Tonight I plan on setting the 12″ imaging M94, a Messier galaxy in Canes Venatici.
I slewed to nearby star and focused using SGPro after changing a couple of settings in the step size and amount of data points to be used, I set step size to 100 from previous 1000 and data point to 5 from previous 10 and got a much better focus. Focus landed up first time around at 738840
SGPro Autofocus settings changed
I had tried to get @focus working in TSX but it would fail every time on the galaxy with not enough stars. This meant I could not use TSX to solve and sync to centre M94.
SGPro autofocus
I then tried to centre with SGPro and that also failed so instead I used TSX to connect to the camera and manually moved M94 to the centre of the chip. I ned to get the local plate solver working as it was not running.
@ 20:32 I took an initial 5min sub to see what the image would be like after setting PHD2 guiding running.
5 min M94 sub
@1:20 and after gathering 3 hours of data I moved to other side of mount so meridian flip. I refocused as it had drifted a lot. I now need to consider setting up focus move for temp as the focus shift is dramatic. I also changed PHD2 Hysteresis setting to 0.20 from 0.10 as the PHD was having problems guiding.
I struggled to find guide star and landed up exposing for 15s and then having to increase, possibly needs recalibrating on this side of the mount. But also I need to find a brighter guide star by moving the mount offsetting the galaxy. The other way is using one of the piggy backed scopes which I may do next time.
@1:43 the dome closed, not sure why, might have been high cloud but probably because the WSX software lost contact with the WSX hardware. I did a reset and reconnected and then it was fine, but as the dome had closed I packed up with 3 hours of Luminance data on M94. I now need to take flats on the morning.
Single 5 min sub stretched in PI
Learning’s for next time……….
Update the SGPro Equipment profile with the changes for step size and data points for autofocus
Make sure the local plate solver is working and online at localhost
Review Anydesk bug that changes mapping of keyboard
Check out why WSX is loosing connection and shutting the dome
Work out how to use temperature compensation for the focuser in SGPro
Flats from the following day at the same focus point
Slightly hazy right now but I have opened the dome up and turned the cooling fans on the 12″. Slewed to Atik, a mag 2.8 star in Perseus and aligned the scope.
Atik mag 2.8 star in Perseus for alignment
So the star was almost in the centre when I slewed the scope to it, a slight tweak and now synced on it centrally. The Hitec Astro weather station reports slight haze
Hitec Astro Weather Station showing haze
Gingergeek installed a new Intel Windows small form factor computer recently in replacement for the RPi so we could run the AllSkEye software and see if the loss of one of the colour channels was software or hardware. Here is tonights image, which still needs colour calibrating during the day.
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.
Error message failing to centre
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.
DEC Error when centring
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 !!
60s uncalibrated guided M39 exposure
So after fixing this I am now happy to go off to bed early (9:30 work tomorrow) with a job well done.
First thing to say is this is a very long blog, much went wrong tonight before it went right and thus I selected to record as much of the problems here as evidence later if I have the same problem or others indeed do. Tonight I am imaging M76 a planetary nebula in Perseus known as the Little Dumbbell. This is my first real object to image through the IMT3’s 12″ scope. The weather looked good and a quick look through the All Sky Camera showed a clear sky with Vega shining bright overhead and a slight glow with the Sun still setting to the West.
View through ASC
The first thing I needed to do was to slew to a bright mag +2 star, in this instance Caph in nearby Cassiopeia and centre and sync the scope which I did through TheSkyX (TSX). I then slewed to a magnitude +9 star (SAO 21164) nearby so that I could perform an autofocus through the OIII filter using SGPro. The best fit was 73,914.
Auto Focus Achieved
I then took a single 60s exposure just to make sure the focus was right, the stars coming in at around Half Flux Radius (HFR) 4. Meanwhile the camera cooler was running at -20℃ and 28% so I lowered to -28℃ at 60%. It should be noted that every time I perform a closed loop slew in TSX and the camera connects, the camera then looses the information of its status in SGPro and the only way to resolve to disconnect and reconnect. I again will note this is the TOSA User Guide.
