Saturn and Moons et al - Monday 2nd Oct 2023 - SVX140T

[Captain Scarlet]

Two proper sessions less than a month apart! Last was September 12th. With a clear sky forecast, apart from a band of rain due to head over around 11pm, I decided to make a night of it despite the early-rising gibbous Moon. Sctually, partly because of it, as there is a particular crater I wanted to identify and photograph if possible: the Clerke crater named after Agnes Mary Clerke. She was born in Skibbereen, my nearest town, and in her day was reputedly the most famous astronomer in the world. Also, she is the namesake for the recent storm that came through, Storm Agnes. Crater Clerke, a small 7km crater close to Apollo 17’s landing site, by coincidence was in the perfect position for observing last night.

I also wanted to do more of a concentrated session, as opposed to some of my longer “tick-off” lists of late. So it was to be Saturn and as many of Saturn’s moons as I could detect; Jupiter and any detail I’ve not been ever able to see; Neptune and Triton, if possible – it was in a good position but I was worried about how close to our Moon it was. And of course the Clerke crater. Tools for the job: my Stellarvue 140 / Baader BBHS star diagonal on AZ-EQ6, controlled by Nexus DSC. I also chose to use some of my “small eyepiece” collection, what I call my “orthoscopic lookalikes”, namely the BCO 10mm, Tak 5 and 7.5 and TOE 2.5. It was to be First Light for several of these. The comparisons were interesting, too. There was one clear winner, which will become apparent as you read.

There’s been some really heavy dew lately, it being Autumn, so once I’d set everything up in late-afternoon daylight, I covered the mount-head in a large Ikea bag, having read recently about putting a barrier between the gear and the clear sky ultra-low temperature (I’m irritated I didn’t think of that myself). It worked! Also, these days I always bring the actual OTA out just before the observing session, and use the alignment process as the cool-off period, staving off dew-formation as long as possible.

Dinner finished, I headed out shortly after 9pm. The Ikea bag had done its job, Polaris and Markab served as my alignment stars (giving my Delos 17.3 its First Light, admittedly it’s not one of my “orthos”!) and Saturn beckoned.

I put in my first observing eyepiece, a BCO 10mm (First Light), slewed to Saturn, and said “Wow”. The planet itself in all its best-ever crisp detail, the Cassini División totally obvious in direct vision (first for me), a clearly darker-coloured atmospheric band, all floating amidst myriad pinpoint planetary dots: a tableau in three-dimensions. I felt as if I could reach out and touch it all. The dots were: Titan, Dione, Rhea, Tethys, Enceladus, Mimas and Iapetus. All at just 94x with the Baader Classic Ortho 10mm. I’ve since learned that Mimas was a real catch, not least at 94x! I recall initially seeing a pair of dots, one above and one below, just off the Eastern edge of the rings, both perfectly clear, the lower one brighter than the upper. I looked them up: Tethys below and Mimas above. They reminded me of the Trapezium E and F stars, so tricky but in the right conditions, dead easy. I tried hard for Hyperion too, but it was out of reach.

I replaced my BCO 10 with my Tak LE 5, for 188x, and it was all far less satisfying. I could still make out Mimas, but only barely. Most odd. I got my Celestron Ultima 2x Barlow (First Light) and put the BCO into that, to give an equivalent 188x, and it was much better again, though not as exquisitely sharp as at half the magnification. So, in direct comparison, BCO 10 + Celestron Ultima 2x defeats the Takahashi LE 5. I put in the Tak LE 7.5, and that was better than I was expecting given the 5. I did briefly put in the Tak TOE 2.5, giving me 375x, but it was too much. And the later it got, the less I could detect the three mag 10 moons, with Mimas disappearing entirely.

Anyway, by now Jupiter seemed not too low, but in fact it was. Some nice detail was on show, much more than simply the main Equatorial Bands, but there was still significant CA. I moved on to Neptune to see if Triton was available. It wasn’t. At mag 13.6, given that I’d seen mag 13 Mimas I thought it might be possible but it was that much closer to the Moon, which itself was that much higher. Another day for Triton.

