So after the shortest time in a house, I have now moved to a much better astronomy home, surrounded by fields and forests, ancient woodland and with some of the darkest skies in the North Hampshire Downs. I am fortunate in my location, however less fortunate that the build of this observatory, unlike my other observatories is happening in the middle of a pandemic of Covid-19. This as you will see makes it extremely hard when you can’t have astronomer friends over to help with the preparation and installation.
The move started to with the dismantling of IMT3 and in the final days at the previous house we dismantled the dome, at least at the time I could have some friends over to the garden to help with Mil Dave, Alan and Shane lending a much needed hand.
Dome has gone!
So on a quick dismantling, which was much quicker than constructing the astronomers put the dome segments on the lawn 🙂
Oh there it is 🙂
However as I found that night when a storm front came through, which caused me and my daughters boyfriend to get up after midnight to secure the dome segments in a more wind resistance piece of the premises.
Wind resistent place
The following day Luke has had his first angle grinding lesson to take out the remains of the bolts and plugs which to be honest I think he really enjoyed.
Luke’s lesson
Then the moving day came and I put all the important scientific astronomy equipment in my old Landy to make sure it got there safely.
12 Inch Officina Stellarie
whilst the rest of the observatory went in a further truck kindly supplied for free by our removal company who are the best removal company ever! Thanks Camberley Removals!
IMT3 tucked up and ready for shipping
By mid November, some 4 months after we accepted an offer on the house I landed up with my new more astro friendly observing location surrounded by fields.
IMT3b Location is a vegetable patch
Next up is removal of the local vegetation and preparing the ground for concreting.
The most funny thing about moving to a new house is assuming you have understood your horizons correctly, well at least I found it funny when I got it wrong. After several attempts to catch the conjunction, traveling out to a nearby field with low horizons, Christmas Eve was no difference. I had set off, this time with the Esprit 120 and QHY168C and on arriving at the location realising that the weather was too cloudy to grab the conjunction.
So off I went back home. I decided to wonder up the garden to see if the weather had cleared when I returned, to find that not only was there a gap on the clouds, but also I could see Jupiter !!! This meant only one thing, that my South West horizon was not +15 degrees but actually +4 degrees! Wow that is good and lucky.
View South West , observatory is going to be in front of the foreground trees
I ran back to the car and started hauling the travel scope to the building site of IMT3b which is currently a vegetable patch, this is around 200 feet away from the car part way down the garden. It took 5 trips to move all the equipment, good for my Apple watch exercise rings, not so good for the setting of the conjunction of Jupiter and Saturn. By the time I setup and slewed the telescope round the pair were setting behind the ancient forest in the distance but I managed to snap a single image! Perfect.
Jupiter and Galilean Moons with Saturn below – 120 Esprit and QHY168CCropped
The weather forecast suggested that this was the only clear night for some time and the planets were low in the sky. So GeekGirl and I wondered if Jupiter/Saturn were visible from the front of the house to the South-West or if we were going to have to traipse over to the muddy farm fields to view the conjunction.
Conjunction View Facing South – Credit stellarium.org
Luckily for us even though they were less than 10º altitude we could see them both between two houses from the front drive. We quickly got some warm gear on and setup the binoculars and the kiddy scope (Sky-Watcher Heritage 150P Dobsonian) on a camping table.
We quickly got Jupiter/Saturn in GeekGirl’s binoculars (Celestron 20×80 SkyMaster). The pairing although not as close as they would be on the 21st still looked nice. The rings of Saturn were discernible and the four Galilean moons were visible in this modest setup and I’m sure the view would be have been better in Dave’s monster binoculars due to the aperature.
Approximate view through 20×80 Binoculars – Credit stellarium.org
In order to get the focus for the planets I used the Heritage 150P on the near half Moon (47%). The views of the craters on the terminator along with the shadows were amazing, we could see the centre peaks of many of the craters.
View via Heritage150P/Super10 eyepiece – Credit stellarium.org
I wonder what they looked like in Dave’s Sky-Watcher SkyMax 180 Pro ?
