can be seen in the absence of excessive light ingress.

Observer	Star Count
Dave	23
Daughter & Boyfriend	27

Observation – 21:40 10/02/2021

Well that was a bit of fun and a welcome distraction in the current never ending lockdown – thank you guys !

Lakeside Focuser broken (23rd Jan)

So whilst Dave was in his garden using the binoculars and failing down holes in the process I was setting up to relearn how to take images ….. it’s been that long and the weather hasn’t helped.

So all was going well except that the Moon was bright and right near the winter nebulas. Even how bright the moon was I decided to use the time and practice using the Monkey Head Nebula as my target.

The tripod was levelled and the iOptron CEM60 polar aligned, the scope was balanced, the Atik460 CCD was cooled (-25℃), OpenPHD calibrated, the plate solver completed and the successfully sync’d and . The first step was to autofocus on a decent bright set of stars before the imaging run.

That was when the night was over ! SGPro set about running it’s autofocus but strange things were happening. SGPro was reporting that the LakeSide Astro focuser position was changing but the star HFR profile was not changing and the V curve remained flat. Since the focuser position was “changing” I did not think to go out into the garden with a red torch for an hour.

Upon inspection it was fairly obvious why it wasn’t working and inside the issue was proved to be a disconnected wire on the motor port.

Hmm …. I wonder what the issue could be !

I thought it would be prudent to double check which of the two spare connectors the wire came from and indeed it is the top one.

Removing the heat shrink outer and you can see that there is barely any wire left since the majority of it was left in the solder when it broke off. This will require a wire extension and the old solder with the remains of the wire removed first before new solder being reapplied.

View of full cup connector with solder and empty cup connector

So since I’m really bad at soldering and I was worried about having to replace the whole unit (£90) I asked a friend who is fairly handy at this to perform the fix for me.

Viewing Report 23rd January 2021 – IMT3

20:20 – 22:11

It is clear! It has been some time, at least for me, when it is clear at a weekend. It is cold. Skippysky.au/europe tells me it is good seeing, the transparency is excellent and the Jet Stream is way South of the UK. The Moon is around 70% and the local temperature is -2 degrees C with a slight frost already. I have come out with my 100mm binoculars to star hope around.

I had just finished a call with the BASEG society, most whom I had not seen in some time as we are still in lockdown. I came out to a Moonlit garden with a carpet of ice twinkling and crunching as I walked. It is nice to see this new garden at night and get a feel for where I may observe in the future.

I setup the binos in the vegetable patch next to the building works for IMT3b. Not one but twice I stumbled down the trench dug for the cables, so I must be more careful. I then pointed the binos at the Moon and took a look.

The view was splendid. There is something wonderful about seeing the Moon through binoculars and seeing just how deep you can go. Clavious was crips and easy to spot as was Tyco. I spent some time here and then Luke came out to view. We looked at the Moon first then I moved to M42 which, whilst washed out by the Moon, was still bright enough to see the distinct wings. The trapezium was also very clear indeed.

After a call to Gingergeek, who incidentally was having problems with a disconnected wire in his focuser, I moved onto M45 Pleiades to identify each of the 11 major stars fro Atlas in the West to 18 Tau in the East. Electra, Merope and Alcyone were all rather bright. I then swooped across to Aldebaran before moving across to Mars, the bright planet a small circle in the binos. I then star hopped to M33 to find the surrounding stars without being able to see the galaxy itself.

Mark Radice then called and we chatted about his C11 and the Sinus Iridum mosaic he was imaging tonight whilst sitting in his warm room. We spoke about things to look at and Mark remotely star hoped me to the double cluster, which surprisingly could be seen naked eye, even on this bright Moon night. He then guided me to Uranus which I found in a pattern with 2 other stars making up an isosceles triangle with Uranus being distinctly blue to the bottom right. I was then fairly cold so bid farewell to Mark and headed off indoors to warm up.

IMT3b – Build Part IV

1st January 2021

So the cable is installed in the trench visible here before I laid the ethernet.

It runs all the way across the garden to the observatory very neatly.

