IMT3c – IMT3b Observatory

Viewing Report 24th& 25th June 2023

23:00 – 02:00

4 Epsilon Lyra Double Double star – 31mm I can see the double but not split the 2 stars; 13mm Ethos allowed me to split the doubles and the 10mm whilst slightly dimmer afforded me a slightly wider split

Cat’s Eye Planetary Nebula – 31mm very small not quite pinpoint of light visible nicely without a filter, OIII filter makes it slightly more apparent and Nebustar filter it looks marginally better; 13mm Ethos provided brighter nebula, again the filters provided a better view with the Nebustar being brightest; 10mm is the best view of them all with a definite oval shape East or West, right to left but now OIII produced the brightest and clearest view although it is pushing the seeing tonight

Turtle Planetary Nebula – Not seen

Rasalgethi Alpha Hercules Double Star – 10mm too much for tonight, could not get good focus but could easily split; 13mm Ethos the best view with brighter primary in yellow, very striking and smaller secondary blue; 31mm Nagler just splittable but both components look yellow.

Albireo Double Star – Bright large yellow primary and smaller but still bright blue star in the 13mm Ethos

M13 Hercules Globular Cluster – lovely in the 31mm Nagler; 13mm Ethos much brighter view and obviously larger with resolving more core stars; 10mm darker background so contrast better and even brighter core and stars more obvious with direct vision, including nice pair at 10pm on the cluster

M57 Ring Nebula – planned but not attempted

61 Cygni Double Star – planned but not attempted

NGC 6891 Open Cluster in Lyra – not seen in 31mm Nagler

NGC 6702 & NGC 6703 Galaxy pair – planned but not attempted

M56 Globular Cluster – 10mm dim resolvable , 13mm slightly brighter resolvable averted vision

NGC 6765 Planetary Nebula – planned not attempted

A really good night overall, the eyepieces lent to me from Bob are excellent and make the viewing more pleasurable being able to switch with my wider field of view ones.

Viewing Report 13th June 2023

23:00 – xx:xx

So the 22″ Dob is still out of action with the encoder cable needing repairing from a recent issue with snagging. I’ve ordered some RJ9 connectors to replace the one on the RA axis that is broken. So instead I thought I would open the dome and given the perfectly clear weather with no chance of rain, I would image Arp xxx with the 12″ that Bob Trevan had recently imaged with his 17″ and leave the scope running.

Due to the brightness of the sky when I started it was impossible to find a guide star, thus I have decided to perform almost lucky imaging of 1min exposures. Again given the background brightness this time of year, if I were to try lucky imaging of this faint object of say 1/10th of a second, it would not appear.

So I have set the scope running with 240 images to take in luminance and will come back in the morning and check the results.

Viewing Report 10th June 2023

22:34 – 01:00

Tonight was a visual night. GingerGeek and I used the 22″ Obsession Dobsonian to view some of the wonders of the late Spring sky.

We started with Venus with the aid of a Moon filter. Whilst Venus is bright and not too overwhelming in the eyepiece, the contrast afforded by the addition of this particular filter aids the clarity of the image as Venus sits on the bright backlight of the night sky this time of year. Venus is in a gibbous phase and you could clearly see a concave arch to the edge of Venus that was missing. The seeing was very steady and we were able to push to 179x with the 13mm Nagler.

Next up was Mars. Whilst it took a while for it to appear in the astronomically twilight sky, I swept the area North East of Venus and landed the target after a few moments. Mars was so very small compared with Venus, obviously red as seen without a filter in this case and slightly shifting in colours due to the seeing. By the time we had finished looking, Mars had appeared in the night sky.

Now the sky was getting darker we wanted to start on the deep sky objects. It became apparent very quickly there was a problem with my alignment. This was a problem I faced the last time out and the trouble is with he RA encoder. The RJ11 cable has been pulled and needs recrimping. So for tonight it was about star hoping only 🙂

We then went on to look at globulars M3, M92, planetary nebulae M57 the Ring nebula and M97 the Owl nebula. We tried to get M101 but the sky brightness would not allow it. We also looked at Mizar and Alcor that I could see from 11:30pm as a double, and we looked at Polaris and it’s double star companion SAO 305 through the scope.

The planetary nebulae were seen through an OIII filter and Tele Vue Nebustar filter. I thought the view was slightly clearer through the Nebustar filter, maybe due to the slightly wider bandwidth which includes H-Beta. The Ring nebula was very crisp and I thought I could discern the central star which is 12th magnitude. Our friend Bob was kind enough to lend me a set of eyepieces he recently acquired. The Tele Vue 10mm Radian eyepiece gives 230x through which we could see the central white dwarf.

Whilst looking at the globular clusters we pushed the magnification to 288x with the 8mm Tele Vue Radian. Both this eyepiece and the 10mm gave fantastic views with the globulars sparking with pinpricks of lights from the 1,000s of Suns!

M101 SuperNova (27th-28th May)

DSW invited me over to the IMT3 observatory for an imaging weekend to image M101 and the recent supernova2023ixf discovery. DSW was using the 12inch RDK and I decided to put the FSQ85 on the Pegasus NYX-101 to test out the setup ready for our Tenerife trip to Mount Teide.

