GingerGeek came round again tonight for another full night of imaging.
Focus position at 19,506 for Luminance at 22:30 hours.
Started with M100 a galaxy in Coma Berenices. LRGB at 300s sub frames as I have not imaged this galaxy before. However I found this was too close to the Moon so I will revise another night. So I moved onto M10 for RGB, as I have luminance data from Spring 2020 I took 4-6 of RGB as M10 was then too low as it passed the Meridian.
Unfortunately due to the Moon and on reflection looking at the luminance data from April none of the data is of significant quality to be able to use, so I will have to reshoot.
M101 for me this evening to try and get there RGB data in one night. GingerGeek has come round to test out his travel setup, he has a Takahashi FSQ85, QHY268C and the Pegasus NYX-101 harmonic mount.
Focused at 20,105 on Luminance so RGB will be 21,105
1 x 300s Red
Taking 2 minute exposures for each colour at -25℃. I then realised 5 minutes is so much better. So at 1:30am I then started exposing at 5 minutes with the plan to combine both data sets. The SkyX worked brilliantly as can be seen below, looking after the guiding and image capture.
The main challenge I had early on was the the dome shutting unexpectedly. I will attempt to find out why over the next few months. The camera noise continues to be an issue but less so tonight so I think it may be USB related, again I will troubleshoot and check there cable lengths.
GingerGeek had a productive night troubleshooting a multitude of problems on his untested travel kit and was pleased with the results including taking his first image of a supernova in M101.
Imaging from IMT3b this evening using the 12″ CDK. Decided to test and see what my image scale would look like compared to Bob’s 17″ CDK. Bob had recently taken an image of Hickson 68 and in particular NGC 5353, a spiral galaxy in Canes Ventatici.
So I’m out and all is clear and calm, temperature is around 12℃ after a pleasantly warm day of 21℃. I am now shooting 1 minutes exposures as did Bob and I will take 70 of these. Of course to be comparable I would need at least 4 times the amount give the light grasp from Bob’s 17″.
By 1.13am I had finished 70 x 60s exposures for NGC 5353 including flats and darks. Then I slewed to M101 to start collecting RGB frames, however I needed to get the camera rotated back to the right position. Firstly PixInsight’s plate solving script had gone from my install since the recent update so I need to fix that. So instead I used image link in TSX. Using the following process I managed to correct my FoV frame and then sync the rotator to the current view. I then opened the M101 image from the 21st April and used that as a reference to then rotate the rotator to align.
Take a photo and Image Link it
Rotate the FoV Indicator to match the position angle and synch it
Unlink the image
Open the original M101 photo
Rotate the FoV Indicator to match the linked photo and tell the rotator to rotate
Finally got the imaging run on M101 started at 3am for RGB taking 2min subs. I remembered to move the focus position out by 1,000. So I went from luminance at 19,329 to Red 20,329
Out imaging M101 in Luminance again to gather more data before I move onto RGB. I already have some Ha which to be honest is probably not all that useful due to poor signal.
5 mins exposure of M101 uncalibrated
So admittedly the biggest challenge tonight was not having sorted automating a meridian flip, falling asleep and waking up after 1 hour to find I had 50 mins of star trails as the mount had come to a perfectly safe rest and stopped tracking. A quick manual flip and I was back in action
Not tracking at the meridian
Another problem I had, especially on the West side of the meridian was a jump every now and then in the autoguider causing the resulting image to have a jump in it. I eventually suspected the star brightness of the guid star being the issue so I increased the exposure from 7s to 12s. This resulted in an increase in the Relative Star Brightness as shown on the Autoguider Graph increasing from 40 to over 100. It also seems to have resolved the issue.
Relative Star Brightness increased with increased exposure 7s to 12s
The last problem I had tonight was the camera was set to GAIN 139 OFFSET 10 rather than OFFSET 21. This seems to reset in TSX every time I reconnect the camera. So from now on I will make it part of my startup process to set the OFFSET correctly. The impact is slightly dimmer pixels as it is not adding the additional 11 to each one and thus the times for Flats I have need to be increased.
In total tonight I managed to grab around 4 hours 15 mins of good data once I removed problematic frames so 51 x 300s subs. I also took calibration frames, darks, flats and flat darks.
After a successful morning of Luke helping me rewire the 12″ due to the removal of all computers apart from the Mac Mini, I looked at why the guider kept disconnecting last night and then not calibrating. It transpired to be the length of the USB run. I was hoping through 3 hubs and many meters of cable. On replacing the cable with a shorter one and plugging it into a single hub, the connection error went away. The only thing left to do was test auto guiding at night.
