So after ages I’m planning to perform some imaging after being challenged by Dave to produce a OSC image of M31 with the QHY268C that can be of print quality.
The first step was upgrading all the necessary software to make sure both the NUC and laptop would not be interrupted during my planned imaging session.
Windows10 latest Updates (Dec2022)
SGPro (4.2.0936)
NINA (2.1 HF1 Beta002)
ASTAP (2022.12.09)
ASCOM (6.6SP1)
Pegasus Ultimate PowerBox (1.6.1230.46)
iOptron commander (5.9.0.2)
The iOptron CEM60 mount hadn’t been updated in ages and it showed :
HandControllerV2 : 210106
MainBoard : 190716
RA board : 201005
DEC board : 190716
After performing the firmware update procedure, the mount was now showing the following levels :
HandControllerV2 : 220119
MainBoard : 211018
RA board : 211018
DEC board : 211018
Catalog : 150429
Of course I will need to perform a new zero mount position following the upgrade. Tonight I will also be changing the OpenPHD algorithm to PredictivePEC as described by Cuiv the LazyGeek :
Unusually it was a clear Friday evening. I did plan to be ready to go as soon at the pole star was visible but my imaging PC insisted on updates and the local hard disk was running at 10MB/s (replacement SSD on the way).
By the time I was ready, mount setup, polar aligned and balanced it was already late. I decided not to use the latest SGPro or NINA beta but just use the existing SGPro version. I was delayed starting as I was having issues with SGPro hanging when it couldn’t talk to the SQM (ASCOM Conditions Observing Hub) on a previous COM port, I need to report this back to the devs as a bug.
At this point Peg-Leg Dave joined me on a video call and we discussed imaging M45 in different modes on the QHY268C OSC. So we moved the scope to Alp Ari and proceeded to plate solve in SGPro, sync’d the scope Cartes Du Ciel and calibrated OpenPHD2.
Using the SGPro framing and mosaic wizard to decide on the framing for the target sequence I wanted as much of the reflection nebula as possible rather than being dead center.
M45 – SGPro Framing Wizard (FSQ85/QHY268C)
I’ve used the multi-star guiding in OpenPHD2 since it was first released in an earlier beta and I know Dave is looking forward to using it when he moves from using an OAG on his 12-inch RC to a 90mm guide scope to make it easier to get more guide stars or even one star.
Multi-Star Guiding in OpenPHD2
Whilst trying some mode/exposure tests the guiding started acting up in RA, so parking the mount and disengaging the clutches I redid the balance of the scope. It was only marginally off but it was enough to cause issues for the CEM60 …. it is not forgiving !
We decided to increase the Gain/Offset to 15/75 and use the Extended Full-Well mode (#2) of the QHY268C, testing the star brightness levels of various exposure times we opted for 180 seconds as that was under the maximum brightness level.
As I currently have no IP camera outside I like to see the mount position using GSPoint3D as I like to view where it is especially during meridian flips. NINA has this built-in now in the recent version 2.0 betas. As SGPro lacks this functionality I can use the view via this is standalone version that connects to the ASCOM mount.
Mount/Telescope virtual viewM45 – Pre Meridian Flip
SGPro paused the guiding just prior to the meridian flip. Following the automated flip, the guider and the imaging sequence automatically restarted after a plate solve and auto centering were performed.
Inverted shot of M45 (180s) – Post Meridian Flip
It gradually got cloudier just after midnight and the quality of the subs declined so I decided to stop acquiring data even though we really wanted over 4 hours of exposure.
I proceeded to take calibration frames. Using a target ADU of ~23,000 the SGPro flat wizard on the Pegasus FlatMaster (100%) gave an exposure time of 9.68s for the Optolong L-Pro filter, 25 flat-frames were taken followed by 25 dark-flat frames of the same exposure time and finally 25 dark frames of 180 seconds.
It was at this point that I realised that the FITs header showed a gain level of 0 and not 15, the offset was correct but I can’t be sure if the EFW mode was used as it’s not in the FITs headers. Only when using the native driver in NINA can you set the mode within the sequence, in SGPro the mode is set in the external ASCOM driver when the camera is not active in SGPro even though though it’s in the ASCOM API as the Camera.ReadoutModes property.
Also for some reason the default setting in the QHY driver is to NOT disable the overscan area which means I have black borders on my images which will make processing the data in Pixinsight a challenge !
I actually got to bed after 3am even though I had planned to stay up until the dawn. Next morning I noticed that my counter-weight had slipped and rotated on the bar. This may have also caused some of the issues with the guiding so I need to set-up earlier and check things more thoroughly in future to avoid these mistakes.