Our next-door neighbour popped out and we invited him to view the planets and the Moon. I think he was impressed but everyone reacts differently to the experience.
Once we had both wondered over the Moon, checking out the mountain ranges and the changing shades of grey for the Mares we turned to viewing the conjunction in the 150P using the standard eyepieces (SW Super25 & Super10) that came with the scope.
View of Conjunction through Heritage150P – Credit stellarium.org
We could see all four Galilean moons with Io being placed close to Jupiter’s limb. The division in Saturn rings was visible and GeekGirl could glimpse Titan so she was happy. All in all a pleasant experience, which is rare in the current human malware situation. I finished off the evening with a Brewdog IPA ….. bliss !
Dave Shave-Wall viewing
Start time 3pm – End time 6pm
After deciding that I could not get the conjunction of Saturn and Jupiter at the new house, I spent the best part of 40 minutes packing up the travel scope to travel locally to view the conjunction. I set off to view about 1 mile away across a field with allow horizon. I took my Mak180 without the Barlow and the ZWO290MC on the Paramount MyT with the Berlebach tripod. On arriving at the side of the road on the narrow country lane in North Hampshire, I was just about to setup when I realised not only had I forgot the travel car battery, but also the laptop. After a few expletives and a good old English, “I cannot possibly believe I did this, oh well carry on”, I jumped back on the Landrover and set off back home to retrieve the important parts. On arriving back home I ran up the garden to the shed for the battery, grabbed the laptop and jumped back in the car as time was against me for capturing the pairing before they set below the local horizon about 6pm. It was not 4pm.
I arrived back at the field and quickly set about fitting together the mobile setup for the 2nd time!
Field with a view
This time I settled the tripod and mount up in quick time, slide the Mak180 with its imaging train into the Losmandy Versa plate and connected the Mac. I manually aligned on Jupiter which by this time I could see with my naked eye, synced the scope and started the imaging software. After a few back fourths I found Jupiter, however Saturn was nowhere to be seen. It soon became apparent that my field of view FoV indicator on Sky Safari 4 was not accurate and indeed both planes on this particular day would not fit in! So rather than waste the occasion I shot some view of Jupiter and then slewed to Saturn for the same.
Mak180 ready to slew
I then packed the setup away, but before heading off grabbed the Canon 6D with the 100-300mm lens and grabbed a few exposures. My first attempts were not good, having not used the camera for some time and forgetting how to set the correct exposure. After a while I grabbed a single good frame, over exposed to see the Galilean satellites.
Jupiter and Saturn near conjunction Canon 6D 100mmJupiter and Saturn near conjunction Canon 6D 300mmJupiter and Saturn near conjunction Canon 6D 300mm Cropped
I would attempt another go with the larger FoV Esprit 120 a few nights later.
So during the ongoing Human Malware situation we have been concentrating on imaging asteroids, comets and more recently performing exoplanet measurements on the 12inch RC than long exposure deep sky astrophotography.
Astronomy is one those hobbies that is for most part is sole activity for the dark early hours of the morning and these days is usually done remotely. It was therefore disappointing that when one of the team went to use the Sky-Watcher Esprit 120ED for a night of astrophotography and found that he was unable to open the Optec Alnitak Flip-Flat. As the lockdown and travel restrictions progressed due to the initial wave of the human malware situation the issue was soon forgotten as we continued our focus to performing exoplanet observations on the 12inch RC for the ESA Ariel Mission.
Now that IMT3 has been decommissioned ready for it to be reborn as IMT3b at it’s new rural darker sky site I decided to take the opportunity to retrieve the FlipFlat and diagnose the issue at home on my desk.
Using the Alnitak controller software, I could hear the motor running but it never seemed to complete the close or open. All it continued to display was the TIMEDOUT message as shown below.
Timing out !
I sent an email off to the vendor I purchased it from but after a month I got no reply. In the hope I would not be left with an expensive paperweight I reached out to Optec. After quite a few weeks of getting no reply I was pleasantly surprised to receive a message from Jeff Dickerman (President) of Optec. Jeff apologised for not responding earlier and offered to help resolving the issue. The error message seemed to be a known issue and it was generally an easy resolution which required taking the box apart. Jeff sent me instructions on how to take the unit apart and fix the problem.
