Lodestar – IMT3b Observatory

Viewing Report 20th April 2020 – IMT3

Viewing time period – 20:15 – 23:46

TONIGHTS TARGETS

H56-1 / NGC2903-OS-Ha-300s x 12 – Done

NGC3395-OS-Ha-300s x 24 – no Ha so aborted

M94-OS-Ha-300s x 8 – Done

M85-OS-Ha-300s x 24 – no Ha so ignoring

Flats () Darks () FlatDarks ()

Camera Temp -26℃

WORKFLOW

Cool down scope and dome – done
Turn off Dehumidifier – done
Turn off fans on scope – done
Find home – done
Slew to nearby star to target – done
Select filter and focus – done 74,517 Ha – done
Slew to target and take a test image using Frame and Focus – done
Solve and Sync and then right mouse click on object and Slew Here – done
Setup SGPro Sequence with details – done
Make sure guider connected and calibrate – done
When guiding run sequence – done

Tonight we will take a bunch of Ha images for 4 targets we have been imaging recently with Ha data being provided through the 12″. I have selected the 4 objects in order of passing across the Meridian first. We should aim to get 2hrs of Ha in each, in which case we may need to take the rest tomorrow.

Auto focus run before dark on Ha using 20s subs @ 21:00 focus position is now 74,517 at focuser temp 15.84℃

Autoguiding on 10s with one of the 2 stars in the FoV of the guider for OS12.

@21:17 started taking the first image. Noticed quickly the guiding in Dec went up, so stopped and recalibrated guider. Then started guiding on 8 second subs.

So the sequence is now running and taking frames of the first target in Ha NGC2903 aka H56-1.

After 12 x 300 seconds on NGC2903 I slewed to NGC3395 and took the first Ha image, but unfortunately it was very dim so not worth pursuing. Instead I have now switched to M94 which is currently on the East side of the Meridian. I will take 24 x 300 seconds Ha with no guiding. It will require a meridian flip in about 90 minutes. I will then leave Bob to complete the Ha on M94 for the rest of the night as M85 does not have any Ha within it.

Bob continued and had a little success, cloud rolled in at 23:46 so frame 9 onwards are no good so we got 8 frames in total for M94, we will continue another night. The shutter was closed as Bob did the meridian flip due to cloud.

I tried to take calibration frames the following day at 7pm when the outside temp was 15.5℃, the inside was 18.5℃ but the ASI camera on the OS12 would not get lower than -25℃. I now concur for with Bob and GingerGeek that we should lower the cooling temp to -20℃ for the remainder of the Spring and Summer returning to closer to -30℃ in the Autumn / Winter. For now I had to wait for the temperature to drop outside and thus inside to cool down the final 1℃ to take the calibration frames. By 20:22 the temp outside had dropped to 12℃ and the internal temp to 15.8℃ which was enough to cool the camera to -26℃.

Viewing Report 19th April 2020 – IMT3

Viewing time period – 21:16 – 23:24

So first I could not see any USB devices that were plugged in to the USB hub on the mount. A reboot of the mount fixed that problem. Next I could not auto focus, I did not get to the bottom of that so tried to focus manually best I could. Then PHD2 settings were wrong for the OS12 and the associated lodestar guider, the calibration steps were 100 rather than 400, the min move was 0.66 rather than 0.18. I had taken screen shots before on the blog so changed them back, I am not sure why they have changed. I then managed to calibrate the guider on the OS12, given I have taken off the camera to clean the filters the other day.

@22:15 I started imaging RGB on M94 on the OS12.

The guiding was not bad after calibration. I set to expose once every 8 seconds on the only guide star in the FoV.

What I do need to do is set the FoV indicator in TSX for the Lodestar guider to the correct position to help find a guide star. Else I really should try to guide with one of the other scopes. I am now off to bed, I will leave the scope collecting the rest of the green, 2 left and the final 12 blue. Then Bob will take over imaging for the rest of the night.

Bob took over Green which lost the guide star, so he performed a meridian flip, continued on the Green and then took some Blue. Bob then took some HA, OIII, SII at 5 and 10 minutes for a test. The Ha would be useful for the galaxy as an LRGBHa image. Bob turned in at 2:50am.

