Blog – Page 3 – IMT3b Observatory

Imaging Report 15th-16th December 2022

As it was a work night and Dave was working I was imaging from the back garden and not the dark site. I started late in the evening and had issues sorting out the autofocus in NINA which meant I was even later than I had planned.

Using the OptoLong L-Pro filter and the native camera driver (not ASCOM) :

The target was decided by Dave as M31 (Andromeda Galaxy), I decided on 120 second exposures at -15℃, gain 0 and offset 30 (Photographic Mode). I finally started to capture data at 19:55 when M31 had already transited 45 minutes earlier.

M31 single sub (stretched) via NINA Imaging Session

I believe the dark shadow to the left is the QHY OAG prism, I may have to reduce it’s depth in the light path or rotate it 45 degrees so it sits on the long horizontal axis.

Once M31 had reached approximately 50 degrees altitude and was starting to set in the West my guiding started going awry especially in RA. I put this done to either balance issues or cable snagging so that’s something I need to look at in the future.

After shutting down earlier than I thought due to the guiding issue and the pending rising Moon I decided to do my darks, flats and dark flats. However my Pegasus Flatmaster refused to connect to NINA so I decided to fix and complete this task on a different day.

I only managed to capture 62 subs which totals just over 2 hours. I was hoping to get at least 6 hrs for a single session and something approaching > 12 hours which means I will need several more nights to capture my required amount of data for M31.

Not a great first outing but given I hadn’t imaged in ages this was expected. I can honestly say that although a OSC coupled with the new harmonic mounts such as the ZWO AM5/Pegasus Nyx are very convenient as part of a lightweight holiday travel setup. OSC also is easier processing but still I can say I’m not a total fan due to the loss of high frequency data, high HFR focus issues and in the case of the QHY268C the noise banding issue which although appears to be removed by darks etc still is unnerving.

Update (17/12/2022)

Have resolved my Flatmaster 120 panel issues but I feel I’m better off with a fully controllable fixed panel instead of a manual panel so I will look into that.

My Darks, Flats and Dark Flats are now done (25 of each) all performed at -15℃ to match this session temperatures but there is still not enough actual data to start processing.

Equipment Check-up

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 :

https://www.youtube.com/watch?v=BfvmlR3It1o

Viewing Report 10th December 2022

23:00 – 00:20

So it’s about time I tried to find a replacement for SGPro, given the continued problems with it, it’s less than intuitive design and find something that does not cause friction in my desire to capture more photons from the distant universe! So after looking at NINA briefly earlier this year, I have gone for it this evening to see if I can indeed capture some images.

The problem that set me back once before with NINA was the lack of connection to the FLI focuser. I just simply got an ASCOM error (I really dislike ASCOM). So after some educated guessing I got it connected. Instead of connecting to the FLI focuser directly I actually went through ASCOM which bizarrely cured the error.

With that done. I could now run autofocus, and only the 2nd time in my life this astronomy programme focused on the first go. The only other piece of software that good is the ZWO ASIAIR that I really enjoy because it just works.

I have now connected NINA to PHD2, also to TSX and left TSX to control the dome. I may change this later, however it works just fine and has not caused any problems. The only reason may be to further automate the dome for closing and reporting on status if that is a feature of NINA, something to look into later.

Managed to take 5 or 6 Ha images of 600s this evening before the cloud rolled in. I can use the flats from yesterday. A good evening testing given conditions including the almost full but waining Moon.

Viewing Report 9th December 2022

19:01 – 03:05

Dome open on the freezing night, currently -2℃, and I have fixed the dome slipping for the 2nd time this week, this time putting new grip tape on a hole that had appeared due to the wheel slipping.

Started out imaging M76 which is near the Zenith whilst we watch Harry Potter in the warmth of the lounge buy a roaring fire. After 11 frames of 600s in OIII I have stopped and slewed through Meridian flip and now started on Ha as I have 84 frames of OIII already……

So at 1:15pm I had 23 x 600s Ha on M76. Whilst I need much more and then RGB frames, I want to go to bed and M76 will set shortly to a less than desirable altitude. So I took my flats, darks and flats darks and closed the dome up for the night as the Moon was still fairly full.

Viewing Report 8th December 2022

19:43 – 22:29

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.

I took flats, darks and flat darks.

Viewing Report 24th September 2022

23:45 – 01:43

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.