When it reaches the observatory, enough cable is left to feed through there pipe later and the end is terminated in an outside socket. This will be later daisy chained to several internal plug to the observatory and the outside power fixed to a new brick pier that I will build.

The next job was running the ethernet from the house. I purchased Cat6E as I also wanted to run cable to several places around the house that would require PoE (Power over Ethernet) which allows one to fix an access point without the need for an additional power supply. I started by preparing one end of the cable to be spliced and crimped given I had not done this for a few decades. I purchased the crimping and test equipment online and it seems to have worked well.

Then I laid out the wires in the correct colour format. The tricky part is getting all the wires to stay flat after twisting round each other to get them in the right order. Then to make matters worse you cut them short to much the connector on and the cables self align in slots.

Cat6e Wiring Diagram - Train Wiring Diagram - gsxr7500.deco-doe5.decorresine.it — Cat6E

The final end looks like this.

Out of interest I have posted here the access point I purchased that is PoE, I simply love it, although nothing to do with the observatory per say apart from going into the kitchen in this instance at the same time as running the cable to the observatory.

The AP does require a switch or hub or router that supports PoE, unfortunately none of the hubs that come from the major broadband suppliers ship any so I purchased the TP-Link switch that does.

To conclude this part here is the single Cat6E cable going into the AP.

So then I set about running the cable from the observatory site across the garden with an RJ45 connector ready and waiting under the tarpaulin at the vegetable patch.

Ethernet CAT6E cable installed long with power.

I then terminated the first leg of the cables journey in the woodshed where the power is connected (I plane to spur a connection to the planned Summerhouse from here in the Spring) and setup my laptop in the vegetable patch to test the connection which worked!

Before I get to the final piece of ethernet running from the woodshed to the workshop, I wanted to run the large length of cable from the workshop to the Snug. I am fortunate that a BT cable had been run back in the 90’s to the workshop when it was used as a business office. Given I had no need for a landline in the workshop I decided to use the BT cable to pull through the ethernet down the length of the underground pipe between the workshop and the house, again I am very lucky it was there!

I started to feed the cable through along with a new piece of rope I found in another duct! But I quickly found a break in the pipe located under the steps leading into the workshop.

After hours of pulling and pulling back the other way, then more pulling, my daughters boyfriend Luke (small mercies for Lockdown he currently lives with us) retrieves the ethernet cable taped to the BT cable some 100ft away.

This is the BT connection rats nest at the back of the house who’s cable I repurposed then removed, next to a bunch of electric connection boxes for outside stuff!

The saga for ethernet does not stop there, but nearly! We pulled through the rest of the cable and tacked it up the wall on the right and then along to the door where we spend hours drilling and hunting for the cable in the loft………..

Darkness falls as we finally pull the cable through into the house and into the Snug.

Ethernet cable into the loft and the house.

Here is the tight loft space where the cable runs through.

The final leg was dropping the cable into the Snug where the fibre terminates in the house from the loft. It snakes it’s way around the perimeter of the house inside the loft (I have a chalet bungalow) which took about 2 hours!

Main ethernet connection to observatory!

Fortunately I have the most understanding wife in the world who is very supportive to have her husband spend hours in the loft with a cable.

IMT3b – Build Part III

22nd December 2020

So with the site prepared I had one last check of the levels as the ground slopes away to the right thus meaning I needed to adjust the former for the central block. The dome segments can be seen resting in the background. I also used a large bag of stones to hold the former in place.

Next I cut a hole in the former for the pipework that will take the electric cable and ethernet from the house. I used some old downpipes and kitchen waste pipe I found lying around in the garden.

Here is a closer shot of the pipework that shows a 90 degree angle that all be flush with the finished floor.

Now I had to prepare a trench for the cable running from the observatory to one of the sheds across the garden. So GingerGeek and I set about digging 6″ down where the cables would lay, eventually to be covered by a slabbed path. The digging took hours, hitting rubble including glass in the ground and offending chunks of flint.

About 70 feet trench across part of the garden

Down to the left as the ground slopes away and towards the observatory location, we dug the trench round the corner. The cable would have to run under large rotes and as we found out a large sleeper buried in the ground across the opening to the vegetable patch.

