Captain Scarlet

1 hour ago, Stu1smartcookie said:

A lovely image where , for once the clouds actually play a positive part in a photo . 

 

Shhh! Don’t tell the clouds - they’ll get ideas!

I had a good look at Mercury tonight, naked eye, through my Kowa 88mm spotting scope with 20-60 zoom, then put in my DeLite 3 to give me 170x. There was atmos CA, but the phase was obvious and it’s the highest mag I think I’ve ever managed to get on it.

I don't want to be left out here. I hope you don't see red about my new sig...

Magnus

31 minutes ago, John said:

When Jupiter was higher in the sky in past years I've had a similar shock observing with my 12 inch F/5.3 dobsonian. Especially when there was still plenty of light left in the sky - the colours seemed even more startling then.  

I only started observing when Jupiter was down at the start of its “low years”. Now it’s going to be higher and higher over the next 2-3 years I cannot wait, especially as I now have that much more experience and equipment. I am one of those who has still not had anything near a startling view of the planet. I have properly just about discerned the GRS and its colour only once.

To fill the gap between my 1.6 and my 3.0, DHL kindly delivered this just now:

It’s surprisingly heavy.

Magnus

I use an app called Moon Maps, which shows about 50 photographs at various mostly 0.5 day increments of phase. You can reverse and/or go south-up, and it’s annotated.

17 hours ago, andrew s said:

For any reasonable system the damping due to the inertia of the mount/telescope system should put any drive induced blurring well below the seeing psf.

Regards Andrew 

I'm not sure I'm completely convinced. I'll go away and experiment, I have some useful tools which should shed some light.

M

Until very recently, for 4-5 years I was exactly the same. But I’ve lately got a medium-sized refractor and now positively look forward to all moon phases except around Full. I have no excuse: I have had long focal-length Maks for all that time and I really should have become a Lunatic much earlier. Better late than never though, I strongly encourage you to follow suit 😁.

29 minutes ago, bosun21 said:

I reckon that if any vibration was transferred to the telescope and optics then our astrophotography friends would have discovered it and wrote about it long ago.

Well I have to say that even when I look at the supposedly very best astro-photos, and for extended objects they are incredible, I always think to myself: wow stars look so so much better through an eyepiece than ever they do on a photo.

I was chatting to a fellow SGL friend today about this, and relating how convenient “tracking” is for observing at very high magnification. You simply sit and stare and do not have to break contact at regular, frequent, intervals.

But always, right by my ear, there is this bzzzzzzzz of the motors gently running to keep on target. I was wondering how much of this bzzzzzzz finds its way to the OTA and induces a vibration-induced blurring. I should add I am talking here from a strictly observer’s viewpoint.

My main go-to mount (in both senses of the phrase) is an az-eq6, especially for my bigger scopes which will more likely be used at high magnification. I think it’s belt-driven, but even so the belts will be in tension and therefore of limited damping use?

I wonder, does anyone have experience or views or links about this?

I might attach an accelerometer set-up (if I can find it) to my rig to see what that shows between tracking and stopping tracking. Maybe even a guide log from imagers might yield useful info? Even my iPhone has some apps that might be able to show a frequency spectrum.

Cheers, Magnus

A clear night and no wind, after days and days of howling gale and rain. I had the SV 140 out on the Moon, and it was fantastic. Vixen HR 1.6 giving 586x was perfectly doable, occasionally wobbly but mostly sharp. Backing off to 313x with the DeLite 3 was stunningly 3D on the taller craters. Some intermittent cloud but a very good session ended by battery running out of juice.

I concentrated on the area between Lacus Somniorum and Mare Tranquillitatis, especially craters Atlas and Hercules and the area Rupes Cauchy, according to my moon app.

I might do a proper obs report, not sure.

I managed to resist the 200K that just went on eBay for £400-odd, but I was _very_ tempted. I have an Intes M603 (sorry am I allowed to mention it on this exclusively TAL thread 😜?) for which I paid £300-odd, refurbished and is very very nice. Which puts into perspective the 7” Intes that’s currently on offer on our classifieds 😳

There is a piece of free software you can easily get for your PC which will tell you the “shutter count” of any camera connected to it. Your friend should certainly be able to tell you that anyway. I have a bunch of white lenses, but the ones I tend to use for night time wide angle are all Samyang (aka Rokinon), including the 24/1.4 and 85/1.4 . At 1.4 they esp the 24mm tend to be a bit flarey on very bright point sources but at f/2 they are superb. Manual focus so I’ve taped the infinity position.

So yes I do have lenses suitable for the Aurora but sadly down in West Cork I don’t have Aurora suitable for the lenses!