I also noticed this morning that the Offset was wrong in the ASI camera profile which was called ZWO camera in the dropdown and in fact was set to 50 rather than 21 for this Gain which was correctly set at 139. I have also changed the OSA12 No Guider profile to use the ASI2 camera rather than the ZWO one, not sure the difference. I have adjusted the setting back to 21 so all the OS12 profiles now use Gain 139 Offset 21 as their standard. If we want the other 2 setting that need changing for each time we run, along with subsequent darks and flats etc would be Gain 0 Offset 10 and Gain 75 Offset 12. For the moment the Darks and Flats etc from last night are Offset 50 so we can only use for last nights images.

Viewing Report 1st December 2019 – IMT3 Observatory

Viewing time period – 19:03 – 21:27

Tonight I wanted to get the PHD2 guiding working when doing a meridian flip without the need to calibrate. A month ago we still failed to get this done, however a little experimenting tonight and changing a single setting has corrected the problem. The setting was the ‘Reverse Dec Outputted After Meridian Flip’ one within the Guiding table of the Advanced Setup, for which I ticked and this fixed the issue.

Reverse DEC output after meridian flip needed ticking!

I then decided to try 2 objects either side of the meridian and that worked manually slewing to each and then guiding. What did not work was the slewing automatically to the object in terms of centring on the screen. It slewed to the star, I could see it on the screen, the first object Almach worked ok, but the second object, Deneb appeared on the screen but failed to centre with the error ‘ Failed to auto centre, aborting sequence’ followed by ‘ failed to centre on object with an error less than 50 pixels’. Plate solving works fine, well at least it comes back with success.

So I tried different sets of co-ordinates from TSX including the Topocentric and 2000.0 sets. Neither made a difference, with 2000.0 data used I still got this set of errors which shows an error in pixels of more than 50 in DEC.

So I decided it might be the very bright object I had picked, star in this case, that was causing the problem. So to further my experimentation this evening I choose two different and less bright objects, M36 and M39, once again on different sides of the Meridian. Success !!

So after fixing this I am now happy to go off to bed early (9:30 work tomorrow) with a job well done.

Clear Skies 🙂

Viewing Report 23rd/24th August 2019 – IMT3 Observatory

Viewing time period – 22:34 – 0

Looking at Vega ready for setting up guide scope

GingerGeek round tonight to align his guide scope, focus it and make sure guiding works. The first thing we had to do though was unplug my camera and then plug his into the Mount Hub Pro due the fuse problem from the last session when it melted through the fuse holder, that will be fixed later this weekend.

Next we slewed to Vega as seen above and took a quick image to see how far out the Esprit 120 is compared to where the OS12″ is pointing so that we can adjust it later.

So it would seem focusing was a bit more of a challenge than we thought. The first thing is we bought an adapter for the guide scope (aka the finder that came with the Esprit 120) but it did not provide enough back focus for the camera. We had a look round the adapters in the dome and found a nose extension for the Lodestar, however it was not a c-mount end to it so we landed up duck taping it on tonight until GingerGeek can bring round his adapter.

The next challenge was not seeing any stars in the lodestar, after what seemed like a long while we came to the conclusion that the picture we were looking at on the screen in PHD2 was not the camera we thought, it was instead the one from the OS12″ which at this point was not pointing through the slit.

After looking through the settings on PHD2 we found a new setting we had not seen before, which seemed to be because we have multiple ASCOM cameras connected.

The symbol is a double arrow and when clicked a drop down list of 4 Starlight Xpress cameras appeared, so we chose the 4th one which was one of the two Lodestars and that worked.

I then adjusted the guide scope in its two ring holders and aligned close to Vega which we had slewed to. Now the guide scope was spot on and the main scope ever so slightly off. This will be solved when we either shim the scope to align with the OS12″ or when we add/change the way in which it is connected to the losmandy mounting plate.

By 12:40am we had the focus sorted for the guide scope and we moved back in doors to connect back to the 2 cameras for this evening, lodestar and main imaging camera and then the Lakeside focuser to start an autofocus run on the main camera.

At 1:20am we were still trying to focus as we had not setup the autofocus routing for the Esprit 120 before, the OS12″ is now fine but this was a new challenge. GingerGeek spend an appreciable amount of time changing the step size and other settings in SGPro to effect the focus routine. Finally autofocus did a great job and we landed up at a focus point of 6225 for the Luminance filter. However there was an amount of backlash and this caused the focus point to not be the same in a one direction. GingerGeek needs to find out where he wrote down the figure we measured for backlash so we can add in.

Good auto focus achieved but with slight error

Next we slewed to the star near the Elephant Trunk, SAO 33570 and changed the filter to Ha. GingerGeek then started an auto focus run for this filter. As it was now late we were missing setting simple things such as the exposure time increase from 1s to 15s needed to actually register any stars to focus on.

