Saturn, Mimas, Enceladus, Tethys, Dione, Rhea, Titan, Hyperion, Iapetus and Phoebe.

[Dennis]

I managed to record the 9 brighter satellites of Saturn on 15th October, whist waiting for Mars to clear the trees along our eastern horizon.

I used the Tak Mewlon 210 F11.5 with a Televue x2.0 Powermate (4830mm) and the ZWO ASI1600MM camera. It was quite wonderful to use the ASI1600MM as a “deep sky” camera to record a series of 1 sec, 5, sec, 20 sec and 30 sec exposures to tease out the moons and then switch to Firecapture and set an ROI of 1024x768 to record an LRGB Series of SER files.

No swapping cameras, no re-alignment, no refocusing required, etc.

I processed the LRGB SER Files to produce an LRGB image of Saturn and then I blended it with the 1, 5, 20 & 30 sec exposures to reveal the 9 satellites. These longer exposure frames have been non-linear stretched, to tease out the dimmer moons, so the brightness relationship between them is not accurate.

Name Mag PA° Sep"
Mimas 13.3 248.8 18.0
Enceladus 12.1 118.6 24.8
Tethys 10.6 71.8 29.1
Dione 10.8 97.2 52.6
Rhea 10.1 138.0 39.5
Titan 8.7 272.4 167.5
Hyperion 14.6 95.0 205.7
Iapetus 11.5 179.8 59.0
Phoebe 16.9 181.5 76.5

Cheers

Dennis

[h0ughy (David)]

Awesome result, fantasic

[Tinderboxsky (Steve)]

Yes, fabulous result. Inspiring.

[multiweb (Marc)]

A real tour de force. These are even fainter than the Mars moons. Great detective work and execution.

[Tulloch (Andrew)]

Excellent work. Inspiring.

[John Hothersall]

Great work, getting those difficult moons as they are never together much. I know what you mean about large sensor area great for ROI planets and the wider setting for moons as well as wide lunar.

John.

[Dennis]

Thanks for all your comments David, Marc, Andrew & John, I appreciate them.

I am in a bit of a quandary at the moment, as 4 different astronomy applications indicate 4 differing locations of Phoebe.

I may have to visit the JPL Horizons website to obtain accurate positional data to solve these discrepancies.

My admiration for the discoverers of these faint objects has increased by leaps and bounds.

Cheers

Dennis

[IanL]

You never fail to amaze me Dennis. Just fantastic. Was that from your garden Dennis.

[Tulloch (Andrew)]

Originally Posted by Dennis

I am in a bit of a quandary at the moment, as 4 different astronomy applications indicate 4 differing locations of Phoebe.

I may have to visit the JPL Horizons website to obtain accurate positional data to solve these discrepancies.

Cheers

Dennis

Hi Dennis, inspired by your image I decided to have a crack myself at Saturn and its moons, and I'm wondering if you ever worked out where Phoebe was? I used SkySafari as a guide to image it, but Stellarium doesn't agree with SkySafari, and WinJupos doesn't seem to have it at all.

Did you find a source for its location?

Andrew

[EDIT] Actually, I think this is the best source...
https://pds-rings.seti.org/tools/viewer2_sat.html

[Dennis]

Originally Posted by Tulloch

Hi Dennis, inspired by your image I decided to have a crack myself at Saturn and its moons, and I'm wondering if you ever worked out where Phoebe was? I used SkySafari as a guide to image it, but Stellarium doesn't agree with SkySafari, and WinJupos doesn't seem to have it at all.

Did you find a source for its location?

Andrew

[EDIT] Actually, I think this is the best source...
https://pds-rings.seti.org/tools/viewer2_sat.html

Hi Andrew

Historically, I have found SkyTools (v3 and v4) to be the most accurate and reliable observation planning application for off the beaten track stuff that I have been chasing.

For the inner moons, I have found Starry Night Pro (SNP), SkyTools (ST) and The Sky X Pro (TSX)to be reasonably in agreement with each other.

I like the draw "Orbit" function in SNP7 and SNP8 so I can overlay the orbits on my composite image.

In TSX you can add and plot user-added objects based on inputting RA/DEC (careful between J2000 and Apparent epoch) and then it will display on the sky chart.

I have founf the JPL Horizons website to be the gold standard for generating ephemerides of an object.

Here are some screen prints of the various apps.

Some of the fainter stuff can be a bit challenging and I have to sometimes redo an Align and Stack of a set of images to minimise picking up a processing artefact.

I usually start off by taking a series of different exposures, e.g. 1, 5, 10, 20, 30 secs to see what each one will pick up, then I select the best range and take between 20 and 30 frames for Alignment and Stacking.

Good luck - it can be fun when the weather, seeing and equipment all cooperate.

Cheers

Dennis

[Tulloch (Andrew)]

Thanks Dennis, I was put onto Nasa's Planetary Viewer site a while ago (I forgot about it until recently), the images it produces aren't as pretty as the ones you included, but you can show up to 24 Saturnian moons (if you really want).

Here's an example of the diagram it generates for the locations I'm using from last night.

Andrew

[Dennis]

Thanks for the info and link Andrew, that is an excellent visualisation tool.

Good luck with getting the 9 moons.

Cheers

Dennis

[Dennis]

I've just completed the task adding the orbits of the satellites as Layers in PS CC based on their rendering in Starry Night Pro Plus 8.

#1 is the full FOV.
#2 is cropped to Titan and Hyperion.
#3 is a crop of the brighter inner satellites.

In my somewhat vivid imagination, it's as if I am on the Cassini Spacecraft, on approach to Saturn.

I have also attached a screen capture from SkyTools 4 Imaging which provides some useful data on the system.

Cheers

Dennis

[Troy]

Great imaging of the moons