You’ll see the motor is attached to an internal wall with a modified shoulder screw and stack of Belleville washers. These spring washers are used to allow the arm to slip when someone grabs the lamp and physically tries to force the cover closed. Unfortunately they can also allow the arm to slip during an open or close operation which leads to that dreaded “TIMED OUT” message. Optec have redesigned the stack a bit to eliminate this issue going forward.
To correct, you might be able to adjust the washer stack by removing the lock nut and sliding off the washer stack to the pivot arm. Check carefully to see if the shoulder screw protrudes beyond the pivot arm. If so, rather than installing the cork washer next, install a 5/16” ID washer first to cover the exposed shoulder. Next add the cork washer and stack of Belleville washers. Finally screw the lock nut back in place and tighten while holding the shoulder screw near the motor (this is important to avoid breaking the internal motor gears).
Step 1 – Pry open clamshell
Step 2 – Shows what to secure
Step 3 – Tools needed
Step 4 –
Step 5 – Check shoulder visibility
Step 5a – Shoulder
Step 6 – Washer Stack
In the end I decided to courier the unit back to Optec for repair as I did not want to render my unit completely useless in case I made a mistake.
I’m extremely grateful to Jeff, Tina and the team at Optec for all there help, patience and understanding. I’m a very happy customer and the flip-flat will be rejoining the Esprit120 when the IMT relocation is complete at it’s new rural location. I can then do a Homer Simpson and annoy Dave with “Flap goes open, flap goes shut, flap goes open ……”
So we started the decommissioning of IMT3, dome and all ready for the move to a new darker site location. The new incarnation once installed will be known as IMT3b. As part of the process the Esprit120 will be relocated to a separate pier mount in a RoR shed to be known as IMT3c.
Decided to have a quick look out before moving house, given it was supposed to be cloudy and there is a bit of a clear spell. I have decided to just take a look at a few objects. First up is the Cheeseburger Nebula NGC 7026.
Next up is IC63 which is a ghost nebula that Tim imaged the other night, I want to see what it looks like in my 12″ vs his 10″. The first thing I noticed was in the guider window that the reflection of the bright star Gamma Cas caused an interesting image.
Guiding reflectionGamma CasIC 63 Ghost Nebula 10min Ha
Next I am going to go after M110.
M110 5 minutes Luminance
I have now slewed to M32 just below.
M32 5 minutes Luminance
The last object of tonight and then off to bed so I can be up to help Bob concrete IMT4 tomorrow is NGC 508.
Imaging with GingerGeek for another exoplanet. This one starts its pre-transit at 23:55 and should just about be on the point at the meridian where we can perform a meridian flip and then image all night.
We like to make sure we have the right star field so actually having a photo from the exoclock website helps. Tonights candidate is the dimmer star to the left of this pair.
The star is a magnitude 10 star in Lacerta. Unfortunately despite the forecast it has just clouded over, here is what we would have been imaging.
So the evening started well, I had logged into IMT3, got the dome ready, TheSkyX/SGPro software was up and running, CMOS camera was cooled and I was already syncing on a bright star even though it was still twilight.
Dave and I had chatted the previous night and had settled on HAT-P-32b in the constellation of Andromeda. The reason was due to the target position in the sky, the time of rising and setting was before the rise of the sun so we could get a full ingress and egress and no meridian flip was required.
Then the gremlins started to play havoc with our efforts and I was having major issue with guiding to the point that I was going to give up as the issues were eating into the desired 1 hour egress monitoring time period. Dave joined the session to help resolve the issue and we managed to start imaging about 10 minutes before the start of the transit.
Dave had to go to bed due to work commitments but I was determined to get the full set of observation and run it through the HOPS analysis software. It was an uneventful night interspaced with music, movies and hot cups of tea.
Once I had transferred the data over the internet to my server, performed the analysis and sent the result to Dave it was 5:30am so I crawled into bed around 6am.
