22:00 – 23:59
This evening GingerGeek and I simply set out to align the off axis guider of the OS on TSX. We did this buy focusing on the Moon and adjusting the off axis guider for he crater we were seeing. The resulting image is not very good which give rise to a though that the OAG should move it’s position in the imaging train to give better star renditions, the issue is I think it is as far back as it can go due to the filter wheel.
22:20 – 01:32
I have placed new filter, Baader IR-Pass 685nm from Mark Radice on the ZWO tonight and aimed to go after Venus on the Mak180 and capture another phase of the planet. I recorded several sets of data although noticed the filter does produce a somewhat pinky image.
21:23 – 01:29
NGC2903, focus point 73,602 for Lum HFR 5.46 Temp 18.13
NGC4565 @ 00:59
did not work straight away due to centring issues after reading in old image to plate solve and use as basis for slewing scope with SGPro. Finally just did this with TSX and worked.
@01:29 started Lum sequence for NGC4565 at -23℃ and 300 seconds
22:20 – 01:32
Imaging M85 LRGB through the OS12 at 300 seconds, Gain 139 Offset 12, temperature -23℃
Went off to bed and left Bob with scope imaging until morning light.
Viewing time period – 22:05 – 03:36
Update on viewing with Bob running IMT3 for the night.
So after joining the BAS Zoom session I asked what others were imaging and got a spiral galaxy NGC4535 from Trevor and the Needle NGC4565 from Mil Dave.
I slewed to NGC4535 which included a meridian flip and found it pretty much in the centre of the fov. Started a sequence of 3, 5, 10, 12, 15, 20 minute subs but aborted after the 15min subs as trailing was evident. Focus could also have been improved.
NGC4535 and NGC4565 were approaching the meridian so I did a flip to Praecipua in Leo Minor and then a slew to some nearby fainter stars to do a focus run. Start Focus position was 75542 at a temp of 14.14. After focus run the new focus position was 73335 HFR 4.7 98%.
Now slewed to NGC4565 and set a sequence of 12.5m (750s), 13.5m (810s), 14.5m (870s) subs going trying to establish where the limit is for unguided in these conditions. The first 750s sub was fine but the 810s was just showing a little elongation. I aborted the 870s sub and started a run of 12.5m (750s) subs going to see how consistent the results are … will need to look at these in the morning but I think this is about the limit and would probably back off to just 10m subs to provide a bit of a buffer.
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
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 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 time period – 21:19 – 23:23
Slewed Tak to M53 started to take colour frames. Clouded up around 11pm so shut dome and took darks, flats and flat darks.
Viewing time period – 18:16 – 23:15
Here is my workflow so I can repeat each night until this is finished.
Open dome – done
cool down – done
turn off dehumidifier – done
turn off fans on scope – done
find home – done
focus – done 60,535 clear
remove existing model – done
slew and sync to nearby star – done
make sure scale is correct -done
make sure image link to all sky database is selected – done
start TPoint run – done @ 21:13
Complete TPoint – 93 points done, paused TPointing at 23:15
Turn on Dehumidifer – done
Note that tonight I found the dome was definitely not lining up with the 12″ OTA. We have noticed this gradually becoming as problem over the past weeks and months. I am not sure if this is a problem with software, hardware, a change in settings or the temperature of the dome in some way has effected this. To this end I will set about a calibration run of the dome tomorrow to see if that can rectify the issue.
Viewing time period – 20:59 – 23:42
Here is my workflow so I can repeat each night until this is finished.
Open dome – done
cool down – done
turn off dehumidifier – done
turn off fans on scope – done
find home – not needed
focus – done 59,659 clear – done
slew and sync to nearby star – done at 21:06 as not dark enough before then
make sure scale is correct -done
make sure image link to all sky database is selected – done
start TPoint run at point 93 – done @ 21:10
Complete TPoint – 231 points done at 23:46 including checking 5min unguided exposure which was fine
Turn on Dehumidifer – done
So what did I learn tonight? It was worth doing the TPoint model. The resulting pointing accuracy is much better with objects being almost centre off the chip. Unguided images on the 12″ look good at 5mins, I will try longer when the clouds and rain disappear. That following a documented approach helps as above. The adjustments to the worm and the loose weight helped. That fixing the dome rotation slippage on the encoder today helped.