So roll on evening and I went out early to catch the first starts. Luke and I had replaced the All Sky Camera during the day so we wanted to see what that looked like, It is fair to say the ZWO ASI178MC is an amazing upgrade to the rubbish little ZWO ASI120MC I had been using.
New ASC with wider lens
So after much messing about with trying a camera other than the SX Lodestar, trying several pieces of software including PHD2 that I could not get working, I settled on TSX for guiding and managed to get it calibrated. On swapping the side of the mount and recalibrating I had a similar problem, however I think the brightness of the guidestar, along with the exposure time and the order I was doing things in had caused the issue.
Below are the settings used for the working system, note the calibration distance is 30 arcsecs which is fine if you calibrate on a star rather than a hot pixel.
Relay Settings including Direct Guide! 30 arc seconds for calibration distance
Successful calibration East side of mount
Successful calibration West side of mount
Guide Target Method
Settings
X2 Plugin and remove hot pixels
Autoguide tab – long exposure and subframe selected
Before sunset I wanted to reset the dome parameters in TSX as these had got corrupted since loosing the NUC. I now have a set of working settings.
So I have managed to get the dome rotation working. The settings can be seen here for the OS12 and are documented for the other 2 scopes which are piggybacked in my TOSA manual.
OS 12″ Dome Settings
Skywatcher 120 Esprit Dome Settings
Skywatcher 5″ Dome Settings
Serial Device used for Dome
Unfortunately the night did not produce any images as the last thing I could not get working was guiding, I will take and look tomorrow. The main problem was I could get TSX, PHD2 or a 3rd party piece of software to calibrate the guider.
For a long while I have had the observatory turned off. All the computers, mount and dome, due to the energy crisis. However, tonight I wanted to make sure the dome still worked and I could image an object so I turned most things back on. There are some things I can do without, including the ASC.
I managed to fight with SGPro to get it to image and slewed to the Soul Nebula. In particular a star galled GSC 4048:1298 which is near a nice Ha region. I found a guide star through the off axis guider and set about imaging 600s subs. I took around 7 before the dome closed due to the moon being so bright the weather statin reported it being too light to image! So the dome closed. I did reopen and get some more data but now it is too late and I need some sleep for work.
Another go at Jupiter tonight. The jet stream from netweather.tv is out of the way. I got really good focus. I managed to use the atmospheric dispersion corrector and get good alignment of the channels. I then took a mixture of 90s and 120s movies. I stacked in Siril and process in PI all on the Mac. So seeing has been my real problem.
GingerGeek came over again and we setup on the patio. I then waited for the clouds to clear at 12:30am before I had 45 mins to capture Jupiter on the Mak180 without the barlow. The jet stream (https://www.netweather.tv/charts-and-data/jetstream) was much better tonight so I could get better focus and the detail on the planet looks better with glimpses of the moons showing.
Back for a second night tonight. M26 is the target again to get some more quality data on the open cluster.
I will set the camera back to Gain 10 Offset 10 to allow for maximum exposure with minimum star saturation. I have had some cloud this evening so far which caused the dome to close. Now it has cleared I have reopened.
Focus run at 22:04 gave 15,965 on Luminance. I left the observatory running at around 12:30am and headed off for bed.
I noticed in the morning the dome had closed and the imaging stopped 40 mins before completion. There may have been clouds so I will check the rest of the frames later. I should have then refocused again later as it drifted again. I reviewed the LRGB frames however the guiding was not brilliant and some of the frames have trailed. I took Flats and Darks in the morning for completeness.
First tonight was to take some 300s darks for the other night for NGC 6765. I only needed 5 of them so spent the first half hour on that.
Then looking at what I could do before the Moon comes up around 11:30pm, I have a couple Messier objects on my list to go after. M26 is the initial one to tackle. I will try a low exposure for luminance and longer on RGB.
Initial focus position is 17,782 for Luminance. I then had to take a new set of darks for the Lodestar camera. I am not sure why these no longer match.
@ 23:53 I started imaging M26 LRGB, L = 60s, RGB = 300s
M26 – Red 300s
Focus run at 1:06am 16,879 for Luminance
Finished imaging just before 2am when the object was too low and the bottom of the dome slit was in the way. I then went on to grab flats and darks.
M96 galaxy in LRGB on the 12″. Focus position 20691. Started at 22:29. Set up for 4 hours before it disappears behind the trees on the West side of the Meridian. Looking to take 24 x Lum and 8 x RGB all at 300s. Left the dome running and off to bed.