I have a canon 6D. Superb camera, and full frame - if it’s in good condition I’d take your buddy’s one from him

Well I am part Finlander (half) and I must admit I’ve never seen the Aurora. Amazing.

Magnus

17 minutes ago, vlaiv said:

You can practice on Galilean moons first?

They are 1.8" down to 1" when Jupiter is closest to us and smallest apparent diameter of Europa when Jupiter is the furthest (0.665")  is about the size of Ceres when it is close (it ranges from 0.34" to 0.854")

I could but I'll have to wait nearly a year before I get the chance, I fear

2 hours ago, JeremyS said:

Hello  Agnes @Captain Scarlet. Coincidentally in the last 24h someone has  discussed resolving Ceres on CN

https://www.cloudynights.com/topic/869026-ceres-possible-resolution/?hl=%2Bmewlon+%2B210#entry12582322

The message I get from that thread about being able to resolve it is “highly unlikely”. Certainly not in my 140, and the combination of factors that need to come together to make it possible in my 12” are too much I think. I’ll try though given a chance.

Excellent information, thank you. I too only recently found out about Ceres at a talk I went to just over a week ago. By luck, a couple of days later was a clear night and I was able to observe it. It's more or less at opposition now, so a perfect time to see it. It's just off the tail of Leo, and will pass "through" the M100 galaxy around 28/29 March.

I think he’ll do whatever tube size you want. I initially ordered a tube to replace the one on my SW 300p, and he said don’t worry about specifying the size, I have just such a SW cell as a template. Unfortunately SW must have slightly changed their 300p cells at some stage, as the tube was 2-3 mm too big in diameter (I did ascertain with him that it was indeed two slightly different cells, not his craftsmanship). Luckily too big rather than too small! So I shimmed it. Eventually I replaced the SW cell entirely with an OO cell which I knew in advance I was going to have to use 9mm of spacing on each of the three corners.

The 200mm tube I ordered to fit my VX8 cell, and that fit pretty well straight up.

The only other suggestion I’d make is give it extra length, effectively dew-shield and long baffle in one! I did that for my 200mm you can probably see from one of the pics.

M

Edit: to answer the extra questions I’ve just noticed. Yes I did all my own holes after the original SW-cell ones. And I was actually able to re-use all the spiders too. I used some modified flat-plate door hinges to give me extra circumference for the 200mm tube, which as @ONIKKINEN says below has a larger external circumference because of the thickness of the tube.

Indeed yes I have two of his tubes. One for a 300mm mirror and the other for a 200mm mirror. They are extremely stiff, and I cannot fault them. I went for the carbon tube lined with 6-7mm of hardfoam, which in addition to helping the  stiffness, provides better purchase for accessories bolted on to the tube such as focuser, finders, spider and main cell. The only stipulation I would recommend is to drill your own holes. You can do yours at leisure going up 0.5mm at a time, whereas he does them more quickly. Re the focuser hole, drill a pilot hole of course, but for the main event use a sharp hole-cutter _backwards_. 
BTW I didn’t regard them as that expensive for what they were. But it was 1.5-2 years ago.

Cheers, Magnus

PS @ONIKKINEN also has a CH tube I believe.

21 hours ago, John said:

Nice report Magnus, great looking scope in a wonderful location too 🙂

On the apparent diameter of 1 Ceres, Stellarium gives a figure of .83 arc seconds which is co-incidentally similar to the apparent diameter of Jupiter's moon Io.

With the Galilean moons I have found that it is possible to notice differences in what appears to be their apparent diameters with scopes of 100mm or more aperture and from this I have been able to work out which was which on a particular night without looking up their relative positions.

The challenge with 1 Ceres is that there are no nearby objects in the sky with which to directly compare it's apparent diameter with, in the same field of view, so it may well be rather difficult to work out if what you are seeing is it's true disk or something more akin to an airy disk as you get with stars. Maybe that is also the case with the Galilean moons but there are definitely visual differences in apparent size between them whether though varying airy or true disk diameters.

I guess that does not really answer your question - I would be very interested to hear what others think 🙂

Thanks for posting your report and that lovely photo 👍

I can easily see Uranus as a disc, it's 3.5 arcsecs. I can just about detect that Neptune is a disc, at slightly over 2arcsecs, but that may be difficult because it's also so dim. But I reckon Ceres at <1" might be beyond my disc-detectability. I'll try with my 12inch at high mag the next time I try, and see what I see.