Once focused (ish) as we are tired now, we started a short test image run of 10mins subs for the Ha. GingerGeek showed me the Big Status window which is a much nicer interface to your image progress.

We then had a problem with guiding, there were inconsistent rates between the RA and DEC axis. This caused trailing of stars so we stopped the guiding, however the next image although still out of focus showed promise especially given we were not guiding.

10min unguided Ha Esprit 120 (out of focus)

So 3:24am and time for bed.

Viewing Report 10th/11th August 2019 – IMT3 Observatory

Viewing time period – 21:04 – 04:28

So whilst the wind is blowing a gale and branches have come down off of 300 year old oaks where I live, the weather decided to ease as we went into the evening. There were still gusts of high wind but nothing really to be too concerned about for the dome.

Due to more changes on the mount and the polar alignment changes I needed to do a new TPoint run. I first tried to complete a recalibration run that would add additional data, however after a 30 point run the pointing got worse to the point where I was not landing up on the object but several fields of view. So I bit the bullet and deleted the recalibration data and the original model and started again.

It took me about 1.5 hours to run 30 points on the East side of the mount and another 1.5 hours to run the next 30 on the West. I was happy with the results and I turned on some new Terms as I went through. As you select the term you can see the resulting change to the position of the telescope. So rightly or wrongly I used this process a few times when the pointing was either not improving or it just needed to improve a little.

I also created a Supermodel of the data and once again enabled Protrack. I then went to my usual target of the Elephant Trunk to try and get use to pointing to the right object and then imaging it from SGPro. I decided the easiest thing was to use The SkyX to move to the object as I knew I wanted to be centred on SAO 33570 a star in the trunk. I did this and with my new pointing capability since this evenings TPointing, the scope landed up pointing at pretty much the right area. So instead of Sync and Solve I left it at this location for tonight.

The Polar Alignment report produced by TPoint on this new 60 point model showed very little error in either RA or DEC which is a testament to the long hours I put in drift aligning the mount.

At 2:04 am I then tried to cool the camera but it was non responsive……..this threw me for a while then I remembered the other evening having this same problem which probably meant the camera power was not on.I went into the dome to find that was the case and the reason once again was the fuse on the Mount Hub Pro had melted. I cut this off and put a chocky block in for this evening to bypass the fuse, but I did unplug everything else from the mount hub pro whilst there was no fuse there.

Whilst doing this I was reintroduced to nature with a Hornet the size of my thumb bouncing around in the dome. After quickly removing myself from the dome I cam back armed with an insecticide and sprayed the offending hornet. It kealed over and died quickly.

Next I focused and this worked very well, a nice V curve on the Luminance and then I switched to Ha for the imaging, This would be slightly out but I need to find a strong HA source of stars to be able to focus with Ha.

Once again I ran the Image Sequencer to see if this would work given I had made some changes suggested by my good friend Mil Dave to the guider settings in PHD2 and SGPro. However once again I was foiled with some new error messages, I am either getting use to this or possibly very fed up, SGPro may be a great piece of software from a functionality perspective, but it is complex, unintuitive and a pain. The error complained about the PHD2 profile ‘OS 12 Lodestar Guider’ is not valid.

This is indeed my profile and is valid so not sure about this, another thing to investigate when I am not so tired. The follow on message was Could not start the autoguider and connect to the equipment so aborting. This is to be expected.

So I went back to Frame and Focus and too a single 5min shot, guiding on a good star that was in the FoV of the Lodestar off-axis guider. I took a 10min image and then a 20min image.

Looking at the TPoint model there was a nice improvement for where I started with a with an RMS, Root Mean Square of 100 so when pointing the object I am targeting will be within 100 arc seconds of the centre of the CMOS chip, so 1.7 arc minutes, whereas now it is leas than 1 arc minutes out at 57.9.

I then went back to SGPro to try and fix this error as I don’t like giving up. I changed more settings within SGPRo and PHD2 around the error size for the guider to settle, however SGPro was still waiting for PHD to report it had settled even though it was now guiding.

Error message

I turned off both the Settle At and the Settle Auto Guider check boxes. This then allowed me to bypass the whole settling thing which wis is really not that important to me as I manually setup guiding first and now the sequence has started at last!

Finally the guider looks very smooth and the only thing now stopping me from taking some more images is the fact it is 4:28am and I am very tired and it is getting light. So I will disconnect and shut down until the next clear night at a weekend. All in all a very productive night.