Turning around standing with your back to the vegetable patch where the observatory will be sited, you can see the trench running off towards some outbuildings/sheds and a planted area that I would have to tackle next as GingerGeek had to go do some chores at home.

So it took almost as much time digging this section out as it did getting across the expanse of lawn. Routes from the Sycamore (left) and countless plants made this hard work. I then managed to get to the trellis separating the planting from the 3 sheds on this side of the garden, which I would need to go under.

Around the other side of the trellis it was very cosy to work in the tight space, old wood still awaiting collection by the previous owner meant digging was difficult, also the land raises up quite a bit this side so I had to dig the trench deeper. The hole I managed to create is shown by the red arrow. Again lots of building rubble had to be removed and I landed up on my hands and knees in the trench digging with a trowel.

So I had made it to the shed. Now it was dark and I had to wait another month before Steve the electrician would be able to fit me in. When he arrived and the armoured cable was laid and fed under all the roots, he made the connection in the existing fusebox in the shed.

Then it ran down the wall and out through a hole that was serving the existing power feed from the workshop. The woodshed is in a dire state and needs replacing, but will serve as a hub for equipment until such time I get around to it.

Next I will share where the power and ethernet cable runs and how I installed.

IMT3b – Build Part II

2nd December 2020

So now the work begins. How to turn a vegetable patch into an observatory. The first thing any good person does when moving into a house is perform a harvest! So we set about harvesting and found some rather large parsnips (which we have been having every Sunday lunchtime since) 🙂

Once done, we removed the edging boards and marked out the dome diameter using the stakes we found in the garden.

Once done I left Luke to dig the rest of the dome base out with a little help from my daughter and as you can see digging in a vegetable patch is rather easier to start with than hard ground due to years of using the land.

Dome base dug out….but what about the pier hole?

Okay, so that’s the dome base which is a nice 6″ deep. Next, which was a slightly bit more problematic was to dig out the pier base through chalk to a depth of 65cm x 1m wide. Yes I know I am mixing my scales but that is because I can 🙂

I then had to wait several weeks for the weather to improve before I could start creating the former for the hole.

I must add at this point, that despite building and installing many domes before, I sought out the experience as one should, of another astronomer and friend, Nigel, who sent me a well prepared document of contracting a concrete base, that I have used as extra guidance on this dome build.

View from above with locally sourced (in my ground) flint to be used as sub base

Next up will be more preparation for the foundations and connecting the electric and ethernet from the house some 100m away the way I have to run the cables!

IMT3b – Build Part I

21st November 2020

So after the shortest time in a house, I have now moved to a much better astronomy home, surrounded by fields and forests, ancient woodland and with some of the darkest skies in the North Hampshire Downs. I am fortunate in my location, however less fortunate that the build of this observatory, unlike my other observatories is happening in the middle of a pandemic of Covid-19. This as you will see makes it extremely hard when you can’t have astronomer friends over to help with the preparation and installation.

The move started to with the dismantling of IMT3 and in the final days at the previous house we dismantled the dome, at least at the time I could have some friends over to the garden to help with Mil Dave, Alan and Shane lending a much needed hand.

So on a quick dismantling, which was much quicker than constructing the astronomers put the dome segments on the lawn 🙂

However as I found that night when a storm front came through, which caused me and my daughters boyfriend to get up after midnight to secure the dome segments in a more wind resistance piece of the premises.

The following day Luke has had his first angle grinding lesson to take out the remains of the bolts and plugs which to be honest I think he really enjoyed.

Then the moving day came and I put all the important scientific astronomy equipment in my old Landy to make sure it got there safely.

whilst the rest of the observatory went in a further truck kindly supplied for free by our removal company who are the best removal company ever! Thanks Camberley Removals!

By mid November, some 4 months after we accepted an offer on the house I landed up with my new more astro friendly observing location surrounded by fields.

Next up is removal of the local vegetation and preparing the ground for concreting.