I ran the QHY268C at high gain mode, gain 56, offset 30 and -20℃. I finally managed to cure the noise banding I was experiencing on the QHY268C but using a fully shielded high quality USB3 short length cable that I run from direct to a Pegasus UPBv2 that sits on top of the scope.

Although it’s mid summer and the Moon was bright and approaching full the phase, the sky conditions on the first night appeared to be okay at first sight. Before processing I decided to check on data quality via the blink module in PixInsight it was obvious that they were a lot of unusable subs due to high cloud and using them would have ruined the quality of any resulting stacked image.

Running the data stack of raw images through the PixInsight Subframe Selector to analyse the PSF SNR versus noise it clearly shows that I could only use 7 frames (35 minutes) didn’t drop below 0.08 from night one whilst all the data from night two should go straight into the bin along with most of night one 🙁

Given I don’t have enough data to do the end result justice due to my poor PixInsight skills I decided to invert the images – I really should subscribe to Adam Block Studios (Shout out !)

Inverted image of M101, supernova 2023ixf and surrounding area

Running the AnnotateImage Script labels the various galaxies in the image which I enjoy looking up to see which type they are, magnitude and how far away they are.

Annotated FoV for area around M101, supernova is not labelled

Zooming in to M101 to see the Supernova better, it is located to the right of NGC5461 and indicated by the two arrows.

M101 with SN2023ixf indicated by the arrows

Light Curve

The AAVSO have a light curve plotted from measurements submitted by amateurs, just enter “SN 2023ixf” and submit here. It was still around 11th magnitude on 18th June but there does appear to be a slight decline in the brightness curve.

Viewing Report 26th May 2023 (M101)

22:47 – 03:15

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.

Viewing Report 26th March 2022

19:47 – 03:00

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 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.

FSQ85 Flattener & QHY286C CMOS

I’ve taken the plunge and dipped my toe into the CMOS world. Since I didn’t have any OSC experience I chatted with DSW (has a QHY186c) and decided on the QHY286C. This I purchased from Bern at ModernAstronomy who has always provided excellent service.

The issue with APS-C sensors when coupled with the Takahashi FSQ85 is that the edges start to show signs of star elongation, I already see this on my Atik460. This can be corrected with the FSQ-85 flattener (ordered from FirstLightOptics) which has the effect of slightly increasing the focal length but also reduces the back focus from the native 197.5mm to 56mm.

Effective Focal Length	455mm (f/5.4)
Image Circle Diameter	44mm
Metal Back Focus	56mm

FSQ-85 EDX with Flattener 1.01x

This means that I can’t use my existing Atik OAG->Atik EFW2 and Atik460 because it’s total distance is 59mm (22mm+24mm+13mm) so it’s out by 2mm even once you include the filter effect on the back focus. Note – This is also true for my Starlight Xpress configuration.

I do not understand why Atik could not have got to within the 55-56mm range by shaving off a mm here and there 🙁 I may need to replace all Atik gear when I convert to mono CMOS or replace the OAG with a guide scope.

So onto the QHY268C, the OSC CMOS unfortunately has a CAA tilt adapter instead of a direct thread connection. This wastes 11mm of precious back focus giving a total distance of 23.5mm whereas the recently released QHY286M CMOS has a 12.5mm back focus !!!!

Also the QHY268C does not have an IR/UV cut filter in place so you need to buy an additional filter and holder and add that to the cost and factor in the adapter and distance needed …. I’m starting to regret this purchase more and more !

Back to the Takahashi Flattener (TKA37852), the back focus is 56.2mm but we add on the filter thickness as it changes the light path (2mm/3=0.66mm) so ~57mm (56.9mm), the imaging train is as follows :

Adapter	Distance (mm)	Accumulated Distance (mm)	Connector
OU031	2	2	M54(M) -> M54(M)
QHY 020770	4	6	M54(F)
QHY Spacers	14.4	20.4	screw
QHY OAG-M	10	30.4	screw
QHY 020055	2.5	32.9	screw
inc filter	0.6	33.5	–
QHY CAA adapter	6	39.5	screw
QHY268C CMOS	17.5	57	screw

FSQ85 Flattener to QHY268C imaging train

The combined weight is 1365g so I may need to adjust the balance of the scope a little as it heavier than my Atik460/EFW2/OAG setup at 1080g.

Completed – Imaging train ready for first light

I may have to adjust the spacers a little but I won’t know until I have received a 2-inch Optolong L-Pro light pollution filter which is currently on back order from FLO.

QHY268M

The recently released mono version of the QHY268 looks like it has a proper screw face plate with a more acceptable back focus of 12.5mm. This is more reasonable and would allow me to couple a filter wheel and OAG as well not requiring a IR/UV cut filter.

Like SyedT on StarGazersLounge I could go back to using a guide scope and ditch the OAG and then the imaging train could incorporate a rotator :

Component	Distance (mm)
QHY268M CMOS	12.5
QHYCFW3M-US	17.5
M54 (M) to M54 (M) adapter	2
Pegasus Falcon Rotator	18
M54 extension ring	5
M54 (M) to M54 (M)	2
Total	57

FSQ85 Flattener/QHY268M Imaging Train – Credit SyedT

I was thinking of a rotator for the remote Esprit120 which has a generous back focus of 76mm so I should have no problems there but that will be another adventure for the future !