Captain Scarlet

2 hours ago, Deadlake said:

I’ve not taken mine apart but interesting to see what is inside.

For your local meet what mount did you use, the 105 F6.25 is quite heavy when outfitted with a FT 3545, mines 8 kg. Too heavy for the ScopeTech I have and a little over mounted on the AZ100.

Thanks

Yes that weight sounds about right, it’s certainly no lightweight. I also had an APM 8x50 finder attached. It was on an EQM-35, without counterweight (which I forgot when loading the car). It was fine, actually.

58 minutes ago, Mutley said:

Bit off topic but as you're here @Captain Scarlet, is that a Berlebach Planet? Does it have a removable azimuth pin - just wondering if I got a Planet with an EQ6 fitting, would it also do for an AZ-100,?

 

 

Yes it is a Planet, and I’ve just checked the az pin is removable. I believe @Stu has an AZ100 on a Planet.

I quite happily mount my 12” Newtonian on an AZ-EQ6 in alt-az mode. Although mine is now lighter than it used to be at around 21kg, my much heavier 300p came in at 27kg with finders eyepiece etc, and that was ok too, for visual only I should add. The Rowan AZ100 would be fine too I think.

Magnus 

Last Thursday I brought my LZOS 105/650 to our local Astro meet, and when it came to mounting the scope onto the saddle, I had the devil of a job trying to extend the dewshield. It eventually succumbed to my fingertips but it was a worry.

Today I took it apart to see what was wrong. It turns out the felt lining the inside ring of one end securing the dewshield had detached itself from the adhesive. The adhesive itself was still more or less on the metal ring, effectively gluing the dewshield in place!

I removed the loose felt/flock, cleaned everything up and re-attached some new flock/felt. It now slides as it should.

It was interesting to see how it all goes together and the Cell as a separate unit.

Cheers, Magnus

2 hours ago, JeremyS said:

That’s a very helpful guide!

This overview of observing Jupiter visually from the BAA Jupiter section is a nice summary: https://britastro.org/2023/visual-observation-of-jupiter

 

Very interesting and useful too. Thanks

M

As to what actually happened to fog up your primary: when, after an observing session say, you bring a cold scope or mirror into the warm house, the glass immediately fogs up of course. Here it’s the same but in different circumstance. By heating the secondary, you’ve added heat to the air inside your tube. So you’ve effectively brought warm somewhat humid air to a cold mirror and in just the same way the water vapor condenses onto your cold mirror.

Cheers, Magnus

A few days ago @Chandra posted a very useful reference chart of the object-types for features of Jupiter, which I’ve taken the liberty of re-pasting here:

I could guess all the abbreviations except SDER, which it turns out stands for something like Spot Dark [within] Extended Region. In finding that out, I came across this below, which is also useful, especially page 13.

http://www.jupos.org/etc/JuposProjDoc_English.pdf

It’s at a non-secure link (i.e. not https) so might not always be available. Key screengrab here:

Page 16 also shows names and abbreviations for all the bands.

Cheers, Magnus

I suggest Edison for John’s ED120 🙂

5 hours ago, Nikolai De Silva said:

Was the 130p good? Because I have a Starquest 130p, haven't used long yet. Need to know just how it is. For what it is good for?

Hoping for a response😁

Nikolai.

It is a good scope, all the more so because on my advice he upgraded his eyepieces to BST Starguiders. The mount he has with it is not good though, especially as he has wrestled it into as close to alt-az mode as he can by tilting the RA axis as far over as it will go. With the counterweights consequently tangled up in the tripod, he was changing azimuth for different targets by picking up the tripod and re-placing it! There was only so far I could go in giving there-and-then advice without becoming a bore. Herewith the perils of a beginner being given an eq mount. Luckily his enthusiasm remains undiminished and for now I’ll lend him my stellarvue M-2 mount, far more intuitive.

Others were in fact impressed by the views of Jupiter through his scope. I was even more impressed when, after everyone else had been driven away by the cold, we discovered he had had his lens-cap aperture-mask on the whole time 🤣🤣. Again luckily, he saw the funny side to it. His wife, who was there with us for a time, apparently still hasn’t stopped laughing.

Anyway, yes the scope is remarkably good, but it needs decent eyepieces and a more sturdy mount than the eq-2.

Magnus

Tonight was Astronomy night for our fledging astro group. I took two scopes, my LZOS 105 on eqm-35, and my Skymax180 on skytee2. One other member brought his own scope, a 130p on eq3. About 8 turned up, but didn’t last long once outside as it was a bitter -2 and a 15mph unsheltered north-easterly. We all got to see Jupiter and Saturn through all 3 scopes though.

It was the first time I’ve had the Skymax 180 out for more than a year, perhaps even two. But tonight on Jupiter it was tantalizingly very very good indeed, GRS clearly on show with its change of SEB shade fore and aft, sitting within what I too saw as a pale surrounding ring; but I could only sit and look for brief moments before guiding the rest of the group. Lovely scope, I’ve missed it.