Jupiter/Saturn Conjunction Christmas Eve – 24th December 2020

The most funny thing about moving to a new house is assuming you have understood your horizons correctly, well at least I found it funny when I got it wrong. After several attempts to catch the conjunction, traveling out to a nearby field with low horizons, Christmas Eve was no difference. I had set off, this time with the Esprit 120 and QHY168C and on arriving at the location realising that the weather was too cloudy to grab the conjunction.

So off I went back home. I decided to wonder up the garden to see if the weather had cleared when I returned, to find that not only was there a gap on the clouds, but also I could see Jupiter !!! This meant only one thing, that my South West horizon was not +15 degrees but actually +4 degrees! Wow that is good and lucky.

View South West , observatory is going to be in front of the foreground trees

I ran back to the car and started hauling the travel scope to the building site of IMT3b which is currently a vegetable patch, this is around 200 feet away from the car part way down the garden. It took 5 trips to move all the equipment, good for my Apple watch exercise rings, not so good for the setting of the conjunction of Jupiter and Saturn. By the time I setup and slewed the telescope round the pair were setting behind the ancient forest in the distance but I managed to snap a single image! Perfect.

Jupiter and Galilean Moons with Saturn below – 120 Esprit and QHY168C

Jupiter/Saturn Conjunction Eve – 20th December 2020

GingerGeeks Viewing

The weather forecast suggested that this was the only clear night for some time and the planets were low in the sky. So GeekGirl and I wondered if Jupiter/Saturn were visible from the front of the house to the South-West or if we were going to have to traipse over to the muddy farm fields to view the conjunction.

Conjunction View Facing South – Credit stellarium.org

Luckily for us even though they were less than 10º altitude we could see them both between two houses from the front drive. We quickly got some warm gear on and setup the binoculars and the kiddy scope (Sky-Watcher Heritage 150P Dobsonian) on a camping table.

We quickly got Jupiter/Saturn in GeekGirl’s binoculars (Celestron 20×80 SkyMaster). The pairing although not as close as they would be on the 21^ststill looked nice. The rings of Saturn were discernible and the four Galilean moons were visible in this modest setup and I’m sure the view would be have been better in Dave’s monster binoculars due to the aperature.

Approximate view through 20×80 Binoculars – Credit stellarium.org

In order to get the focus for the planets I used the Heritage 150P on the near half Moon (47%). The views of the craters on the terminator along with the shadows were amazing, we could see the centre peaks of many of the craters.

View via Heritage150P/Super10 eyepiece – Credit stellarium.org

I wonder what they looked like in Dave’s Sky-Watcher SkyMax 180 Pro ?

Our next-door neighbour popped out and we invited him to view the planets and the Moon. I think he was impressed but everyone reacts differently to the experience.

Once we had both wondered over the Moon, checking out the mountain ranges and the changing shades of grey for the Mares we turned to viewing the conjunction in the 150P using the standard eyepieces (SW Super25 & Super10) that came with the scope.

View of Conjunction through Heritage150P – Credit stellarium.org

We could see all four Galilean moons with Io being placed close to Jupiter’s limb. The division in Saturn rings was visible and GeekGirl could glimpse Titan so she was happy. All in all a pleasant experience, which is rare in the current human malware situation. I finished off the evening with a Brewdog IPA ….. bliss !

Dave Shave-Wall viewing

Start time 3pm – End time 6pm

After deciding that I could not get the conjunction of Saturn and Jupiter at the new house, I spent the best part of 40 minutes packing up the travel scope to travel locally to view the conjunction. I set off to view about 1 mile away across a field with allow horizon. I took my Mak180 without the Barlow and the ZWO290MC on the Paramount MyT with the Berlebach tripod. On arriving at the side of the road on the narrow country lane in North Hampshire, I was just about to setup when I realised not only had I forgot the travel car battery, but also the laptop. After a few expletives and a good old English, “I cannot possibly believe I did this, oh well carry on”, I jumped back on the Landrover and set off back home to retrieve the important parts. On arriving back home I ran up the garden to the shed for the battery, grabbed the laptop and jumped back in the car as time was against me for capturing the pairing before they set below the local horizon about 6pm. It was not 4pm.