So although it’s not the data we planned it will be worth processing over a wine. The evening was a really a useful experiment and hopefully lessons will be learned …. if I remember the next time.
@ 19:00 Opened dome in order to cool the dome and scope down.
@ 21:00 GingerGeek arrives, wine is poured and we took 5 x darks, flats and bias for both the last run and tonight. The flats (red) were 3 seconds exposure to get 2/3 well depth required for this.
@ 21:44 Slewed to WASP-93b before we set about focusing on a nearby magnitude 5 star using the Red filter. Starting focus position was 58841@19.42℃.
@ 22:06 After failing to focus using the Red filter we resorted to using the Luminance filter to auto focus and achieved a excellent fit (focus position 61630, HFR 4.95 @20.83℃).
When we swapped back to the Red filter, SGPro then moved the filter offset to focuser position 60630. We slewed back to WASP-93b (GSC:3261:1703) and found a guide star just off centre of the star field with the exoplanet target.
Started to take exposures to find the brightest value of the centre pixel of the star and make sure it was 2/3 full well depth and thus 33,000 ADU (even though it is a 12-bit camera SGPro is set to 16-bit for ease of use. Eventually this was achieved at around 200 second exposure.
@ 22:51 Started imaging, 18.21℃ was measured at the focuser.
Frame and focus of starfieldTarget star for Exoplanet measurements Local conditions200s exposure of starfield
Started around 21:15, Guiding by 22:02, Capture started 22:22, Finished at 03:31.
Dave and I are part of the amateur exoplanet monitoring effort for the ESA Ariel mission. We decided that we would allocate some time to try and provide observing data towards the project whenever we could.
Part of this requires some forward planning such as looking at the upcoming transit visible and their associated time. This is due to the altitude of the object, the ingress and the egress times of the projected transit.
Prior to this we had discussed in advance which object to target for the chosen evening. All the hard work of choosing objects is done by the Exospies project website as they list the candidates they need data for via a schedule. So it’s a simple task for use to go through the list and work out what fits best for us.
Unfortunately whilst opening the dome to cool down I decided to review the schedule but I was hit with a server 500 error from the website. In a panic that I might miss the start of the event I scoured the internet for alternate exoplanet transit time websites and found the excellent Exoplanet Transit Database of the Czech Astronomical Society.
I had issues with focus drift all night due to the temperature fluctuations but at a recent Zoom session it was discussed that images can be out of focus with no detrimental effect on the measurements :
SGPro Image History
I was unable to auto focus successfully maybe due to the low altitude and seeing. I also discovered that temperature compensation was enabled so we probably need to remeasure the temperature compensation coefficients so the focus deltas are better between the par focal filters.
The object was at a relative low altitude, the outside temperature was warm and although the skies appeared clear our AAG CloudWatcher sensors via the Grafana dashboard told a different story. For us a truly clear sky is anything equal or lower than -18℃.
Sky Temperature – it was clear but it wasn’t !
Sky Temperature – T’was warm !
After performing a meridian flip, resumed the guiding I started to feel tired so I set my alarm for 3am and went to bed. Unfortunately there appeared to be a guiding issue at some point shortly I went to bed.
Guiding issues shortly after meridian flip
This was investigated using the phdLogViewer and shown to be a loss of guide star and didn’t recover for around 18 minutes.
The guiding issue also caused the image to shift so the target and reference stars moved. We need this in frame in order to run the frames through the provided HOPs data analysis program which hopefully won’t have a problem in reading them. That’s an exercise for this weekend and hopefully we will have enough data to yield a decent light curve that we can submit.
GingerGeek and I were out imaging tonight. The sky unexpectedly cleared and we thought given the impending move of IMT3 to another site that we would try to gather some more data on M57, specifically LRGB and some additional Ha on the 12″.
We ran Autofocus on Luminance which gave 60,671 at 20.64℃ and HFR 6.5. We then started to image and after a few frames the temperature started to drop. In the main this is because we opened the dome last minute rather than a minimum of 2 hours before we used it so the dome was warm and now cooling down the optical train shifts.
M57 quick frame and focus
We refocused to 62,712 on luminance at 19.10 with an of HFR 5.15. We then ran the image acquisition and below is a screenshot of the guiding, which looked like it was going to cause an issue but it was ok. If it had then it would have been the local fog rather than anything on the mount. At midnight we performed a Meridian flip nice and early which afforded us to leave the observatory running and go to bed. Notice the graph below, the yellow line drops as we performed the meridian flip, this is due to the dome now shielding against next doors light !!!!!!!