Ganymede, Jupiter and Europa (left to right)

Viewing Report 18th September 2022

21:00 – 02:20

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.

Viewing Report 16th September 2022

18:45 – 03:38

Imaged Jupiter all night. The last few videos were with the barlow out.

Finished imaging around 03:38, the humidity had got very bad, around 90%

GingerGeek joined me

Viewing Report 27th August 2022

21:49 – 23:32

Not entirely clear this Bank Holiday weekend, however good enough to test out the newly cleaned ASI1600MM with the new desiccant. I received the desiccant from Zoltan at Astronomy365 and cooked in the microwave for 2 mins on medium power before letting cool down and then placing in the camera. I managed to get most of the dust off the sensor, however it is very difficult.

At 00:15 I started to image M72 the globular cluster low down in Aquarius using LRGB 60s on Luminance and 300s on RGB. Note that I will need all new flats today due to the cleaning of the camera. I will leave the observatory running overnight and head off to bed.

Update from this morning, looks like the observatory run all night without a problem and however I believe the object went behind the trees in the distance that have grown after about 10 luminance frame 🙁 I took flats this morning and will take darks tonight.

Flats – Done

Darks – Not done

Viewing Report 20th August 2022

20:36 – 00:39

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.

Viewing Report 19th August 2022

22:43 – 03:06

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

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.

Viewing Report 7th August 2022

22:30 – 02:37

Tonight John Barrie-Smith and Bob came round to observe with me from Mirador Ellisfield. The temperature has been warm +24c and the humidity average. I assembled the 22″ dob and brought out the 100mm binos.

Bob had a pair of tiny binoculars which whilst we were waiting for darkness to arrive we thought we would try them out. To our surprise when looking at the Moon we could see a star to the East which transpired to DSschubba, a mag +2.2 star in the constellation of Scorpius. This is top star above Antares in the scorpion. This was unseen with the naked eye.

We then realised that the Moon was going to occult this star and that we could watch it happen. So with Bob on the Binos, JBS on the 22″ and I with my Canon 6D with the 300mm lens, we set about watching the event.

We caught the star being occulted by the Moon, but then we struggled as the Moon was setting behind the trees in the distant forest. However around 22:13:20 the star reappeared just as the Moon was setting around +4 degrees altitude. A good result!

Moon setting with the star hidden behind

So after a thrilling and unexpected chase, we set about using the 22″ for some visual. I had started SkyTools 4 for the first time earlier in the day and created my first observing chart. I printed a list of objects to go after and we used this to work through some very appealing and easy targets.

M21 was seen by JBS and I before it quickly set behind a tree, however this open cluster looked great.

M102 was easy to see with direct vision. This galaxy looked splendid through the 13mm Ethos eyepiece. This was a long thin galaxy with a slight bulge to the centre. Whilst SkyTools did state the 24mm Panoptic was the best eyepiece to see this with, we felt that the 13mm Ethos was a good option and provided the best view.

John then wanted to go to M101 the Pinwheel galaxy. This is a face on spiral that has a low surface brightness and was rather hard to see. We tried all 3 eyepieces, so the 24mm Panoptic, 13mm Ethos and 31mm Nagler. To prove that this was because it was a harder object to see with relatively low surface brightness and thus did not appear on my SkyTools list of Easy and Obvious objects to see, we set about looking for M51 with it’s associated NGC NGC 5195 interacting galaxy. This was as we noted fairly faint to see also but rather distinct with the 2 objects being visible.

We also looked at an open cluster called the Cooling Tower, M29 or NGC 6913, Bob could see the cooling tower in this little cluster of stars which was bedded into the Milkyway’s rich star field.

We then looked at the Blue Flash nebula, NGC 6905 which did indeed resemble a flash in the pan of oil.

We then went to M5 a glob that was very low down and did appear on the list. The scope was all but horizontal but provided a good view despite the seeing.

Finally we stole a look at M13 which was to compare with M5 and wow it was really bright and steady and the details of the stars within especially with the 13mm Ethos were amazing. It is worth noting that it was fairly high in the sky unlike M5.

Once Bob and JBS packed up and went home around 12:30am I slewed the 12″ in the dome to NGC 6905 the Blue Flash and too a single 2 min Luminance exposure to see what we had seen.

I then loaded my sequence for NGC 6765 and took a set of LRGB and OIII 300s exposures, x 5 each until 3:45am. I left the scope running until morning and went to bed at 2am. A really good night with friends.