I arrived back at the field and quickly set about fitting together the mobile setup for the 2nd time!

This time I settled the tripod and mount up in quick time, slide the Mak180 with its imaging train into the Losmandy Versa plate and connected the Mac. I manually aligned on Jupiter which by this time I could see with my naked eye, synced the scope and started the imaging software. After a few back fourths I found Jupiter, however Saturn was nowhere to be seen. It soon became apparent that my field of view FoV indicator on Sky Safari 4 was not accurate and indeed both planes on this particular day would not fit in! So rather than waste the occasion I shot some view of Jupiter and then slewed to Saturn for the same.

I then packed the setup away, but before heading off grabbed the Canon 6D with the 100-300mm lens and grabbed a few exposures. My first attempts were not good, having not used the camera for some time and forgetting how to set the correct exposure. After a while I grabbed a single good frame, over exposed to see the Galilean satellites.

Jupiter and Saturn near conjunction Canon 6D 100mm

Jupiter and Saturn near conjunction Canon 6D 300mm

Jupiter and Saturn near conjunction Canon 6D 300mm Cropped

I would attempt another go with the larger FoV Esprit 120 a few nights later.

ExoClock First Publication & video session

Tonight the ExoClock team based at UCL which is part of the ARIEL space mission held their last meeting of 2020 where they discussed their recently published paper on the arXiv pre-print server.

Our congratulations to the whole team and we look forward to continue working with you in 2021 – Merry Christmas to you all !

Optec Flip-Flat Service – Vendor Review

So during the ongoing Human Malware situation we have been concentrating on imaging asteroids, comets and more recently performing exoplanet measurements on the 12inch RC than long exposure deep sky astrophotography.

Astronomy is one those hobbies that is for most part is sole activity for the dark early hours of the morning and these days is usually done remotely. It was therefore disappointing that when one of the team went to use the Sky-Watcher Esprit 120ED for a night of astrophotography and found that he was unable to open the Optec Alnitak Flip-Flat. As the lockdown and travel restrictions progressed due to the initial wave of the human malware situation the issue was soon forgotten as we continued our focus to performing exoplanet observations on the 12inch RC for the ESA Ariel Mission.

Now that IMT3 has been decommissioned ready for it to be reborn as IMT3b at it’s new rural darker sky site I decided to take the opportunity to retrieve the FlipFlat and diagnose the issue at home on my desk.

Using the Alnitak controller software, I could hear the motor running but it never seemed to complete the close or open. All it continued to display was the TIMEDOUT message as shown below.

I sent an email off to the vendor I purchased it from but after a month I got no reply. In the hope I would not be left with an expensive paperweight I reached out to Optec. After quite a few weeks of getting no reply I was pleasantly surprised to receive a message from Jeff Dickerman (President) of Optec. Jeff apologised for not responding earlier and offered to help resolving the issue. The error message seemed to be a known issue and it was generally an easy resolution which required taking the box apart. Jeff sent me instructions on how to take the unit apart and fix the problem.

You’ll see the motor is attached to an internal wall with a modified shoulder screw and stack of Belleville washers. These spring washers are used to allow the arm to slip when someone grabs the lamp and physically tries to force the cover closed. Unfortunately they can also allow the arm to slip during an open or close operation which leads to that dreaded “TIMED OUT” message. Optec have redesigned the stack a bit to eliminate this issue going forward.

To correct, you might be able to adjust the washer stack by removing the lock nut and sliding off the washer stack to the pivot arm. Check carefully to see if the shoulder screw protrudes beyond the pivot arm. If so, rather than installing the cork washer next, install a 5/16” ID washer first to cover the exposed shoulder. Next add the cork washer and stack of Belleville washers. Finally screw the lock nut back in place and tighten while holding the shoulder screw near the motor (this is important to avoid breaking the internal motor gears).

In the end I decided to courier the unit back to Optec for repair as I did not want to render my unit completely useless in case I made a mistake.