Guiding ok, notice the drop in the graph
The neighbours light continue to be a pain as can be seen here, I really cannot wait to move the observatory to it’s new dark site.
LIGHT!!!!!
Finally managed to capture LRGB and Ha, below the RGB and Ha frames can be seen in PI. Note the central star is not visible in the Ha frame,
RGB and Ha raw frames
Finally I stacked 1 of each colour without calibration to see what it would look like.
RGB quick single stack no calibration
So we left the observatory imaging, I had a quick peek outside around 12:30am and there was water running off the dome and the outside windows of the orangery! The Observatory ran until the dome shut at 3:58am (it woke me up) when the light levels started to rise.
So I opened the dome late this evening as it was not due to be clear. However an opening in the cloud meant I could test guiding again on the 12″, especially whilst it was light in the late Spring weeks.
The first job was as always to focus which brought me to a reading of 61944 at 19.83℃.
Focus run
Another small job was to sort the guider FoV out. I went ahead and used M92 to align the guider.
Aligning guider FoV using M92
The final FoV settings are here for completness.
FoV for guider
Set AS1600 to Gain and Offset 10 due to cluster being very bright and I needed to set a standard of 60 seconds minimum exposure. Gain 139 and Offset 21 gas saturated unless I selected 15 seconds, Gain 75 and Offset 12 saturated at 30 seconds so hence 10 and 10 which came in about 58k ADU.
I then performed a slew to a nearby star so I could centre the scope, there platsolve completed successfully and I updated TSX and the FoV for the 12″ with the new angle.
Platesolve
The first image of 60 seconds came down and was out of focus, I then realised changing the profile SGPro forgot the autofocus setting, so I had to stop the run, delete the images and set the original focus point then rerun.
M92 out of focusM92 in focus
Next I ran a few images but then to my horror I had the same guiding issue, where the star moves being dragged up and down in a periodic way. I slewed elsewhere and tried again and the problem did not occur. I was near M92 and just East of the Meridian and quite high up. Not sure why that is a problem.
Near the Meridian
I could not resolve, I waited a while then performed a meridian flip and low and behold the problem went away, again not sure why. I still have this terrible noise coming from the RA motor/gear area. I decided to bite the bullet and take off various caps on the scope listening and looking inside. I decided it was not after all, the through the mount cabling but coming from the RA gear itself, so I looked for the MEII guide for removing the worm block and then followed the instructions to take off the RA cover.
RA gearing and belt noise
This gave me instant feedback on what the issue was, the belts driving the axis were making a noise. On looking through forums on Bisque.com I found a few people with similar issues and needing to grease the belts, they were told Lubriplate was a good grease. This is an American grease so I will find a similar here and then apply, I will ask Bob first for his suggestion.
So the night wore on and the LRGB frames of M92 I thought I would take whilst testing guiding progressed. At one point the imaging stopped due to cloud. I just caught the dome before it closed to change the safety sensor due to cloud. When it cleared it never really cleared, with the sky temperature reading about -14℃.
Not very clear
Nearing the end of the imaging session, I had caught about 15 frames of each of the filters.
Good guiding and imaging
The guider was behaving mostly with he odd funny jolt. By 3:30 am the sky was lightening very quickly.
3:30am and bright
By this time I had stopped guiding and imaging. I closed the dome, slewed the scope to the flat panel and proceeded to take a set of LRGB flats for Gain 10 Offset 0 and also Gain 139 and Offset 21 as request from the previous nights imaging.
Now guiding on star to West side of mount around 0 degrees Dec and near the Meridian to see if problem reoccurs, graph looks ok but there is a slight regular pattern of error.
Slewed to M92 which is a glob currently at Alt +74, Dec 43 and on the East side of the mount where I had issues last night. I plate solved the image.
The auto focus run looked good
Found guide star by moving M92 slightly off centre. Now guiding. All looked good for a short while. So each section of PHD2 graph is 25 points, so when you have 100 points selected there are 4 sections of the graph. This mean each section/column represents own my case 250 seconds as I expose for 10 seconds, so just over 4 minutes per section. So the errors I saw last night were about 12mins apart. This cannot be the work gear as it has a cycle of 2min 29sec. This is from the latest Paramount manual for the MEII.
Tracking at the sidereal rate, one revolution of the worm takes 149.6 seconds (2 minutes 29 seconds).
The right ascension gear has 576 teeth.
The declination gear has 475 teeth.
The error I am seeing is about 4mins. I cannot continue imaging as every few frames are trailed.
The first thing to do were Flats for Ha first for the previous night but also for use tonight. I completed this at 22:15
At 22:31 I performed focus run on Luminance which came in at position 59841 with HFR 4.77.