From here I swapped between Saturn and Jupiter, spending much time on each, and as he got higher, Jupiter got better and better with plenty of detail on view. Mostly I used the BCO 10/Barlow combination. Saturn, in contrast, got worse and worse as some serious-looking cloud – brief rain had been forecast – started impinging from the West. Eventually I had to take a literal “rain check” and wait:

Sky washed clear, I moved on to the Moon. I found crater Clerke quite quickly. At least I think I did. I still need to check an authoritative reference against the rubbish phone-pics I took (edit - I just checked, all good, I think).

All in all an enjoyable night. Nexus DSC behaved perfectly, and First Light happened for at least three of my eyepieces. Very happy in hindsight with Mimas. I look forward to having another go at Triton, and two other ambitious targets, perhaps too far-fetched: Hyperion, another of Saturn’s moons; and Amalthea (Jupiter’s fifth-in-line) which at mag 14.5 might _just_ be possible on a very dark night, likely with my 12” rather than the 140 but who knows? I’ve reached 14.7 in this scope before. And I discovered what an absolute star the BCO 10 is. Are all the BCOs that good?

Thanks for Reading, Magnus

 

Edited October 3, 2023 by Captain Scarlet

[John]

Great report Magnus - wish I had one that I could make tonight !

Triton is well worth looking out for - I have seen it a couple of times with my 130mm refractor. I'm hoping to get it with my 120 this season. 

If you can break mag 14 with your 140 then a the brightest of Uranus's moons (Titania and Oberon I think) might be "on" when they are well placed 🙂

 

[josefk]

Hardy stuff with the brolly out 🙂 i hope not to resort to those measures but feel like this planetary season is passing me by with the weather system that seems to be stuck here so you never know. ...and food for thought on the 10mm BCO - interesting.

[CraigT82]

Nice report Magnus, the 10mm BCO is a real peach, even at twice the price. Great deep sky eyepiece too. 

[Stu1smartcookie]

Magnus , your session reports are always a great read . Have to say it makes a change from constantly reading about astrophotography and its technicalities on SGL . 

Long Live Visual ! 

[badhex]

On 03/10/2023 at 22:53, Captain Scarlet said:

Two proper sessions less than a month apart! Last was September 12th. With a clear sky forecast, apart from a band of rain due to head over around 11pm, I decided to make a night of it despite the early-rising gibbous Moon. Sctually, partly because of it, as there is a particular crater I wanted to identify and photograph if possible: the Clerke crater named after Agnes Mary Clerke. She was born in Skibbereen, my nearest town, and in her day was reputedly the most famous astronomer in the world. Also, she is the namesake for the recent storm that came through, Storm Agnes. Crater Clerke, a small 7km crater close to Apollo 17’s landing site, by coincidence was in the perfect position for observing last night.

I also wanted to do more of a concentrated session, as opposed to some of my longer “tick-off” lists of late. So it was to be Saturn and as many of Saturn’s moons as I could detect; Jupiter and any detail I’ve not been ever able to see; Neptune and Triton, if possible – it was in a good position but I was worried about how close to our Moon it was. And of course the Clerke crater. Tools for the job: my Stellarvue 140 / Baader BBHS star diagonal on AZ-EQ6, controlled by Nexus DSC. I also chose to use some of my “small eyepiece” collection, what I call my “orthoscopic lookalikes”, namely the BCO 10mm, Tak 5 and 7.5 and TOE 2.5. It was to be First Light for several of these. The comparisons were interesting, too. There was one clear winner, which will become apparent as you read.

There’s been some really heavy dew lately, it being Autumn, so once I’d set everything up in late-afternoon daylight, I covered the mount-head in a large Ikea bag, having read recently about putting a barrier between the gear and the clear sky ultra-low temperature (I’m irritated I didn’t think of that myself). It worked! Also, these days I always bring the actual OTA out just before the observing session, and use the alignment process as the cool-off period, staving off dew-formation as long as possible.