I mentioned above the dome slipping on the encoder, this was because of the small weak spring that is used on the dome, which is not good enough and over the past year has stretched beyond its limit. This means as the dome rotates and the dome shudders due to the joins in the dome not being flush (another issue) and thus the spring is stretched. This meant that some of the time the encoder wheel seen below was not touching the dome and therefore lost around 30-40 degrees. To rectify I have temporarily stretched and tightened the spring which we will replace later with a more suitable one.
Viewing time period – 20:30 – 22:30
Tried again to get the TPoint completed tonight but hit with a load of issues which I will try to sort tomorrow. FoV in TSX was wrong. Not plate solving in TSX. Focus potentially an issue. Use of All Sky Image Link for Scripted Image Link needed to be selected from the Image Link –> All Sky tab. Image scale in various places was incorrect again and should be 0.32. Managed to get to 10 points with 3 failed. Clearly something has changed given this worked a week ago. I will attempt a go tomorrow night to resolve. Meanwhile I have left Bob to image. In hindsight we should also be leaving the observatory running all night as when I got up at 4am it was crystal clear and dome was closed as nothing planned, so a default object and scope setting should be used and left running. However, Bob did manage to grab some frames in the clear of M53 until what looks like 3am so that is better than nothing.
Viewing time period – 20:32 – 22:13
Dome has been open a few hours now and the 12″ cooling down with the fans on.
At first the TPoint run was not solving the image, I had to change again the Image scale which was set to 0.01 for the automated TPointing back to 0.32.
Once this was done I started a new TPoint run. The new numbers coming in looked better on the scatter graph, however at about 29 points the mount stalled and the TPoint stopped. So I went out and backed off, turning anti-clockwise the spring screws 1/8 turn on the RA axis. I then restarted the mount, but now it is too late to start again as I have work tomorrow. So I will leave the mount in Bob’s capable hands and head off to bed.
Viewing time period – 21:02 – 04:21
Started TPointing at Point 153, at 22:00 got to Point 231 which gave us 192 confirmed points.
Then went back and did the following points
Point 28 (DONE)
Point 50-55 (DONE)
Point 60 (DONE)
71-92 (DONE)
100-153
101-106 (DONE)
Failed – 107, 108, 112, 113, 130-132,134
Not tried – 100,109-110, 114-118
Completed – 111, 119-129,133,135-152
We had some cloud around 22:45 until 23:29
Throughout this time I processed some Lunar images on the Windows laptop with AutoStakkert from the previous few nights of imaging through the Mak 180. I have noticed you cannot open anything larger than 4GB file size !!
@1:52am TPoint finished
@2:09 GingerGeek took over to look at focuser positions and backlash and autofocus on the Takahashi FSQ102.
Then we started to image M53 on the Tak for RGB data to add to the Luminance data we already have from GingerGeek’s data on the Esprit 120ED.
Tomorrow I will need to look at the TPoint model to refine it!
Addendum ……
So I took a look at the TPoint model and could not get it below 109 inner circle and 200 outer circle without removing a lot of points. So I posted question on the Bisque Sky X forum.
They came back and stated there is something loose in my imaging train or the mount. There is nothing wrong with my imaging train so instead I performed adjustments on the worm gear as they suggested. I will now need to re-TPoint to see if this makes a difference.
Viewing time period – 20:36 – 00:33
Another night of trying to complete a TPoint run. After opening the dome around 4pm to cool down and turning the fans on the 12″ and pulling back the light shield material we (Bob, GingerGeek and I) @20:49 completed Slew and Sync to test plate solving ability which worked well.
We then started the TPoint run.
Our first failure was Point 28 @21:21. The following are other failures.
Failed Point 50,51,52,53 @21:42
Failed Point 55 @21:45
Failed Point 60 @21:53
Failed Point 71,76,77,78,79,80,81,84,85,86,89,
We then performed the first of a few meridian flips back and forth at Point 92
At pointing sample 96 we changed from 20s exp to 25s (20 failed at this point) to see if this helped the failure rate, it helped a little. The sky clarity was not great nor was the 12″ pointing correctly through the dome at the Meridian so need to look at this at a future point.
More Tpoints failed as follows. TPoint 100,102,105,106,107 (at this point scope 1/3 obscured by slit!)
Failed TPoint 109,110,112,113,114,116
By 11pm after 2 hour we had completed 122 points
Failed TPoint 123,127,128,129,130,131,132,133,134,135
@23:39 stopped due to cloud
@00:33 stopped again due to cloud and shut dome but left TPoint session unfinished to see if we can pick up tomorrow night if clear.