Bob, Dave and GingerGeek playing with the Tak 102 this evening and just image for 2 minutes on various targets.
Slewed to the Double Cluster first.
Focus position was 564 from the last time we used it a long time, it is now 578.
Took a 2 minute exposure
Double Cluster
Slewed to M75 the Little Dumbell. Needed to take a 5 min exposure to see
M76 Little Dumbell
Slewed to M34 Open Cluster.
M34 Open Cluster
Slewed to NGC 1023 a barred spiral galaxy. Took 5mins exposure at 22:12.
NGC 1023 Galaxy
GingerGeek went off to bed whilst Dave and Bob continued.
Slewed to NGC 1260 a lenticular galaxy in Perseus.
NGC 1260 Galaxy
Slewed to NGC 1545 an open cluster but it was behind the house.
Slewed to IC 1848 the Soul nebula.
IC 1848 Soul Nebula
Slewed to Heart nebula.
IC 1805 Heart Nebula
Slewed to IC 1831 an HII cloud.
IC 1831 Nebula
Slewed to IC 1795 nebula.
IC 1795 Nebula
We found at this point that some of the images were trailing at 2 minutes in the East so we started to use guiding.
Slewed to NGC 1245 open cluster. [not imaged]
Slewed to NGC 1220 open cluster. [not imaged]
Slewed to NGC 1528 open cluster at 23:37
NGC 1528
Dave went off to bed whilst Bob continued.
Slewed to IC 1795 Nebula.
IC 1795 Nebula
Slewed to IC 1831 Nebula.
IC 1831 Nebula
Bob then slewed back to a number of the objects as they had trailed including, IC 1805 Heart Nebula, IC1848 Soul Nebula, IC 1260, NGC 1023 barred spiral, M34, M76, Double Cluster
Session period 19:00 – 01:18, transit start ~23:06 and end ~02:37
Before I move house, we are going to try and grab another exoplanet or two or possibly three…..we’ll see. Tonight whilst it is currently clear and due to cloud over by 1am, we will go for HAT-P-6b that is on alert from Exoclock.
Exoclock Exoplanet on Alert tonight
The transit end time is after it is due to cloud over but we may be able to get the start of the transit and some useful data to possibly half way through. So I have opened the dome, started to cool the 12″ down and slewed to a magnitude 4.29 star in the vicinity of Andromeda called HIP 116631 also known as 17 Iota Andromedae in the Flamsteed catalogue so that I can slew and centre on the object when it gets dark.
HIP 116631
I’ve now manually centred the star due to the brightness of the sky still and synced in The Sky X
Manually centredHIP 116631 in relation to HAT-P-6b
I’m now waiting for a bit more darkness to perform the first focus run.
At 20:31 I performed a focus run on the mag 4.29 star with the red filter and got position 63007 @ HFR 5.2 and temperature at the focuser of 17.28℃.
Focus run on red filter
I have performed another solve and sync as I had left the scope running for a while without guiding and the star had moved slightly.
Solve and Sync on target
I have now taken a quick 20 second exposure of the target to confirm it was the right star as per the star chart from the Exoclock website and it was.
20s exposure of HAT-P-6b
I have started guiding on a nearby star with PHD2.
Guiding
HAT-P-6b rising from the East as can be seen in TSX.
HAT-P-6b rising in the East
So here is a 2 minute exposure of the target. I tried 60 second but given I am running Gain 10 Offset 10 the maximum pixel count for the centre of the star was 1,648 out of 65k. So a 2 minute exposure produces 9,488 which is still low but I will continue on the low side for now. 1 hour before the transit is in about 45 minutes so I will wait then start gathering data.
2 minute exposure of HAT-P-6b
So we’ve started and set to run for 5.5 hours, this means a a meridian flip in 4 hours time so I will need to stay up until 2am, perform the flip then head back to bed.
First image down
The clouds have started to roll in, however so far we have been lucky and our star and planet are just outside the bank of cloud …… but for how long?
Cloud
So it finally clouded over around 1am although the data for the past 20 minutes is suspect, so I hope we at least have the first half of the transit.