I’m extremely grateful to Jeff, Tina and the team at Optec for all there help, patience and understanding. I’m a very happy customer and the flip-flat will be rejoining the Esprit120 when the IMT relocation is complete at it’s new rural location. I can then do a Homer Simpson and annoy Dave with “Flap goes open, flap goes shut, flap goes open ……”

IMT3 is dead, long live IMT3

So we started the decommissioning of IMT3, dome and all ready for the move to a new darker site location. The new incarnation once installed will be known as IMT3b. As part of the process the Esprit120 will be relocated to a separate pier mount in a RoR shed to be known as IMT3c.

Viewing Report 18th September 2020 – IMT3

21:59 : 00:11

Decided to have a quick look out before moving house, given it was supposed to be cloudy and there is a bit of a clear spell. I have decided to just take a look at a few objects. First up is the Cheeseburger Nebula NGC 7026.

NGC7026 Cheeseburger Nebula 10mins Luminance

Next up is IC63 which is a ghost nebula that Tim imaged the other night, I want to see what it looks like in my 12″ vs his 10″. The first thing I noticed was in the guider window that the reflection of the bright star Gamma Cas caused an interesting image.

Next I am going to go after M110.

I have now slewed to M32 just below.

The last object of tonight and then off to bed so I can be up to help Bob concrete IMT4 tomorrow is NGC 508.

Exoplanet HAT-P-1b (17/9/2020) – IMT3

20:24 – 22:43

Imaging with GingerGeek for another exoplanet. This one starts its pre-transit at 23:55 and should just about be on the point at the meridian where we can perform a meridian flip and then image all night.

We like to make sure we have the right star field so actually having a photo from the exoclock website helps. Tonights candidate is the dimmer star to the left of this pair.

The star is a magnitude 10 star in Lacerta. Unfortunately despite the forecast it has just clouded over, here is what we would have been imaging.

Exoplanet HAT-P-32b (14/9/2020) – IMT3

So the evening started well, I had logged into IMT3, got the dome ready, TheSkyX/SGPro software was up and running, CMOS camera was cooled and I was already syncing on a bright star even though it was still twilight.

Dave and I had chatted the previous night and had settled on HAT-P-32b in the constellation of Andromeda. The reason was due to the target position in the sky, the time of rising and setting was before the rise of the sun so we could get a full ingress and egress and no meridian flip was required.

Then the gremlins started to play havoc with our efforts and I was having major issue with guiding to the point that I was going to give up as the issues were eating into the desired 1 hour egress monitoring time period. Dave joined the session to help resolve the issue and we managed to start imaging about 10 minutes before the start of the transit.

Dave had to go to bed due to work commitments but I was determined to get the full set of observation and run it through the HOPS analysis software. It was an uneventful night interspaced with music, movies and hot cups of tea.

Once I had transferred the data over the internet to my server, performed the analysis and sent the result to Dave it was 5:30am so I crawled into bed around 6am.

Viewing report 12th September 2020

21:03 – 05:39

Bob, Dave and GingerGeek playing with the Tak 102 this evening and just image for 2 minutes on various targets.

Slewed to the Double Cluster first.

Focus position was 564 from the last time we used it a long time, it is now 578.

Took a 2 minute exposure

Slewed to M75 the Little Dumbell. Needed to take a 5 min exposure to see

Slewed to M34 Open Cluster.

Slewed to NGC 1023 a barred spiral galaxy. Took 5mins exposure at 22:12.

GingerGeek went off to bed whilst Dave and Bob continued.

Slewed to NGC 1260 a lenticular galaxy in Perseus.

Slewed to NGC 1545 an open cluster but it was behind the house.

Slewed to IC 1848 the Soul nebula.

Slewed to Heart nebula.

Slewed to IC 1831 an HII cloud.

Slewed to IC 1795 nebula.

We found at this point that some of the images were trailing at 2 minutes in the East so we started to use guiding.

Slewed to NGC 1245 open cluster. [not imaged]

Slewed to NGC 1220 open cluster. [not imaged]

Slewed to NGC 1528 open cluster at 23:37

Dave went off to bed whilst Bob continued.

Slewed to IC 1795 Nebula.

Slewed to IC 1831 Nebula.

