The 4 Galilean satellites of Jupiter, Amalthea and 8 of the outer, irregular satellit

[Dennis]

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

[Saturnine (Jeff)]

You certainly took on an interesting challenge with those moons Dennis, have done well to capture and recognise them .

[Dennis]

Originally Posted by Saturnine

You certainly took on an interesting challenge with those moons Dennis, have done well to capture and recognise them .

Thanks Jeff, SkyTools 4 which can plot these satellites and place the OTA on them made it so much fun.

I'm having 2nd thought s about Leda after I plotted its path in The Sky X Pro using JPL data but I still think I have it on a set of frames I took earlier.

You can never be too sure with these faint suckers.

Cheers

Dennis

[Dave882 (David)]

Really interesting Dennis. Great project!

[Dennis]

Thanks David, the research and data gathering before setting up are almost as good fun as being able to record these fainter bodies.

Dennis

[Dennis]

I did not feel super confident 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 x 60 sec 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 in The Sky X Pro, there is a very good fit to the recorded trail.

I also identified some fainter field stars using 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.

Dennis