Session period 21:00 – 23:57, transit start ~21:16 and end ~00:05
Started with Lum autofocus at 21:17 but on changing to the Red filter the HFR rose to 8.5 so refocused on Red at 21:20, position 60789, HFR 3.97 at 21℃. The change in HFR was more likely the warm sky and seeing conditions.
Restarted imaging at 21:39 at new Gain 10 and Offset 10 with a 15 second exposure to get the exposure down well below the 65k max to around 35k. The target star is a magnitude +7.69 so the initial Gain 139 Offset 21 and even Gain 75 Offset 12 were too high even at 10 seconds exposure.
We started with no delay in between the exposures until the start of the transit, then decided due to the large amount of data (35GB) being collected we should put a delay in which we did of 60 seconds. In hindsight we should be placed a smaller delay period in 15-30 seconds to allow us to gather more data points for the transit period. We have emailed the ESA team to start a conversation on planning exposure/delay settings for transits.
We then finished was forced to finish before the projected transit was completed when the clouds rolled in, and took Dark, Bias and Flats frame at Gain 10, Offset 10 ready for the analysis software.
After reviewing the data and the monitoring graphs it is obvious that the less than desirable Sky Temperature showed it was not truly clear. Below is the effect of high haze and cloud passing across the sky during our observation session. It should be noted that we have not had sky with a reading <= -18℃ since mid July.
Not a truly clear sky during the transit
How much impact this has on the observation and measurements we will discuss with the Exoplanet team.
22:00 – 01:44 (GingerGeek came over and Bob was remote)
So the original plan was to perform another exoplanet observation and improve/learn from our previous experiences. However the weather did not look like it was going to be accommodating so we decided to change plans.
At first we planned to take a shot of Pluto and then go back to it later on in the month to see how far it had moved but it was low and below the the IMT3 visible horizon.
Next up was to continue imaging Messier objects for Dave’s Messier Marathon collection. We settled on M14 and had created and started an imaging sequence but again the clouds rolled in putting a stop once more to some constructive imaging.
So we then decided to track an asteroid for as long as we could before the clouds stopped us. Once Dave had loaded the asteroid database into TheSkyX we then choose one close by to the previously planned Exoplanet. The asteroid 85275 1994 LY (magnitude 14.01) was in the constellation of Ophiuchus.
We turned off PHD autoguiding and mount control in the SGPro control panel as we were going to be using mount tracking on the asteroid instead of sidereal.
Autofocus using Luminance filter – 60,389 position, HFR 5.0, Temp 24.94℃. We started at 22:46 and took a series of 30 second images until the cloud cover stopped us. Dave then used the Pixinsight blink script to stitch the resulting FITS->PNG images into a movie, then looped the short AVI, added titles and music in iMovie (best viewed full screen and in HD).
@ 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.
I opened the dome at 8:30pm and then went off to do some more work. A few calls later and it was time to come back and see if I could grab comet C/2020 F3 NEOWISE which had now moved further West and further in altitude over the past week, meaning it should be visible from the dome. Below is Arcturus as I performed a quick sync.
Arcturus
Below you can see Arcturus on The Sky X with the dome slit showing and the obstructions from the horizon also present.
TSX
Comet NEOWISE can be seen just above next doors tree.
NEOWISE
A quick peek with the camera and I could just make out the comet.
Quick peek of the comet but clouds
Clearly more clouds rolled in which is typical
More clouds!
Looking at the cameras in the dome I could see the cloud bank of cloud (picture top right)
Cloud bank approaching
Fortunately the comet could be seen at the back of the cloud bank.
45 second exposure of Comet C/2020 F3 NEOWISE
So I set about quickly taking some images before the comet disappeared behind the tree.
90 second exposure of Comet C/2020 F3 NEOWISE
The other useful thing tonight was using the monitoring GingerGeek put together. Below are a selection of shots from the website.
IMT3 Conditions
The chart below shows the light cloud cover and the sky temperature is representative of the sky clarity and relates to cloud coverage too. The scale is inverted to -18℃ is a cloudless beautifully clear night sky, which tonight was not!