Focus image on Mag +9 star
Then I slewed to M76, which on first inspection was still being my neighbours house. So I waited for a while longer and around 21:10 it appeared above the roof for its polar orbit around Polaris. I took a quick image with SGPro of 60 seconds through the OIII filer to see where I was pointing, given I only have a 60 point TPoint model (I need 300 for the best pointing accuracy).
M76 slightly off target
So given I was slightly out I selected the Luminance filter, went back to TSX and performed another Closed Loop Slew and then synced the scope for good measure. The resulting image through TSX and then through SGPro showed a perfect improvement.
On Target
Before imaging I went back to look at the PEC as Bob had mentioned not being able to image for very long on the Tak FS102 after we had taken it off, added the adjuster plate, reattached and added some weights. Not surprisingly the TPoint model will need redoing, however I noted the PEC was turned off, maybe I had not saved the last time I enabled. So I reenabled and saved.
PEC Now Re-enabled
I then went looking for a guide star with PHD2, however even with 10 seconds I could not see one. I looked at TSX and indeed the Field of View (FoV) indicator for the guider showed a fairly barren piece of sky with barely a magnitude +11 star visible.
Guider FoV – bottom right square is fairly limited in stars
Blank guider image …..
I performed a quick check of the SQM and it was reading 19.37 and the Hitec Weather station had a reading of around 25 meaning between Haze and Clear. Another quick check of the ASC and that was showing clear. So either I had to move the scope to find a guide star or I could image without guiding……so the only way to tell was take a quick 5min image and see what it looked like.
SQM reading
Hitec Astro Weather Station
Trailing stars
As suspected the resulting 5min image showed trailing, not surprising given the TPoint model is out so I decided to guide. I slewed around trying to find a decent guide star but nothing came up, literally nothing, which then got me thinking this was not right. So I checked a bright star in the FoV for the guider, still nothing. So I then disconnected the camera and checked the settings and there it was, the setting was for the SX814 which was not powered on (aka GingerGeeks main camera on the Epsrit 120) so I changed this to the Lodestar and took another image, this came into view! Not sure the problem of why it keeps reverting to the SX814 but I will need to check each time and will add to the TOSA User Guide.
Wrong guide camera selected 🙁
So I moved back to M76 entering with TSX again and took an image for guiding through PHD2 and full of stars, well a handful at any rate, plus a load of hot pixels (I need to apply some darks).
I see guide stars and hot pixels 🙂
The resulting guider graph was smooth, too smooth, and the resulting 5 min image was trailed! Ok so something else not right, so after taking a look it turned out I had selected a hot pixel to guide on, so I exposed a little longer from 5s to 10s and selected what looked more like a star and this time tried to guide. The guiding went off the chart which proved this was a star and that I needed to calibrate the guider (seemingly every night I go out, I will need to see if that is right). So off I went to calibrate the guider.
Guiding too flat…
Hot pixel not a star!
Finally a star but guiding off the chart!
In calibrating I realised the Darks were going to be needed, the first calibration run failed. I then went out to cover the scope using my trusty chair to help with the lift I needed to reach the end of the 12″ as it was point upwards. I then went back inside and took a set of darks ( I thought I had done this before), anyway with a new dark library in hand I recalibrated the guider.
Makeshift ladder…do not try this at home 🙂
Cover on scope for guider darks
Cover off scope
Now suffice to say the problems did not stop there, I had guider calibration failed, star did not move enough and after 4 attempts I managed to calibrate the guider and the guiding then started at last! the main thing was to change the number of steps required to 6 and the pulse time changed then to 1500ms from 200ms. This was enough to resolve the problem.
Guider RA and Dec are Questionable!!!
Guider calibration stars did not move enough
Guider calibration not enough points
Finally guider calibration successful 🙂
For completeness here are the settings I am now using that work in PHD2
Correct guider settings
So after much time spent and it now being precisely 22:33 I realigned M76 in the centre as it had moved with all the calibration challenges (remembering to change the filter to Luminance during the Closed Loop Slew in TSX and then back to OIII to start my imaging run.