I started an image run as soon as the Pelican Nebula (IC5067) was above the neighbours house. I have set a run of 10 x 600s and 20 x 300s Ha subs guided with the new PHD2 settings to prove the 12″ now works from 1 night to another. Then we can try the Esprit on the next clear night. The guiding at first looked okay.
Good initial guiding
The resulting image looked very good too
300s Ha guided Pelican300s Ha guided zoomed no trailing600s Ha Pelican guided600s guided zoomed no trailing
After about 5 frames I suddenly ran into a problem the guiding looked like this
There were large movements in the Dec and the RA would not return to centre. Soon enough SGPro stopped imaging and tried to settle the guider and then further complained about not being able to settle. So I temporarily changed the Hysterisis from 10 to 15 to see if this would get the star back. It did, well just.
The RA axis returns to the centre after quite some time. Is this possibly seeing related or is there something mechanical amiss with the setup?
I did notice the problem one more and then went off to bed left it running 01:09 leaving the possible bump in the worm to resolve itself.
bump in the worm?
Addendum – So got up this morning and the scope had continued its travel across the heavens. I looked at SGPro and it finished the sequence without any problem. I then looked at PHD2 and expanded the time to include the maximum span possible as it had been trying to guide after loosing the star (I have check boxed Enable Star Mass Detection in the hope this fixes it) and I noticed a problem, which is the recurring South then North oscillation which I now need to investigate as that is the cause of loosing an image due to the star moving. It looks for all the world to be on the worm gear. I will set about measuring the PEC tonight and see if I can see it. It may of course be from when I adjusted the work due to another problem I had and it may not be quite right. I will also ask on the forum.
Esprit 120 FHR was 1.99 for Lum and 2.54 on the Ha
Focused on Deneb , 30 seconds exposure produced HFR 2.23
Deneb – 30 seconds in Ha
Solve and Sync
Solve and sync completed on Deneb in Ha
The focus point for Ha was 6217
Now for a quick frame and focus, 30 seconds exposure
30 seconds Ha on Pelican as Frame and Focus test
That looked good, next up was to see if we can image for 5 minutes unguided and see what the resulting image looked like
300s Ha Pelican
Again the resulting image looked very good and no star trails
Clear skies with -18℃ measured by the Infrared sensor on the AAG Cloud-Watcher.
AAG Infrared sensor read -18c so zero clouds
I then tried a 10min image but got clear trailing.
Star trailing at 10 minute exposure
So I set the guiding up with PHD2, went out to the dome and created a dark library as this was not done. I then set about training the guider and then set it running, initially with a 4 second exposure. The resulting guide graph looked a bit bumpy. The ASC looked very clear this evening which was the first time in a while. You could see stars to the left hand edge of the image which is normally obscured by cloud.
ASC Clear skies
We decided to run the guiding assistant in PHD2 and see if there were any changes that needed to be made. It came up with some suggestions including redoing the calibration and changing the calibration step size from 1600 to allow more steps in the calibration, in this case I changed to 1200 to try and go from 3 steps per axis to 8, however I got to 6 steps and this seemed good enough. When I then reran the guiding assistant I no long got the error about calibration. I did have a few suggestions as seen below which I applied.
Guiding Assistant recommendations
So the changes made still have not allowed 10mins images, they are still trailed. So that I do not waste any further time this evening I captured 5 minute images instead of 10 minutes and I will relook at the guiding next week when the Moon get brigheter.
At 1:38 we gave up on guiding and switched to 12″, Autofocus on Lum, 63384 HFR 5.4. Took some 5 minute and a single 10 minute frame guided, scope trailing ?
There were three scopes on the Pelican Nebula (IC5070/IC5067) tonight as GingerGeek was imaging with the Tak FSQ85 from his back garden.
3 Different image scales from tonight
Finished to go to bed at 2:56 am, GingerGeek finished the session by taking flats, warming up the CCD and bringing the scope indoors just after 3am.
Rough stack of Ha (5nm) 10×600 seconds, -15℃ From the FSQ85
Opened dome at 4pm to start cooling the 12″, but actually started to play by looking at guider on the 12″ at 9pm. The guider had never really produced round stars and I suspected this was due to it not being pushed all the way in, far enough to be in the sweet spot for focus.
So I took off and adjusted with a spacer of which I had many in different thicknesses. I found the ideal one to fit that would allow the filter wheel Now round stars. Given high cloud I have set running on M5 LRGB, 60 x 60 seconds L / 30 x 60s RGB. Not guiding. Gain 139 Offset 21. Cooler -15. to rotate far enough that it did not fowl the guide camera, which until now it had. Now this was done, it was time to test.