IMT Conditions Summary – Fisherprice style 🙂
At least there was no rain 🙂
IMT3 Rain Radar
This image below shows the cloud bank just North West of Reading that was a problem.
IMT3 Cloud Cover
This next chart is from the data produced by the AAG CloudWatcher weather station. Note the sky temperature is nowhere near the -18℃ to be clear.
IMT3 AAG Cloudwatcher weather station
And finally the all sky cam just as I packed up showing the clouds clearing
Tonight I thought I would take some more images of M57 through the 12″ in OIII and then Ha. I first got the OIII filter focused at position 62,500 with a temperature of 22.42℃, I took 10 more images at 600 seconds.
Guiding was good even though there was high level cloud, seeing was good
Ha was then started at 00:44 after meridian flip. I spent some time looking at comet C/2020 F3 NEOWISE through 100mm binoculars with Helen, Ezri and her boyfriend Luke. Then we took some photos with the 50mm lens on the 6D.
Comet C/2020 F3 NEOWISE
I went to bed at 2am and left it running. In the morning I noticed I had 10 good images then the image moved due to guiding problems due to cloud.
GingerGeek and I decided to go after M57 the planetary nebula in Lyra. I had seen a lovely photo on Flickr with the outer Ha/OIII halo showing which resembled a splat of paint, taken with 9 x 1200 seconds Ha, 3 x 1200 seconds OIII and 9 x 600 seconds luminance. So we decided to go try. It would also add to my ongoing collection of Messier objects.
M57 in OIII
The resulting image of M57 was rather small as can be seen above. We initially set an autofocus run on Ha which came in at 67,213. We then focused on OIII at 67,178. After a few frames we noticed that the focus point had shifted ever-so, thus we refocused at 23:33 for OIII and to a position of 63,610.
The OIII focus exposure length was 20 seconds on a magnitude 4 star which completed very nicely. By the time we had gathered OIII for 9 x 600 seconds the clouds rolled in. We took Flats. GingerGeek ran the whole session remotely whilst I directed 🙂
Tonight GingerGeek came over for a bit of social distancing friendly astronomy along with a bottle of Malbec wine. The idea was to calibrate the AAG, specifically when it goes from Very Bright to Light to Dark and at those points what the SQM value is along with the Sun’s position below the horizon. The AAG needs to get to 2100 which is dark, light is 5 and very light is 0.
The first time we noticed the values starting to change on the AAG brightness when it moved from its continuous reading throughout the day was at 21:47 when the Sun was -3.45 degrees below the horizon and the SQM was 10.15.
Within seconds the AAG read 9 and was already on Light vs Very Light and the Sun was now -3.54 degrees below the horizon and the SQM read 10.28.
It took almost half an hour for the AAG to get to dark. At 22:16 the AAG finally reached 2100, the SQM was at 13.97 and Sun was at -6.52 degrees below the horizon.
GingerGeek had also developed a new server for IMT3 to visualise some of the data from the observatory. The Grafana dashboard charts below show the data along with the Sun altitude.
New IMT3 Grafana dashboard
Looking at the last 24 hours shows the effect of the light nights on the SQM. The raised values after 4am went the value should be reducing or zero is the effect of a cat or bird covering the sensor. Also worthy of note is the sky temperature which shows the effect of cloud as the SkyTemperature increases. A truly clear sky would yield a value of -18℃ or better.
Shows the entire night
We also took darks on the ASC and applied them since we had never bothered to do it before. The shot below shows the before and after effect of applying the dark/bad pixel map. The whole image looks a lot cleaner and darker, although there seems to be some negative representation going on with dark pixels.
Before and after applying darks
The setting that needed to be changed in the ASC software took GingerGeek a while to find.
ASC Setting to apply darks
During the daytime the ASC looked awful but remote the darkframe reference file and just applying the badpixel map seem to be better. Tonight’s set of images will show if this is better or not.
The only other odd thing that happened tonight was the dome closed without the safety setting it off. Not sure why yet ……