NGC 6765 Planetary Nebula by the arrow 300s Lum

Compressing FITs files

In the days of consumer high capacity storage things look great but modern CMOS cameras output fairly large sized FITs but coupled with short exposure sub one evening can result in a large amount of data to process.

So various solutions are available – block compression and byte compression. Taking one FITs image (test.fit) from a OSC CMOS we can compare different compression methods.

Windows Compression

Using the built compression accessed via a file’s advanced options the file is reduced from 49.8MB down to a 43.5MB of disk usage.

Gzip compression

Using the Linux gzip compression utility (v1.9) we perform a byte-level compression in userspace.

# cksum test.fit
4076709869 52223040 test.fit
# gzip -9 test.fit
# ls -lashi test.fit.gz
524306 33M -rw-r--r--. 1 root root 33M Jul 15 14:34 test.fit.gz
# du -sh test.fit.gz
33M     test.fit.gz
# cksum test.fit.gz
1554386539 34046021 test.fit.gz
# gunzip test.fit.gz
# cksum test.fit
4076709869 52223040 test.fit

Gzipping the 50MB fits files results in 33MB of disk usage. Using fpack (v1.7.0) results in similar results and the file format (fit.fz). The fit.fz file is supported by the processing tool Pixinsight.

# fpack -g -q0 -v test.fit

Block Compression

Here we utilise the block-level compression feature of IBM Spectrum Scale Developer Edition.

# ls -lashi test.fit
524305 50M -rw-r--r--. 1 root root 50M Jul 15 14:34 test.fit
# du -sh test.fit
50M     test.fit
# cksum test.fit
4076709869 52223040 test.fit
# /usr/lpp/mmfs/bin/mmchattr --compression z test.fit
# ls -lashi test.fit
524305 36M -rw-r--r--. 1 root root 50M Jul 15 14:34 test.fit
# cksum test.fit
4076709869 52223040 test.fit
# /usr/lpp/mmfs/bin/mmchattr --compression no test.fit
# du -sh test.fit
36M     test.fit

The compression is transparent to the user application and user and they seen as the original file, modified files will need to be recompressed. As this is at the file system block-level the checksum is the same if the file is compressed or not.

Pixinsight XIF Compression

Pixinsight offers the XISF format as an alternative to the FITs format. Existing FITs file can be converted to XISF using the BatchFormatConversion script. To utilise compression you need to supply the appropriate output hints.

The process console output shows the resulting size of the converted FITs image being reduced to 49% of its original size.

Conclusion

Pixinsight XIF compression gives the best compression but the issue is that it is currently not currently an accepted standard and other utilities (astropy) do not have the ability to read them. Pixinsight can also read fit.fz files

NINA can save camera files as FITS or XISF, the XISF method offers LZ4, LZ4HC and Zlib compression but no gzip/fpack option for FITS.

For now I will continue to compress FITS to fit.gz or fit.fz to give me the benefits of space savings whilst still allowing me to use the data across Windows and Linux utilities.

Viewing Report Thursday 30th June 2022 Tenerife – Parador

21:30 – 06:30

First of all tonight I have taken darks for 300s that are needed for the earlier data. However I am still suffering from the QHY168c disconnecting from the laptop, this time in TSX. I have upgraded the software yesterday but this has not made a difference, so it must be something to do with the way there USB cable is connecting. I will attempt to troubleshoot when I get home. Right now I have switched to Ezcap again which seems to be ok.

I have setup over by Mark and will see what this location is like behind the pool building. I have found that the WiFi is weak or non existent. Also the staff room is nearby and the light is constantly on so maybe not the best place to image from.

@00:03 NGC 6352 30s -20℃ I took a single exposure of this.

@00:19 LDN 10 30s -20℃

@00:42 Haumea 30s -20℃

@01:26 Makemake 30s -20℃

@01:52 Pluto 30s -20℃

@02:33 Eagle nebula 30s -20℃

@03:45 NGC 6520 &| B86 30s -20℃

Viewing Report Tuesday 28th June 2022 Tenerife – Parador

22:05 – 05:50

@22:30 Omega Centauri 30s -20℃

@23:17 Centaurus A 30s -20℃

@00:02 M24 30s -20℃

@01:33 M6 30s -20℃

@02:38 M25 30s -20℃

@03:26 LDN 564 300s -20℃

Flats taken

Darks 300s -20℃ (take tomorrow) / 0.35s -25℃ – DONE

Viewing Report Monday 27th June 2022 Tenerife – Parador

22:00 – 07:00

First thing tonight is to complete taking the darks from yesterday, so I need 20 x 120s -20℃, but also the flat darks I forgot for the 0.35ms flats. Then I will move to taking longer images tonight. The challenge with open clusters is that you need short exposures so you don’t oversaturate the stars.