Round guider stars
The images were much better, the stars tight and round. I also changed the rotation of the guider so that its chip was square to the rectangular whole in the light pickoff shaft.
Stretched M5
So now that was achieved I went off to image M5, but without the guider as I could not find a guide star……..typical. I chose M5 as we have some frames from a previous night in May but focus was not as good as tonight and the ADU was too high. I left the scope running 60 x Luminance and 30 x RGB and went to bed.
Images captured for M5
Addendum. The dome shut when the Sun started to rise which is fantastic and working as designed. What is not is the AAG must have hung and although I could see in Windows Task Manager it was nowhere to be seen, not in the icon tray or open as a window. Also I forgot to keep the dome log open in TSX so could not see the time stamp of closure. I will have a check list for the next night out. Also I now realise the pick off mirror obscuring the corner of the camera chip for the main camera so I need to either move where the light is picked off from or move the mirror out slightly without effecting the focus.
OAG Pick off mirror obscuring main camera in corner
I have also now started to process the image and on close inspection to the frames I can see the cloud moving across in the Red channel. Here is the results for the processed image.
Just setting up for an imaging run and to test imaging without temp compensation to see if the 12″ keeps focus without it. I started by myself then was joining by GingerGeek and then Bob.
Performed a SGPro autofocus run on Mag 7 star produced focus position of 71,828 @ 4.6 HFR at 14.47℃.
1st autofocus runResulting M98 image from 1st autofocus run
The resulting image was good with good star shapes. Although I suspected at this point the seeing was not excellent.
I let the sequence run for a bit imaging M98 through LRGB and then decided the HFR was gradually getting larger so I performed a 2nd Autofocus run which came in at position 72,215 HFR 5.7 at 13.97℃.
Again I let the sequence continue for at least 4 images and the performed another Autofocus run, note all the time this was on M98 and not slewing away to another star. This came in at focus position 72,697 @HFR 5.7 at 13.82℃.
I continued this routine again and performed another Autofocus run on M98 focus position 73,441 HFR 5.4 at 12.98℃.
I then decided, due to struggling to get a good HFR on focus runs to see if the autofocus was introducing an issue so I changed the autofocus setting from 9 data points to 11 data points to try and get fuller deeper curve. The resulting curve was better and more complete on both sides of the U shape. I then imaged further and then attempted an autofocus with the settings change for the step size from 2500 to 1500 and data points from 11 to 15. This was because I felt we always have a flatfish bottom to the autofocus which at this focal length of 2.5m shows the quality of the seeing with a narrower flat bottom being better seeing. The new autofocus came in at position 73,534 HFR 5.1 at 12.66℃. Meanwhile we kept noticing satellites going across the ASC which I now believe are potentially StarLink so very annoying.
ASC with Satellite
The new autofocus settings seem to work better. Anything less than 1500 step size would be less than the seeing, as proved tonight so I may find that 2000 is ideal, a test for another night. Also noted that Red filter was showing the worst HFR changes due to seeing and humidity was around 75%, again worthy of note to see how good the seeing is. The guiding was all over the place tonight, again another indicator of poor seeing. So all these things are not poor setup or poor software but poor seeing!
This I believe was the ISS going over captured in the ASC.
ASC and ISS
I was really pleased GingerGeek and I had spent time a week or so ago when the Moon was around working out the location of the Field of View (FoV) indicator on TSX, it makes it much easier to find a guide star, although tonight M98 had a couple strategically placed which was great.
FoV for Off Axis Guider and the OS main camera
By 2pm the cloud had started to appear, first at South Winston with Steve’s setup, then at Mil Dave’s at Tadley and finally here some 15 minutes later. The guide star was lost by PHD and SGPro in a well ordered fashion did what it is really good at and stopped imaging.
SGPro can’t continue imaging due to guide star loss 🙂PHD2 and guide star loss due to cloud
Here is where I got up to so LRGB on M98 for the night with 15 x Luminance and 12 x Red, Green and Blue was the original first image for each was there wrong exposure time, so RGB at 2mins and Luminance at 5mins. Very happy for an evening testing and gathering data at the same time.
Here is a set of image statistics charts for each filter for the HFR changing over the evening whilst I refocused. Next time I will focus once and not refocus and see what happens with the temperature drop.
Final look at the AAG weather station as the cloud sensor which is Infrared makes the dome unsafe and shuts it.
AAG Weather Station now Cloudy
Here is the final view from the ASC
ASC and cloud
and of course to finish the evening off another satellite!
Imaging M99 and Bob did M12 later. Some of the luminance for M12 will need to be thrown as it was too bright, however the RGB data is good. We managed to bag 24 x 5 minutes luminance for M99 and a set of 12 x 2 minutes RGB.
