Herschel Wedge First Light & Best Jupiter Yet – 30th October 2023

[Captain Scarlet]

Although it’s been four weeks since my last proper session and report, they have lately been at regular intervals - I don’t feel that I’ve somehow missed a season. There have been just enough breaks in the admittedly terrible (even the long-term locals admit it!) weather to get the odd full session in. Thankfully.

Yesterday was a bonus: two sessions in a single day.

Weeks ago, I agreed to take a Baader Herschel Wedge off @Stu’s hands. I have a couple of home-made Baader Solar Film end-pieces, but since I’ve started a local Astronomy Club here where I’m not always in 100% control of things, the very slim chance of someone else removing one whilst observing outweighs the risk in my reckoning. So when Stu’s wedge became available, I caved in pretty quickly. Those Solar-film appendages will do for my Maks when I’m on my own (Herschel Wedges are strictly non-recommended for Maks).

The wedge, I believe, uses a glass prism to reflect most of the energy away to be radiated, and the remainder passes through an ND filter and a green 540nm Solar Continuum filter to the eyepiece.

Initially I got Stu to post it normally, but for some reason Irish Customs rejected it, and after a lengthy period of “radio silence” it arrived back at Stu’s place! Grrrrrr. Ireland appears to be genuinely the worst place in the world for this sort of no-explanation postal rejection. So I asked him to post it instead to my sister-in-law in Northern Ireland, who delivered it to her mum, who handed it to her other daughter, who brought it to me yesterday! It took weeks.

Once collected from sister-in-law, knock me over with a feather: it was a lovely sunny day! I quickly set up my LZOS 105 on EQM-35 to catch the last couple of hours of the sun. I started with the Nagler 31 for 21x and immediately was struck by the tiny almost cute filigree of the detail on the various sunspot groups, one of which was big and complicated (Question: do they have designations?). It was like looking at something _extremely_ intricate in high detail from a long distance away. It begged for more magnification so in went the Delos 10 for 65x, which started to show the boiling orange-peel in places (actually, lime-peel, because all this is in green 532nm light). Amazing, and far better views than I recall with my Solar film on my Intes 150mm Mak. Next clear day I get I’ll be doing a side-by-side comparison.

Further increasing the magnification, it oddly seemed suddenly to not improve at all, disappointing. Initially I couldn’t fathom it, then I realized the problem. But I had to defocus the telescope to test the theory, as of course I couldn’t look directly at the Sun to check! The picture below shows why my views had deteriorated:

That was that for my solar session. But the forecast was for it to remain clear and low-wind all night, so having de-camped the solar rig, I put out my Stellarvue 140. At 14kg for the OTA alone, only my AZ-EQ6 would do, so into the wheelbarrow and around to the other side of the house went two 5kg counterweights, the mount-head and the Planet tripod. All set up, I placed a large umbrella over the top to shield it from unobstructed exposure to the clear sky thereby avoiding early dew, and went inside to cook le diner.

After dinner (fillet steak, yum) with the Moon and Jupiter well up, I took the scope outside and added it to the mount. All set.

My intention tonight was almost exclusively Jupiter, with perhaps a side order of Moon and Uranus. I had the BBHS mirror diagonal, and had decided to control things with the Skywatcher handset rather than the Nexus DSC I more often use. Alignment was done on Polaris and Capella at 54x using the Delos 17.3. As evident from the pic, I was having to “dodge clouds”, but mostly they were thin enough to see through.

Immediately on pointing to Jupiter, I discovered by complete accident that Io was in the midst of a Shadow Transit, and that Io and its shadow were also very close together. I guess Jupiter is getting close to Opposition. For at least an hour, I couldn’t tear my eyes from the eyepiece save for brief breaks to try to settle on the right magnification. I ended up with the Delite 3mm at 313x. I felt I could have gone even higher but my smaller/newer eyepieces live in a different case and I couldn’t be bothered to go inside.

Jupiter was more detailed than I’ve ever observed it before, with multiple bands and changes of shade, and within the main Equatorial Bands swirls lanes and spots were all visible. By a huge margin it was the best I’ve seen the planet, and I’m sure there’s still better to come. But oddly, although SkySafari showed that the GRS was on show, I could not see it, despite the clarity of the rest of the disc. It must have been because bright white Io and its black spot were “out-contrasting” it, being as they were on top of or very close to the GRS by the time I got there, maybe even following it round?

I watched Io all the way to the edge, the shadow disappearing first, then Io becoming a bulge, a nipple and finally separate and free. For the next few tens of minutes, the sight of Io and Ganymede both perfectly distinctly round discs off the main planet, and the planet with its detail, gave a properly three-dimensional impression. As I said in my brief “what did you see tonight” summary, Memorable.

I took in Uranus and had a quick look for Titania, futile though at mag 13.7 with a Full Moon nearby. Uranus was as well-defined a disc at that magnification as I can recall.

Finally on to the Moon. A few trips up and down the Terminator, closer inspection of Petavius which was spectacular and even the Rilles on the far side briefly froze into view.

And then, just as I’d decided to pack up, all-encompassing thicker cloud rolled in and light rain started to descend. Perfect timing.

Thanks for Reading, Magnus

Edited November 1, 2023 by Captain Scarlet
540nm not 532

[Epick Crom]

Fantastic report Magnus, thanks for posting. This is very timely for me as I've been researching Herschel Wedge's and am interested in buying one in the future ( after I buy a refractor)

 

Thanks for the details report!

Clear Skies

Joe

[Sunshine]

Great read! and I can't believe the journey that baton...uhhm wedge! took before finally being handed off to you, that LZOS seems like a special scope.

[Captain Scarlet]

12 hours ago, Sunshine said:

Great read! and I can't believe the journey that baton...uhhm wedge! took before finally being handed off to you, that LZOS seems like a special scope.

It is a very nice scope, I think. I haven’t really used it enough or put it through its paces, as I have with the 140. I’m enjoying getting it out more lately.

[GordonD]

Great read - thanks for posting it. Sounds like a couple of wonderful sessions.

[Mr Spock]

I've been using a Lunt 1.25" for solar so far. I've now started using the 120mm f8.3 for solar with the 10nm 1.25" Continuum (it's very sharp and detailed). I've got the Baader MkII on order - the Lunt is ok with the 100mm but I think lacking a bit of wellie for 120mm. The Baader is very expensive but worth it I think. As I don't have to work anymore I shall be spending a lot of time doing solar so it's a good investment.

[Stu]

1 hour ago, Mr Spock said:

I've been using a Lunt 1.25" for solar so far. I've now started using the 120mm f8.3 for solar with the 10nm 1.25" Continuum (it's very sharp and detailed). I've got the Baader MkII on order - the Lunt is ok with the 100mm but I think lacking a bit of wellie for 120mm. The Baader is very expensive but worth it I think. As I don't have to work anymore I shall be spending a lot of time doing solar so it's a good investment.

Even with the FC-100DC, I noticed an improvement with the CoolWedge over the Lunt 1.25”, particularly at high power on fine granulation and penumbral detail. Hope you enjoy it 👍

If ever this weather improves, I have a nice Celestron Omni XLT 120mm F8.3 which should be good for WL solar.