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Abell 1656 - Coma Galaxy Cluster and Quasar Hunt With all the poor weather in the UK so far I had a rare clear night on 9th April 2024 and a New Moon as well. Here is Abell 1656 in Coma Berenices. There are some 100 quasars (green label), a planetary nebula (red label) and too many PGC galaxies to count in this image. Nice to see that I managed to capture some bright pixels for the Quasars as well. Equipment & Data William Optics Z103 refractor. ZWO ASI294mc Pro with Chroma Lum filter. Sky-Watcher EQR6-Pro mount. 161 x 120" subs, Gain 121, Offset 30, Sensor temp -10 c, Bin 1x1

To say this is rare is an understatement , this is up there with the "Human rights in the Aztec Empire" or "The Atlanteean Farmer Almanach" : a book about Romanian star and sky lore AND in english AND available on Amazon ! And lo and behold , also available as eBook ! Not affiliated with the authors , not involved with it's publication , but if something deserve the "hen's teeth" designation this is it : Romanian Star & Sky Lore: Otescu, Ion, Gheorghe, Andrei Dorian, McBeath, Alastair: 9786069569139: Amazon.com: Books

This was my point. The galaxies do move apart from each other without the need for proper motion. It seems to me that there are two ways of looking at the 'motion' imparted by the Hubble flow. We can take the point of view of an observer on a single galaxy and see radial recession on the part of the others, or we can conceive of galaxies within a universal expansion. We cannot observe this conception because an observer, of course, is pinned to a single location. Olly

Have you two weather stations?

Thank you very much! The Saturn's and Jupiter's images are not my own. Because I don't have such a good cam. Therefore I posted a picture from the internet in the way that I see them for real. But the moon pictures are completely mine. Yes, they are afocal images. I have also more prime focused images which are really good. These are my first prime focused images. Thank you. Nikolai.

Hi Mr Spock Do you mind me asking which brand of variable polariser you used? From reading other threads it also looks like having a O-III and UHC filter can enhance certain objects like nebula and planetary nebula. Do you have either of these? Thanks

This Skywatcher 150i mount looks quite interesting...

I think Spocks keep on trekking, surely?

I do a bit of that when the moon is bright as well. Adds some variety 🙂 I've packed in now (wimp !) - keep on trucking @Mr Spock 👍

Balance is ok. I had no issues tracking for the past 3 months I had it and it just stop tracking at the azimuth.

Just took in half a dozen bright and familiar doubles. Back to the moon now:-

Quick snap with the D500 taken just now - 00:45 in the morning

How is the balance of the scope? The clutch can only lift so much, and heavy eyepieces, etc., might be too much for it to handle. If that’s the case, a counterweight on the lower half of the scope might be the solution.

I've an OMI mirror, tested at 532nm (green). Here's their tech note on interferometry results: https://web.archive.org/web/20080509195633/http://www.opticalmechanics.com/technical_articles/interferometric_testing.html The numbers quoted for your mirror are very good!

I notice in the Tak the field curvature seen in the f5 Newt isn't there. I'm guessing therefore it's f related. From 8 all the way down to 3 it's turning in a great performance. The difference between it and high end eyepieces is very small indeed and you could be happy (as a refractor owner) with this as your main eyepiece. I think f5 Newt owners should look elsewhere. For the money it has to be the best bargain ever.

No, you don't need to ever justify a purchase to anyone else (except perhaps your family CFO, if you know what I mean). I'm just trying to figure out what I've been missing with this scope. I'll try some more widefield viewing with it.

Also depends on the OEMs QA requirements including salt spray test specification as to what methods they use. I find for DIY spray paint works well, ensure its done in a ventilated space, if outdoors try not to do it during a breezy day and in an enclosed area as spray travels far in the air (be sure to mask areas if space is limited). Do it in a reasonably medium temp, too cold and there's risk of moisture being present, too warm and it doesn't set (finish) as well but dries quicker. Spray lightly in a few passes intially (say moving 30cm in a second, over again say 3-5 times), then do a thicker slower one time pass on top being careful not to cause drip marks (too heavy/slow with the spray movement). Two or three times with this method leaves a nice even finish as without the quick pass layers the heavy layer is uneven and dries as such. I've done this to match original powder coat quite well as well on vehicles.

Having a great lunar session. Seeing is quite good if a little wobbly. It's the long period wobble you get sometimes. Gassendi N is resolved into a crater and is a fine sight with the rille next to it. A good chance to evaluate eyepieces again - full report to come. The Svbony 3-8 field curvature I noted in the f5 Newt is not evident in the f7.4 apo - interesting. Comparing the 3mm setting, it's very good, falling just short of the 3.3mm TOE and 3.5mm LVW. I prefer the view through the LVW, it has that 'easy on the eye' feel to it. That's another eyepiece better in the f7.4 - in the f5 it's too easy to get blackouts from incorrect eye position. Same. It's an interesting feature. Shame I didn't have the 12" out so I could get a bit more magnification. The south part of the Schiller Annular Plain, or whatever they call it now, is very prominent. Going back out now - there's so much to see yet!

Another slight show from the Aurora, it was very active earlier before dark, ok for the Southern hemisphere. Dodgy phone pic

It's down to one thing in reality: electrocoat. The bodyshells are chemically cleaned in an acid-dip then electro-plated with an epoxy basecoat. This being electro-plated means it achieves 100% coverage, inside and out. It's the layer under the primer and unless it's damaged it'll outlast the vehicle's lifespan.

Interesting, thanks for all the responses. I lean towards Bill Paolini’s thoughts as presented by @JTEC, but local opinion seems to be evenly divided. As for adding heaters to secondaries, I’ve avoided that for the same reasons, and decided that dew-opacity signals “end of session”. Luckily I’ve found that there’ve been overall surprisingly few heavy-dew nights, and this is Ireland! Magnus

Step 1: sandpaper or paint stripper the existing paint off. Step 2: kill the rust. My preferred method is phosphoric acid. Nasty stuff, must be used with a lot of care. Proprietary rust-killers are also available. Step 3. primer, from local motor factors. Step 4. enamel or similar topcoat in colour of your choice, also from motor factors.

Cars have extensive multi stage pre treatment done to the metal as prep prior to paint including galvanisation where applicable. Once the surface gets rust or the bare metal is exposed it's pretty much guaranteed to rust again. Even aluminium goes through similar pre treatments. The best you can do is advised, use a mechanical means to grind the rust off if present (dremels are useful things to have lying around, or a 4 inch angle grinder) unless the corrosion is not too much of a concern.

In these photos, what I am looking for?

Thanks. It seems that I have lost torque to turn the wormwheel and brass when 'tracking' although at higher speed it works; this is with no clutch and large wheel?. Hmmm After shutting down and restarting it turns with and without the wheel?? Most peculiar