Dinner finished, I headed out shortly after 9pm. The Ikea bag had done its job, Polaris and Markab served as my alignment stars (giving my Delos 17.3 its First Light, admittedly it’s not one of my “orthos”!) and Saturn beckoned.

I put in my first observing eyepiece, a BCO 10mm (First Light), slewed to Saturn, and said “Wow”. The planet itself in all its best-ever crisp detail, the Cassini División totally obvious in direct vision (first for me), a clearly darker-coloured atmospheric band, all floating amidst myriad pinpoint planetary dots: a tableau in three-dimensions. I felt as if I could reach out and touch it all. The dots were: Titan, Dione, Rhea, Tethys, Enceladus, Mimas and Iapetus. All at just 94x with the Baader Classic Ortho 10mm. I’ve since learned that Mimas was a real catch, not least at 94x! I recall initially seeing a pair of dots, one above and one below, just off the Eastern edge of the rings, both perfectly clear, the lower one brighter than the upper. I looked them up: Tethys below and Mimas above. They reminded me of the Trapezium E and F stars, so tricky but in the right conditions, dead easy. I tried hard for Hyperion too, but it was out of reach.

I replaced my BCO 10 with my Tak LE 5, for 188x, and it was all far less satisfying. I could still make out Mimas, but only barely. Most odd. I got my Celestron Ultima 2x Barlow (First Light) and put the BCO into that, to give an equivalent 188x, and it was much better again, though not as exquisitely sharp as at half the magnification. So, in direct comparison, BCO 10 + Celestron Ultima 2x defeats the Takahashi LE 5. I put in the Tak LE 7.5, and that was better than I was expecting given the 5. I did briefly put in the Tak TOE 2.5, giving me 375x, but it was too much. And the later it got, the less I could detect the three mag 10 moons, with Mimas disappearing entirely.

Anyway, by now Jupiter seemed not too low, but in fact it was. Some nice detail was on show, much more than simply the main Equatorial Bands, but there was still significant CA. I moved on to Neptune to see if Triton was available. It wasn’t. At mag 13.6, given that I’d seen mag 13 Mimas I thought it might be possible but it was that much closer to the Moon, which itself was that much higher. Another day for Triton.

From here I swapped between Saturn and Jupiter, spending much time on each, and as he got higher, Jupiter got better and better with plenty of detail on view. Mostly I used the BCO 10/Barlow combination. Saturn, in contrast, got worse and worse as some serious-looking cloud – brief rain had been forecast – started impinging from the West. Eventually I had to take a literal “rain check” and wait:

Sky washed clear, I moved on to the Moon. I found crater Clerke quite quickly. At least I think I did. I still need to check an authoritative reference against the rubbish phone-pics I took (edit - I just checked, all good, I think).

All in all an enjoyable night. Nexus DSC behaved perfectly, and First Light happened for at least three of my eyepieces. Very happy in hindsight with Mimas. I look forward to having another go at Triton, and two other ambitious targets, perhaps too far-fetched: Hyperion, another of Saturn’s moons; and Amalthea (Jupiter’s fifth-in-line) which at mag 14.5 might _just_ be possible on a very dark night, likely with my 12” rather than the 140 but who knows? I’ve reached 14.7 in this scope before. And I discovered what an absolute star the BCO 10 is. Are all the BCOs that good?

Thanks for Reading, Magnus

 

Fantastic report Magnus, a real pleasure to read and a reminder that those great sessions do exist between the endless clouds! Whilst reading I had flashbacks of a session of my own from a year or two ago observing Saturn and Jupiter, first observations of a couple of Saturn's moons (though not Mimas nor Enceladus) and testing out the BCO 10mm plus Barlow combo - a fantastic planetary EP. Going to have to track that down to read now 🙂

If you get your hands on a decent 2.5x Barlow at any point it is also excellent as a 4mm equivalent as well. 

Looking forward to your next report, and fingers crossed for the rest of the moons on your wishlist!