Thoughts from Starlight Cascade

Another night of imaging with the Meade 102mm SC on the Meade LXD55 equatorial mount in the Serenity Observatory.  Started with realigning by hand the OTA on the dovetail, as it had slipped.  Need to take it off and tighten that single point of attachment sometime, but not last night and not just before a session.

Powered up the mount, told it to do a two star alignment, using Arcturus and Mizar.  Used the new two holer Hartmann mask to focus on Mizar and low and behold, resolved the double star and it was quite sharp.  The Hartmann mask came off  and told it to go to Jupiter, and it did get  close, within the 1/2 degree of the innermost Telrad circle.  Found it.  Added the dew shield and started imaging runs, two 30sec first then 180second runs.  The seeing appeared average but the transparency poor.  I was not happy with the ongoing image, so after 3 runs, fiddled with the focus.  It got worse 🙁

While processing the images I noticed the Great Red Spot… on the wrong hemisphere.  I then remembered that for some reason the equatorially mounted scope, after the 2 star align, went to Jupiter and was upside down from its normal orientation.  Wonder why that happened?  So in Irfanview, I rotated the image 180 degrees and all was good again.

But on the other hand, updated images of the scope and observatory are annotating well.  Still no successful imaging of Mars yet…

Below is an animated compilation of all 6 or 7 imaging runs:

Todo: resecure the OTA to the Dovetail, lower the tripod slightly as its new height is touching the closed roof.

Friday evening was the first nice clear skies in over a week. So we were out observing and imaging. by 9pm the temp had dropped to 6.6C, below the predicted low of +7C. In the end it went down to +0.7C just before sunrise.
Weather forecasting is not even close!

So.. this is Jupiter at azimuth 178, almost due south, as good as it will get this year, at 2020 sept 12, 00:48 UTC or 2020 sept 11 20:48 EDT. It took 30 minutes to find Jupiter in the Meade 102mmSC on the Meade LSX55 mount. I ended up increasing the height of the tripod so I could go around back outside of the observatory (4’x4′) and look through the telrad.
That did not work out as the mount tripod leg started to slip.
After securing that again, I went inside the observatory and limbo’d under the counterweight arm to get in behind the scope to peer through the telrad.

Finally nailed it, used a two hole Hartmann mask to attempt a good focus, but it looked pretty poor all in all.
Note to self: Make another Hartmann mask. This one is too big and the two holes impinge on both the secondary mirror and the outside of the corrector plate.

With Firecapture and the ZWO ASI 290MC camera, I took a 30 second imaging run with image brightness around 70%, giving a 66ms exposure, with no autoalignin gand a region of interest of around 600×600 pixels.
Then I took another with autoalign turned on. This helps give me a record of the seeing that night.
Things looked good. The mount was not tracking well so I was manually guiding corrections every 30 seconds or so.
Then I moved up to a 120sec run, correcting guiding again about every 30 seconds.
The 120 sec was the limit I used on the older 20cm meade lx200gps.. but then I realized that was because of its higher resolution and the max time before a surface feature moved from one pixel to the next.
On this smaller scope, I should be able to do longer imaging runs without that happening.
So I bumped it up to 180 seconds, more frames per run allowing for better stacking.

In the event the dew fell, the corrector plate fogged over and I called it a night after only 11 runs in total.
Note to self – build a small dew shield.
I am toying with the idea of building a slightly larger imaging observatory. 4’x4′ gross is just a little too small.

So.. without further , here is the best of Jupiter last night, serendipitously capturing a shadow transit of the satellite Europa and Europa itself on the upper right of Jupiter.

And an animated .gif of the 11 images of the night

Saturn is another favourite target and this again was the first imaging run in weeks, possibly since opposition.

With very heavy processing the Cassini division just comes out, but there is also a lot of fluffy noise around the rings. Being only a 30 second exposure with only 159 frames and using only 20% of those, it is no wonder there is so much noise.

And since there were only two imaging runs of Saturn before the mount decided to meridian flip yet again, and I stopped for the night, it is almost not worth posting the animated .gif here:

Greetings!
After almost a month of being too busy in the gardens/cloudy nights, here is the best image from last night (Sunday 2020 Sept 06) in the evening.

Most of the image specs are in the actual image, annotated with the linux based ImageMagick utilities. I have been trying to figure out the best way to annotate text onto an image, especially with different scopes, barlows, fratios, etc.
I think I have finally hit upon a method. create a text file with all of the relevant info and use it. The altitude, diameter and magnitude would not change much in the space of an hours worth of imaging. The Central Meridian will change however… still working on that one.