M99 Quick frame and FocusM12 5 minutes Luminance
This is a stacked version of the Luminance data.
M12 Luminance stack
This is the final imaged that I then processed for M12 on 5th December 2021! This was a combination of 62 x 1min Luminance and 7 x 1min for RGB channels. I need to bring out more of the data from the luminance in retrospect.
22:05 Frame and focus on 9.26 and 7.64 magnitude stars used before moving to M61 to capture some Lum frames for calibration of flats to solve the doughnut embossing.
22:18 Slewed to M61, performed Solve ‘n’ sync, slew here for centring the object, ran four Luminance subs of 300 seconds each (Bin1x1) at Gain 139 and Offset 21. This was completed by 22:38.
22:45 Chief TOSA then warmed up the CMOS camera, set the filter wheel to the empty slot position, powered off and disconnected the camera and filter wheel. This was so the ASI1600MM and filter wheel could be detached and a blanking filter installed into the empty filter wheel slot position without having to open up the filter wheel. The idea is that we move to the blank filter position when taking Dark subs to prevent light leakage on the Officina Stellare 12-inch.
22:55 Everything was back online and the SGPro profiles were modified to reflect the new blank filter location.
23:13 Unfortunately a dust mote was introduced onto the CMOS sensor window so we sent Chief TOSA back out to the dome to do the job properly this time 🙂 This meant parking the mount, warming up the camera, powering off the camera, remove it, clean the sensor and reattach the camera.
23:24 All reassembled and powered back on, slewed to NGC 4147 (Globular cluster) ready for a a 60 second Lum filter test which showed that a decent cleaning job had been done ….. about time too !
23:40 As it was getting hazy/cloudy it was decided to collect some calibration frames, in this case 25×10 minute dark subs at Gain 39 Offset 21 using the new blank filter.
23:50 We logged off from the remote session and left the dark frame sequence running until it was due to finish in the early morning.
Bob, GingerGeek and I rationalised the SGPro Profiles and created a smaller set to account for the fact we could now dynamically change the guider in SGPro and also simplify the Gain, Offset and the sensor set temperature within the profiles.
Before we did this GingerGeek recorded the Brightness value from the AAG weather station and the SQM reading as nautical twilight occurred
AAG and SQM readings at Nautical Twilight
We agreed on the following basic parameters for imaging. 3 profiles for the OS OTA at 3 different Gains and Offsets. 1 profile for the Tak with the need to change the parameters of the camera to one of the 3 correct Gain and Offsets now documented in the TOSA manual. Finally 1 profile for the Tak and as it is a CCD then there is no Gain or Offset. We also agreed the premise of exposure times for the 3 OTAs to make calibration frames simpler – 1, 2 minute for RGB on the OS, 5 minutes for Luminance and 10 minutes for narrowband. For the Tak as it is a OSC we agreed on 1, 2 and 5 minutes. For the Sky-Watcher Esprit 1, 2 and 5 minutes for Luminance and 10 minutes for narrowband. We also agreed on the temperature of the scopes to be run at as suggested by Dave Boddington, we have gone for semi-simple. So for the OS and Esprit we will image at -15℃ in Summer and -25℃ in Winter. For the Tak we will image at -20℃ all year round. Note the new Flats are at the new lower 23k ADU setting.
New set of simplified profiles
So now all the profiles were changed and setup, we set a sequence running for OS Gain 139 Offset 21 for Flat Darks and Darks 1, 2 and 5 minutes. We will need to do 10 minutes tomorrow night. The Flats incidentally for this set of calibration frames was then completed the following morning by 11am before the Sun got too high and the camera failed to cool to -15℃.
Flat Darks for new profileDarks for new profileFlats for new profile
Finally I saved the sequence as calibration frames for OS Gain 139 Offset 21 so that it is now easy to pull this up and redo if needed. I also took Bob’s advice and separated out the Flat Darks, Darks and Flats into different tasks. So tomorrow nights job is narrowband darks using this gain and offset followed by starting the new run for gain 75 and offset 12.
Opened dome early switching the safety for the brightness on the new AAG. The first thing to do tonight was to calibrate a little but more the infrared sensor which informs the cloud coverage. This was suggesting it was Cloudy, borderline Overcast and given it was very clear with a hint at wisps of cloud I adjusted the couple of figures for the sensor, from -17 for Clear to -14 and from -14 for Cloudy to -12.
I then set about taping up the USB and power for the SX camera on the Esprit. This is because the connectors supplied are clearly not in tolerance as I have tried many cables and they call fall out. The tape should suffice for the moment and now the camera reconnects to the NUC computer running SGPro.