After weeks of drizzle and fog, not surprising at my heady altitude of 93 metres (air’s pretty thin too) Saturday night was suddenly forecast clear. The Moon well out of the way too, so ordinarily I would’ve set up my 12” newt to take maximum advantage of the dark. But I’ve been itching to get some more use from my latest toy, my SV 140 refractor. I went for maximum convenience, setting up on the patio right outside my door with a Northerly view but spanning 180 degrees left and right over the creeks and Islands.

I also cobbled together a quick list. As mentioned, I had my new Stellarvue SVX140 on an AZ-EQ6/Planet. The night ended up measuring 21.7 on my SQM-L. Seeing seemed OK, transparency good to start, but deteriorated later on. I aligned using a DeLite 18.2 (52x) and settled for most of the session on my Delos 6 for 156x, occasionally rising to my DeLite 3 for 313x. Towards the end I used my gorgeous Nagler 31T6 for 30x.

A week or so ago, I drove to Cork (90 minute drive) to listen to one of Cork Astro Club's members give a talk about Sundials, his speciality, and I hadn’t realized it also doubled up as the Cork Astro Club’s monthly meeting. So I also sat through another talk, given by their observer-in-chief, about what was going on in the night sky this season. I learned that 1 Ceres, the brightest (by far: Ceres is mag 6.9, the next is in the teens!) asteroid/dwarf planet in our Solar System, was near opposition and eminently observable. Thus my first objective was 1 Ceres, which I’d never heard of before let alone observed.

I now know that 1 Ceres is an asteroid, but last night I knew it only as a dwarf planet, and none of the 60-odd catalogues available to me in the Nexus DSC seemed to fit the bill. It does have a couple of asteroid catalogues but like I said… . So I resorted to a fancy new modern technique that I’ve recently heard about called “star hopping”. Looking it up in SkySafari I found my way from Denebola to Messier 88, hopped up a couple of viewfinder-widths North and West a bit (IIRC) and matched the star-fields: Bingo! Mag 6.9 so it was the brightest thing in the immediate vicinity, but no disc discernable. I’ll have to do the calcs to see if a disc was too much to expect. Maybe someone can chime in to the flood of comments after this 😊.

I wanted to see Herschel’s Garnet Star, aka Mu Cephei, and remind myself just how red it is. I found it easily enough, and yes I could see it was a bit orange-ish but that was it. Perhaps I should have treated it like a planet and looked at a bright white screen to activate my cones to get the colour better, I might try that next time.

Next was another red star I rather like, the central star in M37. Again, underwhelming, the same could be said for the whole cluster, actually. It turned out there was a reason for both this and Mu Cephei being a bit dim.

I could see Vega and Lyra were now possibly far enough up to be worthwhile, so I went for Eps Lyrae (The Double Double) at 156x, to be greeted by two pairs of tiny but perfectly separated dots, and no discernable diffraction rings. One of my favourite targets, I stayed for a while here. Whilst still in the region, I quickly and casually star-tested on Vega: perfection as far as I could tell.

I had M35 on my list, not sure why, it was nice enough if I recall. At this point I changed to the Nagler 31 to give me my widest field of 2.7 degrees and 30x magnification. M35 suddenly looked much more compact! I love the wide fields a medium refractor gives you.

At this point I decided to finish off with NGC 1502 and Kemble’s Cascade, to see if I could identify any star colours in Kemble’s Cascade – it’s supposed to be famous for those colours. NGC 1502 is a small OC at one end of the asterism, and it was dim and slightly underwhelming. I “got” the Cascade, but not impressive and certainly no colours. Hm. I looked up and suddenly the mystery was solved. I could, naked eye, barely see even the Cassiopeia “W”. That northern aspect was veiled with cloud, explaining as well my earlier view of Mu Cephei. So that was it, time to pack up.

I’m still very much enjoying this scope, and it was good to get anything out even for a short session after all the solid cloud we’ve had recently. I was especially pleased to see 1 Ceres.

Thanks for reading, Magnus.

Curt welcome back, I feel you’ve been absent a while? Or is it simply there haven’t been any noteworthy events lately?

I observed Ceres last night through my SV140, first time ever seeing that asteroid. I looked for a disc-like shape but without having done the calc I daresay it’s far too small to expect to see a disc.

I hopped up from M88 to locate it.

Cheers, Magnus

Just in from a moderately satisfying night with the new Stellarvue 140, curtailed in the end by creeping haze, everything suddenly seemed to have developed nebulosity.

Highlight was a new object for me, Ceres, the brightest of the dwarf planets, currently a bit north of M88 which is how I managed to pin it down.

Only third light for the new scope, full report tomorrow in that section.

Magnus