M96 Luminance 300s
The next morning I reviewed the status of the dome and imaging run and it ran al night without a glitch which was great. However the focus drifted quite considerably so I will need to throw away some of the data. What I need to do is cool down the observatory and the mirror before hand which last night I did not due to the last minute decision to image. Also getting the temperature compensation working on the focuser would help, so maybe time to revisit.
I will do another run on M96 on the next clear night.
Tonight is a synchronous group observing campaign with Exoclock. We are going after an exoplanet around star Tycho 1962:0303 / HD 82139. I note that HD 82139 does not come up in TSX but the Tycho star in the right format does. I tried to install the 6GB USNO B database but it fails with an error that the files are not all in the directory. I will try to sort this out later.
Start of transit was 22:28 BST Mid transit 23:37 BST , End of Transit is 00:47 BST, 1 hour after transit is 01:47 BST
I had an initial problem after starting the imaging run, the focuser went back to 14000 again which meant I was out of focus. I only noticed later and then restarted, fortunately before the start of the transit.
Reviewing the files the following evening I noted the dome closed around 00:40 so 7 mins before the end of Transit. I have no idea why the dome closed…….
M36 with Esprit 120 from the dome until 23:45. I took 60 x 60s and 60 x 120s to try and reduce star satuaration.
M36 60s exposure
To guide on the 12″ tonight I realised the camera was not in focus, so I connected the focuser and moved from pos 14000 to pos 21000 which allowed me to get a much higher than 25-30 star signal to noise ratio SNR than before when it was sub 10 and this guided perfectly with perfect star profiles too.
I then went to bed, awoke early at 1am and set the Esprit imaging M59 and took 36 x 300s before heading back to bed. The imaging stopped at 4:35am. Later in the morning when I awoke I took Flats as I had darks from the other night.
Opened the dome and setup the 22″ Obsessions telescope for visual.
I have gone with a recommendation of Mark Radice this evening andI will both image and perform visual on M46 including the planetary nebula Herschel H39-4 that resides within it.
So with the 120 Esprit inside the dome imaging away on M46, now that it is to the East of the Meridian, I connected the Argo Navis to the 22″ and set about aligning the scope. After a few minutes and with the alignment complete, I pushed to M46.
M46 Observing Notes
31mm Nagler 75x Mag. M46 Open Cluster fills the view. Apparent instantly is the planetary nebula Herschel H39-4 towards the 5 o’clock position. A small ring can be seen with direct vision and with averted vision the contrast increases. I am not using any filter yet.I can resolve many stars. With the 13mm Ethos 180 x Mag H39-4 becomes much larger and you can resolve easily the star within the centre of the ring. Now only several handfuls of stars can be resolved.
M42 Observing Notes
31mm Nagler 75 x Mag. M42 steller nursary and hydrogen nebula is very bright with the wings sweeping outward. The trapezium is clearly seen. With averted vision much more gas is forthcoming around the area within the FoV. Moving to the 13 Ethos 180 x Mag the trapezium is resolved pleasantly into a much wider set of 4 stars. The hydrogen gas now takes on structure and lingering on this one can make out dark features within it give the nebula a 3 dimensional feel. Now you experience a warm glow within the eyepiece that seems to draw your eye towards the gas in which the trapezium stars sit.
At this point I cam back into there Warmroom to write up my notes and review the images being taken in the observatory. I have now taken 21 x 300s of M46. Now switching to M48.
I then joined the BAS Zoom call to speak with Derek, Nigel, Bob and Mil Dave. We discussed M44 taken by Bob and suggested if I could see the UGC 4526 galaxy. So I went out to take a look.
M44 and UGC 4526 from Bob
M44 Observing Notes
Looking at M44 with Nagler 31mm at 75x Mag…..
I landed up finishing M48 at 23:47. I took 30 x 300s but then checked through the last few when the dome closed and I actually got 26, I might have lost the guide or the dome slewed incorrectly or shut, not sure which.
Addendum – It turned out to be loosing the guide star and because the camera wears not in focus, so connecting the focuser and moving from 14000 to 21000 position fixed it. The star profile was much better and SNR was 25-30 instead of 10.
After a presentation to BAS on the Obsession 22″ I opened the dome and set about imaging M61 RGB. I managed to take 6 x 300s of each channel at Gain 139 Offset 21 Temperature -25℃ before the dome closed around half past midnight, not sure why.