I tested at 2 minutes first, then 5 minutes, then 20 minutes before starting the final run to decide on the subs I would use. By 23:14 I had the 20 minutes sub and settled on 20 minute subs for the rest of the night.
Guider graph looking very smooth
First 20min sub image down and fairly tight stars for my focal length and OIII
Quick stretch of M27 single sub in PixInsight
M27 zoomed section single 20min OIII Sub
Meanwhile the Summer Triangle of Deneb, Vega and Altair could be seen through the ASC and I noted that the star Tarazed in Aquila next to Altair at magnitude +2.7 could be seen also.
Summer Triangle through the ASC
I noticed the trellis lit up and had a quick word with my daughter to close the blind in the bathroom 🙁
Bathroom light on without blind down 🙁
Here is the temperature and pressure information from the dome internal sensors at around midnight.
Internal sensor readings around midnight
At 03:49 I decided to do a quick autofocus to see if the focus had changed during the night and given the temperature outside was now around 5℃. I paused the current sequence which gave me the option of cancelling or pausing at the end of the current image. I then ran autofocus but no stars were found. I went into the setting for autofocus within SGPro and changed the exposure time for the OIII filter from 1 to 20 seconds. This allowed the autofocus to see stars but the auto focus would not complete successfully and just kept creeping out. So instead I gave up, especially since astronomical darkness was finishing soon. Instead I slewed to my Flat position at Az 359, 21′ and Alt 00, 00′ to take the flats.
Co-ordinates for Flat Panel
I went out to the dome to manually turn on the light sheet which we need to automate and then turned it off after I took 10 flats through the OIII filter at 10 seconds each to get a good illumination. It would be 0.5 seconds through Luminance filter. I then packed up set the darks running and went to bed.
Configuring the guider to work with DirectGuide was tonights job, it was so important I have created a separate blog for it. That took the majority of this session before I really did need to go to bed for work tomorrow.
Once setup and now having the ability to reliably guide without the need for an ST-4 cable, I went to take a quick photo again to test the stability of the system. The importance of DirectGuide is worth labouring here as given we have 3 scopes to guide from, there is only 1 ST-4 port. We did not want to keep plugging in and unplugging the different cables, more did we want to build a bespoke connector for all 3, so DirectGuiding is really the only way this would work.
Once complete I once again tried to slew to the exact area for the Elephant Trunk, this has been problematic due to not quite getting sync and solve working, it works sometimes, and locating a star that I can reliably use. I have noted now that HD 205850 in Sky Safari and SAO 33570 in the SkyX represent the pair of stars in the main section of the trunk. I also took another frame nearby to label for future reference.
SAO 33570 centre of Elephant Trunk and SAO 33573 end of the TrunkNearby star pattern SAO 33626
Unfortunately Sync and solve failed and landed up moving the scope to the wrong area, hence I missed the object when trying a longer exposure with the Ha filter. I need to reliably get sync and solve working to be able to use SGPro else I will have to go back to The Sky X that I have used before for image capture which I would prefer not to do given the flexibility of SGPro.
So I landed up pointing at a star UCAC4 739:73701 which was an offset frame from where I needed to be, the purple oblong representing the FoV of where I should have been and the UCAC star showing where I landed up.
Pointing at the wrong object
SGPro did error as mentioned during Sync and Solve as can be seen in the screen grab below. I will talk with GingerGeek to resolve.
An unexpected clear spell this evening, I was sitting out on the patio looking at the clouds clearing and so setup the dome to perform the Periodic Error Correction (PEC) analysis for the mount.
To perform this I needed to unplug the hand controller for the MEII, unplug the ST4 guider cable, turn off a bunch of settings within the autoguider software with The SKY X (TSX) and also turn off TPoint.