Tape for USB cable
GingerGeek and I started to have a look at the sky around 9pm. The sky was not totally clear with some wisps of cloud. We tried to get to a point where we could test guiding the 12″ through the Esprit, however as ever the clouds rolled in. However, during setting up the SX814 camera on the Esprit as the guider and performing a darks calibration run we got an error on the USB bus again (we get lots of USB errors) which not only kicked out the SX814 but also the AAG weather station. The problem was it almost killed the AAG software and we had to cancel the process running to resolve. This meant we lost all the settings in the AAG so we have tried to rebuild as per the new screen shots below.
AAG Weather Station New Settings
So instead we re-ran the Flats Calibration Wizard for the OS with the camera set to Gain 139 Offset 21 and also another run at Gain 75 Offset 12. The reason for re-running is that I suspect the flats we have are ever so slightly over exposed at 30-32k rather I prefer them to be at 22-23k.
We also created 2 new profiles that were simply named so we can see them in the list and simplify the naming convention and amount of profiles needed. We will choose the guider on the night within one of the two profiles created. We will also look to review and simply the other profiles for the two additional OTAs tomorrow and delete the remains profiles given the large number we now have.
Camera -23°C, focus point 74534, temperature 15.81℃
Frame & Focus / Plate Solved / Centred
21:38 Autofocus Run – Failed.
21:50 Integrating M85 Event 1 Frame 1 for 300 seconds Lost guide Star
22:13 Switch Guider to SW Lodestar
Integrating M85 Event 1 frame 1 for 300 seconds. Aborted run as M85 approaching the meridian and guiding graph was not looking good. Guider not calibrated.
Meridian flip to Chertan in Leo, Tak FS-102 now on top of configuration, Esprit below the OS 12″ so will be the better to guide with the QHY5 MiniGuideScope attached to the FS-102.
22:51 Slewed to a star field near Chertan for Auto Focus run. Start focuser position 72885, final focuser position 72178 ….. nice graph.
22:56 Calibrated QHY5 MiniGuideScope guider
23:08 Calibration suceeded, guiding.
Stoped guider and slewed to M85 which had just crossed the meridian.
Frame & Focus / Plate Solved / Centred
23:21 Integrating M85 Event 1 Frame 1
23:44 Telescope connection lost due to poor communication
23:48 SGPro reported USB error – lost FLI Focuser. FLI connects Ok in The Sky X.
Fix is to click on the spanner in SGPro for the Focuser and Rescan, Focuser now reconnects.
The plan was to capture data of NGC 4565 with the OS RiDK 305mm after the testing I’d done the previous night attempting to determine how long we could go with unguided exposures. As NGC4565 was due to transit at 23:36 I thought I’d wait until I could slew to it without performing a meridian flip so went chasing Comet C/2019 Y4 ATLAS to see what remains of it. However, judging by the horizon it was about to disappear from view but I grabbed a few frames anyway. Unlike previous attempts where it was clearly visible in a 60 seconds exposure I was now exposing for 180 seconds to make out the fuzzy remains.
23:15 Slewing to NGC 4565 would still require a meridian flip so I went to NGC 2903 which I’d looked at recently. set a sequence going to get 30mins of data with 5 minute subs. Auto focus succeeded at the start of the run.
00:05 Slewed to NGC 4565.
Solve and Sync then slewed the framing to try and include NGC 4562 in the FoV.
Started sequence to gather 12x 300 seconds Lum, 6x 300 seconds R, G, B and 6x 600 seconds Ha subs.
SGPro failed to start the Guider and aborted.
PHD2 started manually and 5 frames of Luminance gathered before the guide star was lost and the sequence aborted. Profile does not have ‘Recovery’ set. Need to discuss this with DSW and GingerGeek. While looking at the option found in Tools > Options > Sequence I also noticed that ‘Pause Guiding during autofocus’ is not set.
Mil Dave showed me a procedure he believes is documented in the manual to centre the telescope on a previous image, but this failed to move the mount as expected. I later realized it may have been because we did a ‘Solve and Sync’ followed by a ‘Centre Here’ ( which hasn’t worked for me before). I need to see if I had done a ‘Solve and Sync’ followed by a ‘Slew Here’ whether that would have had the desired effect. Using ‘Slew here’ I was able to reasonably match the coordinates of the original frames (after unsuccessfully trying to ‘Slew to coordinates’ in the Sky).
Update 23Apr20:
Having discussed the above with Dave, I believe we identified where I was going wrong but also discovered some points along the way.
