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 ……
So for a short period of time we had settled on using AllSkyEye. Recently we noticed that the author had issued a Kerogram and stretched horizon generate of the latest image but only available in a new Pro Edition.
The Pro edition was only £20 for a 3 user license, the author gives this purchase as a donation to the charity of his choice – good man ! So now we have AllSkyEye Pro in use at the IMT2 and IMT3 domes.
A Keogram is an image composed of slices taken from images in a sequential time order.The slices (which are always taken from the same location and with the same shape) are stitched together to form an image displaying a timeline of the selected part of the image as shown below.
We still have the dark map to take to remove the hot pixels from the image but at the moment it gives us a nice view remotely before we decide to open the dome – that’s if the AAG Cloudwatcher limits agree and it thinks it’s safe to do so of course !
Bob noticed we had our local security guard aka Fluffy watching over his night’s imaging and turning to watch an ISS pass.
Slightly hazy right now but I have opened the dome up and turned the cooling fans on the 12″. Slewed to Atik, a mag 2.8 star in Perseus and aligned the scope.
So the star was almost in the centre when I slewed the scope to it, a slight tweak and now synced on it centrally. The Hitec Astro weather station reports slight haze
Gingergeek installed a new Intel Windows small form factor computer recently in replacement for the RPi so we could run the AllSkEye software and see if the loss of one of the colour channels was software or hardware. Here is tonights image, which still needs colour calibrating during the day.
I find I notice some interesting things on the All Sky Camera, which is a USB 3 ZWO ASI120MC-S CMOS camera inside a purpose built casing and clear dome. Firstly I land up with beautiful clouds rolling past. I also noticed the light pollution as I mentioned in a previous post from the bathroom window upstairs. This image is when I had the camera on the ground by the observatory as I was testing the maximum length of powered USB I could get away with before data loss caused issues.
When the light is turned off it is noticeably darker.
Sometimes I get visitors to the camera.
and sometimes I unexpectedly capture a meteor 🙂
So it transpires I can use a single 3m powered USB cable to the USB hub, I cannot use 2 x 3m powered USB as that causes data loss and hangs and I cannot use a single unpowered cable either.