Grafana – IMT3b Observatory

Exoplanet HD189733b (18-19/8/2020) – IMT3

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.

Exoplanet WASP-74b (30-31/7/2020) – IMT3

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.

Later on I found https://www.exoworldsspies.com/en/scheduler/ as well which will be useful in the future, especially for looking at past events.

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 :

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 !

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.

Viewing Report 22nd July 2020 – IMT3

21:28 – 23:24

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.

Below you can see Arcturus on The Sky X with the dome slit showing and the obstructions from the horizon also present.

Comet NEOWISE can be seen just above next doors tree.

A quick peek with the camera and I could just make out the comet.

Clearly more clouds rolled in which is typical

Looking at the cameras in the dome I could see the cloud bank of cloud (picture top right)

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.

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 🙂

This image below shows the cloud bank just North West of Reading that was a problem.

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.

And finally the all sky cam just as I packed up showing the clouds clearing

Darkness Testing 20th June 2020 – IMT3

20:00 – 23:48

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.

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.

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.

The setting that needed to be changed in the ASC software took GingerGeek a while to find.

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 ……