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4 Galilean moons, Amalthea and 8 of the outer satellites of Jupiter.
#1
I used SkyTools Imaging 4 (ST4) to plan for and enjoy a very successful imaging session, recording the classical 4 Galilean satellites of Jupiter, the fainter inner body Amalthea and 8 of the fainter outer, irregular satellites.
 
Celestron C9.25 Edge HD F10 at prime focus (2350mm).
ASI2600MM Pro (Bin 2x2) for the outer, fainter moons. 60 sec exposures, Gain=0, Offset=15. (The Sky X Pro Camera Add On).
Player One Saturn SQR (Bin 1x1) for the 4 Galilean satellites and Amalthea. (SharpCap).
Bortle 7 skies.
 
I used SkyTools Imaging 4 (ST4) to locate and GoTo all the satellites, other than Leda, whose data I obtained from the JPL Horizons website. ST4 provided the following information for my location in Brisbane, set for the mid-time of my session.
 
Name                  Mag      PA°        Sep"
Io                         4.8         247.4    95.1
Europa                5.1         75.8       156.8
Ganymede         4.4         226.8    53.6
Callisto                5.4         281.0    72.3
Amalthea           13.9       230.8    9.5
Himalia               14.6       223.6    3538.0
Elara                    16.6       98.7       1682.8
Pasiphae            16.8       277.4    12164.8
Sinope                18.1       273.4    2576.9
Lysithea              18.2       168.9    1982.4
Carme                 17.8       236.3    8051.9
Ananke               18.7       76.2       7649.4
 
Sinope was the most affected by the spill over of unwanted glare from the Jovian disc, so I had to place it towards the edge to lessen the impact. The whole project was made so easy through being able to obtain all the bodies data (apart from Leda) in ST4 and use ST4 to slew to each body in turn. I grabbed between 10 and 15 frames of 60 secs each which easily recorded these brighter satellites.
 
The positional data for Leda was obtained from the JPL Horizons website and I slewed to the RA and DEC coordinates to locate it. I grabbed 56x60 sec frames for the much fainter Leda. The recorded position is a good candidate when compared to the JPL position but to be certain, I would probably have to image it again to see if it has moved.
 
2023-Oct-20 15:00UT.
RA=02 38 05.41 DEC=+13 51 51.0.
Magnitude 20.068.
01 27 25 AEST
 
******** ASTROMETRIC SOLUTION RESULTS ********
Scale: 0.6460 arcseconds/pixel
Size (pixels): 3124 x 2088
Angular Size: 0° 33' 38" x 0° 22' 29"
Position Angle: 0° 49' from north through east
Mirror Image: No
RMS: 0.68 (X: 0.56 Y: 0.38)
Number of Stars Used in Solution: 102 (100%)
FWHM: 3.29 pixels, 2.13 arcseconds
**********************************************
 
I used Player One Saturn SQR (Bin 1x1) for the Jovian disc and Amalthea, with the 4 Galilean satellites of Europa, Callisto, Io and Ganymede as it had a higher framerate of 42 fps.
 
The 4-panel frames are full res crops where I have overlaid the text from ST4 over the BYW image, as a colour Layer in PS CC, to identify the satellites.
 
Dennis

   

   

   

   

Here are a few screen shots of SkyTools 4 Imaging that proved invaluable in tracking down these faint objects and determing the West Elongation of Amalthea.

Dennis

   

   

I have zoomed in for this scree capture, so some of the outer satellites lie outside the field of view.
   
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  • PMSchu
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#2
Wow Dennis that is extremely impressive. I mean, wow.

I didn't include Leda because I didn't see any evidence that it had ever been imaged by any amateur. But it has now! So I will add it. Thank you for posting this here.
Clear skies,
Greg
Head Dude at Skyhound
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  • Dennis
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#3
Thanks Greg, ST4 was the star performer and enabler for this imaging session and really set it up for success.

I may have to do some more research on my Leda candidate, as although I have an object in the plotted position, with these fainter objects you are never quite sure if you have picked up a fainter field star or some processing artefact.

I tried again for Leda last night to see if I could plot its movement over the 2 sessions, but the clouds rolled in before Jupiter cleared the tree line.

I must say it really was quite thrilling to have ST4 plot these more esoteric bodies so accurately – thank you.

Dennis
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#4
I did not feel confident enough that I had recorded the faint outer satellite Leda on the images I took on my second run, posted above, so I went back to Run 01 and processed the 27 frames using PixInsight.

Pleasingly, the results were much more conclusive, and I now feel more confident that I managed to record the faint trail of Leda, a magnitude 20.068 satellite of Jupiter.

I obtained the positional data from the JPL Horizons website and plotted the calculated positions for the start/end times of the 27 frames I captured, and the fit was excellent.

Run 01
Start/End UT
2023-Oct-20 14:38          RA: 02 38 05.78 DEC: +13 51 53.4
2023-Oct-20 15:05          RA: 02 38 05.32 DEC: +13 51 50.5

27 frames at 60 secs
Brisbane QLD.
 
21st October 2023 12:38am to 01:05am AEST (UT+10)

I plotted the JPL data and when I overlay the results, there is a very good fit to the recorded trail. I also identified a couple of faint field stars, at mag. 20.01 and 20.08 to give me some confidence that I was reaching these fainter levels.

Dennis

   

   

   
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#5
Congrats!
Clear skies,
Greg
Head Dude at Skyhound
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  • Dennis
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#6
Wow, Dennis! That's some fantastic sensitivity from a 9.25" aperture with a 60 second exposure.

Nicely done.

Phil S.
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  • Dennis
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#7
Finally, I decided to check some of the fainter field stars against the GAIA DATA RELEASE 2 (GAIA DR2) Catalogue and annotated the attached image.

This has given me more confidence that I now have a good candidate for Leda. Smile

Dennis

   
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#8
No doubt Dennis. Fantastic job.
Clear skies,
Greg
Head Dude at Skyhound
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#9
Dennis,

Have you submitted your image to the astometry.net website to see if they can identify Leda in your image?

Phil S.
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#10
Thanks for the suggestion Phil, I have used Astrometry.net previously but I am not sure it can detect planetary moons?

Anyhow, I uploaded the cropped 1600x1600 pixel region and overlaid the results (red circles) on the Leda image (my yellow circle and label).

I browsed the site/settings to see if there was an option to "activate" solar system objects, but could not find one.

Dennis

   
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