@22:50 Omega Centauri 30s -20℃

@23:20 Centaurus A 300s -20℃

@00:09 Makemake 120s -20℃ x 10

@00:29 Haumea 120s -20℃ x 10

@01:07 M8 Lagoon 300s -20℃ x 24 (focus drifted so review later images)

@03:22 Comet C/2017 K2 PANSTARRS 120s -20℃ x 7

@03:53 M21 30s -20℃ x 90

@05:00 M20 & M21 120s x5

@05:45 LDN 574 300s x 9 which was a mistake

Dark Flats – 0.35s -20℃ – DONE / 0.35s – 25℃ (tomorrow)

Flats – 0.35s -20℃ – DONE

Darks 30s -20℃ – DONE / 300 -20℃ (tomorrow) / 120 -20℃ DONE

Viewing Report Sunday 26th June 2022 Tenerife – Parador

22:55 – 08:00

Finally got our bags today from the airport. Having arrives on the 2:05pm flight and not hearing from BA by 4pm, Lawrence and I headed off down the mountain in search of the 4 missing bags. It took just over an hour to arrive back in the Cicar car park.

Once there we headed inside to be told the the Iberia desk, which deals with lost and late baggage was only accessible the arrivals hall and so we were told to go through the exit doors and not to worry about the police. So we nervously😱 walked through and were greated with the sight of all the lost bags!

It took some 20 mins to sort through the paperwork before we were pushing the bags back to the car for the 1 hour drive back up the TF1 and TF38.

After a hearty dinner, which was absolutely delicious and filling, we headed outside around 9pm to start setting up. This took me the best part of 2 hours to put the gear together after ferrying it from upstairs and then another 60 mins to calibrate and be ready to image. First up tonight is M23.

@ 23:55 started on M23 Open Cluster, 30s -25℃ exposures so not to saturate the stars.

after 87 images escape hung!

@ 01:20 started on M18 Open Cluster 60s, 10 -20℃ or so images this time using TSX to image and then refocused and took 80 images in total.

@ 3:22 started on M26 Open Cluster -20℃ took 68 at 60s

Pluto 4:41am 120s -20℃ I took 10 frames

@5:21 M73 Open Cluster 60s -20℃ took 60 frames

Flats 0.35s -20 & 0.35s -25℃

Darks – 30s -25℃ – Done / 60s -20℃ – Done / 120s -20℃ (tomorrow night) / Flat Darks (tomorrow night)

Viewing Report 1st June 2022

22:40 – 00:31

Visual this evening on the 22″ Dob. The 120 Esprit is still off the MEII so the IMT3b observatory is out of action for a few weeks whilst it is not balanced. The MyT and 120 Esprit are now packed away for the Tenerife trip which is really exciting, first time in over 2 years!

Bob came round this evening and we explored the rather bright sky given the time of year with the dob. So what what did we see?

Observing Notes

M5 seen 23:21 31mm and 13mm better than M3

M3 resolved easily 23:17 31mm and 13mm more compact than M5

M51 massive filled fov in 13mm much smaller in 31mm

M92 seen both eyepieces and very bright

M57 13mm only very large AV central star, very big ring

Viewing Report 27th May 2022

19:48 – 03:08

Tonight is the first night of testing the mobile rig for our 2022 Tenerife BASEG trip. I have just started to setup and am waiting for night to fall. The weather is warm and clear and I am on the IMT3b observing patio.

Tonight is about making sure I can take a set of images and guide and that everything works.

First thing to note is on firing out TSX that I need to change the settings for the mount and select usbmodem1442101 and then connect. This did not work the first time and resulted in an error, disconnecting the USB from the 2 port hub and reconnecting fixed the problem.

Took 44 x 300s on M101 and started to pack up at 3:08 when it was getting light which I could see on the SQM.

Viewing Report 29th April 2022

21:58 – 01:52

Finally the clouds have parted and the stars have come out after what has been a very overcast day.

Focus position at 25592

Slewed to M96 again to gather some more data in focus this time.