I then connected the ZWO ASI1600MM to TSX rather than SGPro. This was so that I could record the log needed for the PEC through the autoguider add on software which records in a format that the PEC software requires. The challenge again was that I could not get the ZWO camera to connect in TSX. I just kept getting error 200. Searching TSX forum I finally found the issue and downloaded the latest driver from ZWO but through the link from Software Bisque. To install I needed to log in as Admin.
So I started to record the star movement without performing any guiding. Once done I imported the log file Autoguider.010.log into the PEC portion of TSX.
I then performed a fit so that you could see the sinusoidal waves before I then fitted the correction to it. A quick look using PHD2 Drift Alignment to see what the drift now was, was very promising with a sinusoidal wave over 10-15 minutes.
Final fitted curveModified CurveSinusoidal Drift Alignment check
I then went off and tried to image unguided to see if it made a difference, it had, I recorded a 10min unguided image through the 12″ 2.5m focal length scope with no trailing of Altair.
10min Unguided Altair exposure
I then attempted to slew and take an image of the Elephant Trunk in Ha again, however I was foiled by not only the cloud moving in but also not being able to get past the message Guider Settling. I need to talk through with GingerGeek to see why that is. Meanwhile bedtime for Mr Shave-Wall.
After several reboots by GingerGeek who is looking after the observatory I am now logged in. I currently have the dome open and the 12″ centred on Deneb that can be clearly see whilst the Sun is still above the horizon and thus not dark yet.
The rebooting is due to hanging of the NUC. We have had various problems, the external ASI120MC with ASICAP/SharpCap and Firecap seem to cause an issue, we have a problem rebooting and the NUC just powering off and today trying to login through Windows and it was just hung. So lots of niggles.
Tonight I hope to test a single Ha guided exposure on the Elephant Trunk nebula in Cepheus to the North East as it rises and will look to image from 11pm for a few frames before closing the dome for the night. I have already noticed that Deneb is drifting in my FoV so something is still amiss with the polar alignment event though I thought I had it cracked. I will make a note to go back and check it. Currently Deneb is +42 Alt and 66 deg in Azimuth. I think the key will be looking at where I pick the star for polar alignment and making sure I have truly tightened.
So now it is nearly 10pm the sky is getting darker. The strangest thing happened, the dome closed. I only noticed as the image was blank. I checked and the Hitec Weather Station had tripped and closed the Dome. I toggled the Relay and then I could open the dome. Interestingly if you try to open the dome from TheSkyX it tries then stops and resets to closed. For the moment given the clear skies and forecast I have disconnected the Hitec Weather Station software but will reconnect later. Something else to debug.
HiTech Weather Station Software
It’s now 22:21 and dark enough to focus, I spent some time getting the auto focus routine working in SGPro. Interestingly I had to set the step size to 1000 given the 100k steps my FLI focuser is capable of. I also increased the data points to 10 and this gave me enough movement and data to get a good V curve.
I managed to get down to an HFR of on average 6 tonight at focus point 71290. It took me 3 runs to get the right figures. I then made the changes under the 12″ profile within Profile Manager and saved them for future use.
Auto Focus Run
Next I moved on to PHD2 and guiding. Once I got an image I then found I only had hot pixels and no stars. I also had a funny cone of light and something large out of focus and the edge of the tube. I then remembered GingerGeek had fitted a new guard ring to the guider camera and inadvertently moved the position due to a loose screw elsewhere on the fitting. Thus I need to go and focus that the next night out as because I am not there tonight I cannot do this. This also means I am stuck for testing a guided exposure.
Very out of focus Autoguider
So instead I tried a few different exposures with the Ha filter unguided even though I knew I had the problem with polar alignment. I took exposures at 120 seconds and 180 seconds by which time I had trailing, given as I said I had polar aligned and could image for 10 minute exposures in a different part of the sky I need to redo the aspect. Note I did not perform a second autofocus on the Ha filter. I will at some point calibrate the offsets of the filters once I have the auto guider working.
120s Ha Elephant Trunk area still not dark
So at least a useful night to try and get a few things working, a few things to add to the ToDo list but all in all a good evening.