Viewing time period – 20:54 – 22:30
Tonight I set out to perform a TPoint run to improve the values we got last October. However it transpired to be more difficult than I thought. We updated TSX after October to there latest release, this seemed to have changed some of the parameters for plate solving. This meant that every time we took an image in the TSX it would not plate solve and so we could not perform the TPoint run. After the best part of 1 hour I gave up and let Bob take over the scope to play.
Meanwhile I then setup the Mac 180 to image Venus, however, by the time I got round to it and found it in the telescope and thus on the chip it was low down the side of the house opposite by the roof and was bumping around badly due to thermals. I found it difficult to centre the scope on Venus with such a small chip so I may need a more repeatable way of doing this moving forwards. I took a couple of videos just for posterity even though I felt the quality would be poor.
Subsequently the following day I opened up the images take with TSX and also download the All Sky Database that was missing to both the NUC in the dome and my local Mac. I then started to change the settings in Image Link within TSX until I could solve the image.
The key parameter transpired to be the Image Scale Tolerance on the All Sky tab setting it to 5% from 1%. Also I changed the Image Scale back to 0.32. On the Setup tab I selected Setup under Source Extraction and changed the detection to 10.0 and the minimum number of pixels to 20.0.
I then tried a second image and that solved in 1 sec too so very happy. I will try to give the TPoint another go tonight as well as Venus on the Mac 180. If TPoint works I will take RGB on the Tak. First solution from the image I solved can be seen below.
The resulting astrometric solution from TSX is below based on another 60s exposure image is below as text.
******* ASTROMETRIC SOLUTION RESULTS ******** Center RA (2000.0): 07h 14m 12.34s Center Dec (2000.0): +32° 34' 16.1" Scale: 0.3250 arcseconds/pixel Size (pixels): 4656 x 3520 Angular Size: 0° 25' 13" x 0° 19' 04" Position Angle: 195° 28' from north through east Mirror Image: No RMS: 0.88 (X: 0.45 Y: 0.75) Number of Stars Used in Solution: 40 (100%) FWHM: 8.98 pixels, 2.92 arcseconds ***********************************************
Things still to resolve
Viewing time period – 18:42 – 04:21
Hoping to perform a TPoint run tonight, along with gathering some frames on M53 through all 3 scopes (along with Darks and Flats for the Esprit), as we only got some frames through the Tak yesterday. I also hope to try out the Mak 180 Sky-Watcher on the portable mount at the same time from the garden. I will also join the BAS Zoom meeting with all the rest of the gang on as we go through the night, which we have been doing for the past 11 days due to this unprecedented lockdown of society globally due to the Coronavirus, Covid-19 SARS-Coronavirus2 outbreak.
So progressed well tonight, spent the whole night on Zoom with the other astronomers so good company. Managed to image the following Lunar 100 objects, L13 – L30 – L42 – L53 – L59 – L65 – L68 as well as Venus which was at a phase of 44.75%.
@23:53 finished imaging with the Mak 180
Unfortunately M35 has now set and Bob is still imaging the Moon so I will have to grab M35 tomorrow early if it is clear……
I saw big problems with calibration with PHD2 which need to be looked at on the Tak.
@4:21am went to bed whilst the IMT3 was taking Darks
Things to still resolve
Viewing time period – 18:56 – 00:59
So early on as always I opened the dome to cool down. Tonight Bob, Gingergeek and I want to image Venus in the Pleiades. Even before it got dark and as I slewed the telescopes to Venus, it was visible straight away so I took a quick image, 0.001s from both the 12″ and Bob’s FS102.
I then went off to watch TV with Helen whilst Gingergeek and Bob grabbed some more images of Venus.
Around 10pm I re-joined Bob and GingerGeek and we set about imaging Venus as it passed by M45 Pleiades in the Tak FS 102. We then went on to perform autofocus on the Tak followed buy setting up the autofocus on the Esprit 120ED
Before the clouds decided to put a stop to play, we took some images of M53 the globular cluster on the Esprit around 00:10am using the Luminance filter.
By 00:59 the clouds finished play 🙁
Viewing time period – 20:30 – 22:20
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.
The mount in TSX and SGPro are now synced to the correct position in the sky.
Viewing time period – 17:18 – 02:07
Cooling down telescope ready for tonights viewing
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.
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.
@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.
@22:32 I started on the RGB frames for NGC 3395/3396 after refocusing on the Red filter.
@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.
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.
@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.
Things to still resolve……..
Viewing time period – 19:15 – 23:05
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.
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℃.
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℃.
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.