I had my best-ever views of Jupiter a couple of nights ago with my 8” f/4.4. Mirror was filthy too. The fact you can get a used SW200p for £150 or so is amazing. It really is the Goldilocks scope both for its abilities and its £ outlay.

I was observing Jupiter last night with my 8" newtonian, and also particularly noticed that shade change either side of the GRS. Also that the coloue of the GRS was the best I've seen it. I thought it would have been a good evening for me to start sketching, there was plenty to sketch.

Thanks for the drawing, Magnus

Just in from a great 2-3 hours on Jupiter and probably 10 minutes on Uranus. My 8” Newtonian, Delos 6 for 167x giving views that easily surpassed my previous best-ever a few weeks ago with the SV140.

Wonderful intricate detail and a GRS that was really and obviously Red. Suddenly curtailed as Jupiter transited a house and all was mush.

Magnus

I’ve replaced the main saddle on mine with an ADM one, so the original saddle is spare and unused. I’ll happily dig a spring out and send it to you…

Magnus

It’s describing the frequency in meteors per second as opposed to a more usual meteors per hour. My God it could be the event of the decade for those with dark skies and clear nights!

@markse68’s profile backdrop photo comes to mind…

Magnus

The second highest-ever energy particle has been detected apparently. The Guardian article below says

When ultra-high-energy cosmic rays hit Earth’s atmosphere, they initiate a cascade of secondary particles and electromagnetic radiation in what is known as an extensive air shower.

Some charged particles in the air shower travel faster than the speed of light, producing a type of electromagnetic radiation that can be detected by specialised instruments.

… what is meant by that second paragraph? “Faster than light”? A case of journalistic misunderstanding? @andrew s? @vlaiv?

https://phys.org/news/2023-11-telescope-array-second-highest-energy-cosmic-ray.html
 

https://www.theguardian.com/science/2023/nov/24/amaterasu-extremely-high-energy-particle-detected-falling-to-earth?CMP=Share_iOSApp_Other
 

Magnus

Sky was unexpectedly clear so I set up aiming to see Jupiter with the 8”, having had increasingly good views through the 105 and the 140 in recent weeks. In the event I got about 5 seconds of the Moon as a pre-align, and that was it, total cloud, suddenly and completely.

I’m sure they’ve done their sums but that wedge looks disproportionally small for the monster atop it.

34 minutes ago, Alan White said:

Dear All, I cannot help myself, I have slipped off the non buying mode and bought a pair of DeLites from @The60mmKid, Siddhesh.

Very plesed with them too, had the same before so knew what to expect.

Oh this is a slippery slope with the @FLO clearance items on offer!

How funny they went together - I did the same and took the other 7 & 13. Makes a nice cascade for me to partner up with my 18.2 and 3. Though it’s going be a bit longer before mine actually arrive.

Magnus

Another long journey but this finally arrived. A correct-image adapter for Newtonians that Vixen used to do. It appeared on ENS and I was curious. Telescopic sights for rifles have them built in.

SW used also to supply very cheap such adapters with their scopes, but this is supposedly high quality.

23 hours ago, Zermelo said:

Yes, perhaps I should have said "settle up" rather than "settle down".

In my experience the phrase “settle up” causes an expectation of payment. The phrase “settle down” usually results in an argument 😁.

22 hours ago, pete_n_pugs said:

… Is it worth pursuing - or should I just make sure the secondary and primary are aligned?

Yes to the second part of that question. The _position_ of the secondary only affects illumination levels, it’s not really collimation proper, i.e. “alignment of the optical elements”, which are eyepiece and primary mirror. With a slightly misplaced secondary but otherwise collimated focus-tube and primary, you will still get views as aberration-free as they can possibly be. You will not notice the illumination difference visually with a secondary slightly out of position.

Ideally of course you’d like that secondary to be symmetrically straddling the primary light cone, but more important, by far, is to align the focus-tube axis with the primary mirror axis.

Magnus

A very quick session with the 15x56s after some cloud and showers briefly cleared at bedtime. M81/82 nice. M51 and M101 not detected despite much trying, too low in thin haze over Skibbereen. M1 Crab was visible though, as was M33. M42 and M31 both naked eye. Jupiter and Moons. Feet got cold so back in.

Magnus

Another thought is the side-grubscrews in the mirror cell, restraining the mirror laterally. They also need to be made to contact, then 1/8 turn reversed. With my old 300p I once cleaned the mirror then tightened up those grubs, but not by much. That night my brother in law asked “why are all the stars triangular?”. Mirror-clips and those grubs have a much greater effect than you’d think .

Cheers, good luck with the diagnosis, Magnus

I finally achieved B33/HH a couple of years ago, and I attribute it to the following combination of factors: dark site (21.8); perfect transparency (any thin cloud is enough to extinguish it); no Moon; no alcohol (important - optic nerve is affected. Learned that from @jetstream); 12” of aperture; full dark adaption; four years experience/learning of how to try to see really faint things. It was possibly my ~5th attempt to see it and I literally danced with joy when I’d convinced myself I’d detected it.

Magnus