We noticed that the RA and Dec I had recorded from the SGPro Plate solve of the image did not match the numbers recorded in the FITS header of the image and using the SkyX to Slew to the coordinates recorded was off because I hadn’t selected Epoch J2000.0 (used by SGPro) but had used the default Sky ‘Apparent (i.e. current)’ setting for the Equinox.
Additionally, after performing a ‘solve and Sync’ in SGPro, I should have gone to The SkyX and syncronized the Telescope.
Turned off the guided and finally resume a sequence
03:00 Of to bed for me, leaving the sequence to run for a further 1hr30.
Tonight GingerGeek, Bob and I wanted to make sure the newly installed version update for SGPro was working. In particular we wanted to get the sync and solve working, so that we could centre an object, but also the autofocus as the was a major update.
In TSX select an object and slew to itIn SGPro take a quick 5s image of the objectIn SGPro click the Solve and Sync button on the bottom leftIn SGPro the image is now solved and synced to in SGPro
In SGPro right mouse click on the object and select Center Here from the menu
In SGPro select Yes on the Center Telescope windowIn SGPro take another 5s image using Frame and FocusIn SGPro the object should now be in the centreIn TSX from the Telescope tab click on the Start Up button and select Star SynchronisationIn TSX make sure Synchronize mount into existing model is selected and click on SyncIn TSX notice the FoV indicator from the camera has shifted to a new positionIn SGPro take another 5s image using Frame and FocusIn SGPro the resulting image should not have moved
The mount in TSX and SGPro are now synced to the correct position in the sky.
M94 and NGC 3395/3396 are the 2 targets for tonight, some luminance on M94 and RGB on NGC 3395/3396 if I get enough time. I always try to open the dome early to give at least 2-4 hours cooling before I use.
View from the bridge
When I was about to start with autofocus I tried to recenter back on the target but the mount respond and it transpired that the mount thought it was out of balance. I went to the dome and the mount was beeping proving it was out of balance. So I turned the mount off, manually moved the scopes pack to the park position and then turned the mount back on and all was well.
@19:57 I performed the autofocus for the night on Luminance which scammer in at a position of 75282 on the focuser.
1st AutoFocus run
@20:10 I started an imaging run of 24 x NGC 3395/3396 with Luminance filter. Once done I planned on grabbing RGB frames before moving on to M94.
NGC 3395/3396 Luminance
@22:32 I started on the RGB frames for NGC 3395/3396 after refocusing on the Red filter.
Single Blue frame for NGC 3395/3396
@1:40 I slewed to M94 and changed the filter to Luminance. I performed a refocus and shifted from 77895 to 75884 on Red filter by accident. So we (I had Bob on Zoom by this point) refocused on the Luminance and the new focus position was 74884. So the difference is 1000 for Luminance to Red. I also changed the step size for the focuser temperature compensation from 531 to 431 to see if the HFR is more stable.
A new autofocus on Luminance
I noticed tonight that PHD2 lost the Use Direct Guide check mark twice and thus complained about pulse guide not being supported. I had to stop guiding, disconnect the mount in PHD2 and go into the settings, check the Use Direct Guide and reconnect the mount and start guiding again. Something to look into possibly.
Quick frame and focus 20s of M94 Luminance
@02:07 I went to bed and left the scope gathering another 2 hours of Luminance data on M94.
Addendum …….
The following day I took the ZWO ASI1600MM CMOS Camera off the back of the 12″ and cleaned the sensor window. What I found was the dark dust doughnuts disappeared and the rest for the doughnuts were actually on the filters.
Before cleaning Flat from Luminance on ASI1600MMFlat from Red after cleaning sensor windowFlat from Green after cleaning sensor windowFlat from Blue after cleaning sensor window
Things to still resolve……..
Check out why WSX is loosing connection and shutting the dome
Fix Slew Here and Centre Here in SGPro that does not work
As I found last night I need to get Temperature Compensation working for the focuser if I am to produce any decent images. SGPro has a Temperature Compensation Trainer which I will follow.
Temperature Compensation Trainer in SGPro under Tools menu
I started @19:35 by taking an image of a star field to make sure there were no bright stars and then ran the autofocus routine. This came back with a focus position of 76974 at 11.5℃.
First autofocus run complete
Next I started the Temperature Compensation wizard which seems to measure the difference in focus position over a 5℃ decrease in temperature. It takes the initial reading above and then you wait until the temperature has dropped by 5℃.
Temperature Compensation Trainer Starting figures
It took 3.5 hours for the temperature to drop by 5℃. So @23:08 I then ran the autofocus routine and got the next image and result. This resulted in 531 steps per 1℃ of temperature change.