UT Time
Altitude=22 deg Diameter=43.5″ Magnitude -2.5
CMI=148.9° CMII=84.1° CMIII=175.3°
Meade 102mm Schmidt-Cass f25 ZWO ASI290MC frames=best 20% of 1250
Kevin Kell SCGO-Serenity Observatory Yarker Ontario Canada

and also adding in the filename itself, which contains the UTC date and time along with exposure, camera, autostakkert alignment points, drizzle factor, and wavelet settings.

At the top left is an image of the actual telescope used
At the top center is the planetary image orientation (I am a north is up kinda fellow)
At the top right is the observatory used

Line one confirms UT time
Line two gives the approx altitude of Jupiter above the horizon along with its apparent diameter and magnitude (from stellarium)
Line three comes from firecapture text file and is the Jupiter Centrlal Meridian coordinates
Line four is the telescope, aperture, fratio (native F10 but using x2.5 barlow=f25), camera and the percentage of best frames out of the total number of frames taken.
Line five is the copywrite information about myself, which observatory these were based out of and the geographic location.

Lastly I create animations out of all of the images of the night and that is shown below (click on the image to see the animated .gif).

The linux bash script looks like this:
#!/bin/bash
#2020april28
#assumed image size is 750×750 and is .png
#2020aug17 change to serenity meade 102mm SC
echo starting annotation
echo removing spaces in filenames
for f in *\ *; do mv “$f” “${f// /_}”; done
echo change filename case to lower case
for file in * ; do lower=$(echo $file | tr A-Z a-z) && [[ $lower != $file ]] && mv $file $lower ;done
mkdir annotated
for i in *.png
do
echo start annotation on $i
echo add scope100 icon filename to a
composite -geometry +1+5 scope100.jpg $i a.png
echo add north icon a to b
composite -geometry +350+5 northisup.jpg a.png b.png
echo add obs100 icon b to c
composite -geometry +650+5 obs100.jpg b.png c.png
echo add text c to d
convert c.png -pointsize 14 -fill white -annotate +9+670 @annotation.txt d.png
echo add filename
convert -font helvetica -fill white -pointsize 14 \
-draw “text 10,650 ‘$i’ ” \
d.png $i-annotated.png
done
rm a.png
rm b.png
rm c.png
rm d.png
convert -delay 20 *annotated.png jupiter.gif
convert *annotated.png jupiter.mpg
mv *annotated.png annotated/

>> Jupiter satellite events from project pluto
>> I = IO
> II = EUROPA
> III = GANYMEDE
> UTC-4 hours=EDT
>
> II : Tra start: 14 Aug 2020 11:36
> II : Sha start: 14 Aug 2020 13:03
> II : Tra end : 14 Aug 2020 14:23
> II : Sha end : 14 Aug 2020 15:52
> III: Tra start: 14 Aug 2020 23:30
>
> 22:30 EDT
> III: Sha start: 15 Aug 2020 2:30
> III: Tra end : 15 Aug 2020 2:51
> I : Tra start: 15 Aug 2020 3:23
> 00:08 EDT
> I : Sha start: 15 Aug 2020 4:08
> I : Tra end : 15 Aug 2020 5:40
> III: Sha end : 15 Aug 2020 5:54
> 01:54 EDT

This is an image of the shadow of the moon Ganymede (top left) and you can barely make out the moon itself leaving transit on the limb (right a little above middle).

I successfully used the two holer (hartman mask). I focused by eye first on Arcturus then used the mask and did see two distinct images, adjusted the focus until it was a good as possible, then removed the mask and slewed to Jupiter. I had tried using the mask on Jupiter but as a nonpoint source, it did not work at all.

Tracking was problematic and I had to manually guide the expos

Imaging Jupiter last night during the Perseids, waiting for midnight to come for hopefully better and more meteor displays.

These are before and after Registax v6 wavelet processing, to show the power behind wavelets, and the fact that I still do not have what I consider ideal settings 🙁

Seeing was average

Transparency was good but got worse

Sky Quality Meter reading: 21.48 mag/arcsec^2

Meade LXD55 mount tracking below average

Meade 102mm SC F10 FL=1000mm plus a x1.5x barlow, effective FL=1500mm
No dew shield or dew heater on the Meade 102.
North is down (I normally do up)
Thesee are the best 50% of the images.

	Start of run 02:48UTC	End of run 03:14 UTC
Before wavelets
After wavelets