Bob then slewed back to a number of the objects as they had trailed including, IC 1805 Heart Nebula, IC1848 Soul Nebula, IC 1260, NGC 1023 barred spiral, M34, M76, Double Cluster

Mars at 1:47am

Slewed to M31

Slewed to M52

Slewed to NGC 457

Slewed to IC 1590

Slewed to NGC 7789

Slewed to NGC 129

Slewed to NGC 225

Slewed to IC59

Slewed to IC83 [no image]

Bob completed imaging at 05:39am

Exoplanet HAT-P-6b (5/9/2020) – IMT3

Session period 19:00 – 01:18, transit start ~23:06 and end ~02:37

Before I move house, we are going to try and grab another exoplanet or two or possibly three…..we’ll see. Tonight whilst it is currently clear and due to cloud over by 1am, we will go for HAT-P-6b that is on alert from Exoclock.

The transit end time is after it is due to cloud over but we may be able to get the start of the transit and some useful data to possibly half way through. So I have opened the dome, started to cool the 12″ down and slewed to a magnitude 4.29 star in the vicinity of Andromeda called HIP 116631 also known as 17 Iota Andromedae in the Flamsteed catalogue so that I can slew and centre on the object when it gets dark.

I’ve now manually centred the star due to the brightness of the sky still and synced in The Sky X

I’m now waiting for a bit more darkness to perform the first focus run.

At 20:31 I performed a focus run on the mag 4.29 star with the red filter and got position 63007 @ HFR 5.2 and temperature at the focuser of 17.28℃.

I have performed another solve and sync as I had left the scope running for a while without guiding and the star had moved slightly.

I have now taken a quick 20 second exposure of the target to confirm it was the right star as per the star chart from the Exoclock website and it was.

I have started guiding on a nearby star with PHD2.

HAT-P-6b rising from the East as can be seen in TSX.

So here is a 2 minute exposure of the target. I tried 60 second but given I am running Gain 10 Offset 10 the maximum pixel count for the centre of the star was 1,648 out of 65k. So a 2 minute exposure produces 9,488 which is still low but I will continue on the low side for now. 1 hour before the transit is in about 45 minutes so I will wait then start gathering data.

So we’ve started and set to run for 5.5 hours, this means a a meridian flip in 4 hours time so I will need to stay up until 2am, perform the flip then head back to bed.

The clouds have started to roll in, however so far we have been lucky and our star and planet are just outside the bank of cloud …… but for how long?

So it finally clouded over around 1am although the data for the past 20 minutes is suspect, so I hope we at least have the first half of the transit.

Exoplanet HD189733b (18-19/8/2020) – IMT3

Session period 21:00 – 23:57, transit start ~21:16 and end ~00:05

Started with Lum autofocus at 21:17 but on changing to the Red filter the HFR rose to 8.5 so refocused on Red at 21:20, position 60789, HFR 3.97 at 21℃. The change in HFR was more likely the warm sky and seeing conditions.

Restarted imaging at 21:39 at new Gain 10 and Offset 10 with a 15 second exposure to get the exposure down well below the 65k max to around 35k. The target star is a magnitude +7.69 so the initial Gain 139 Offset 21 and even Gain 75 Offset 12 were too high even at 10 seconds exposure.

We started with no delay in between the exposures until the start of the transit, then decided due to the large amount of data (35GB) being collected we should put a delay in which we did of 60 seconds. In hindsight we should be placed a smaller delay period in 15-30 seconds to allow us to gather more data points for the transit period. We have emailed the ESA team to start a conversation on planning exposure/delay settings for transits.

We then finished was forced to finish before the projected transit was completed when the clouds rolled in, and took Dark, Bias and Flats frame at Gain 10, Offset 10 ready for the analysis software.

After reviewing the data and the monitoring graphs it is obvious that the less than desirable Sky Temperature showed it was not truly clear. Below is the effect of high haze and cloud passing across the sky during our observation session. It should be noted that we have not had sky with a reading <= -18℃ since mid July.

Not a truly clear sky during the transit

How much impact this has on the observation and measurements we will discuss with the Exoplanet team.