Captain Scarlet

@markse68 might be familiar with the locale as well?

10 hours ago, Sunshine said:

Observing in the rain! that is some commitment!

lol just a little shower that came through and clear after - well forecast so I came prepared 😁

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

1 hour ago, John said:

Not quite night yet and cloud may still spoil the fun but the simple 8 inch dob is out and waiting. If it stays clear the scope will get to use more of my Ethos eyepieces 😁

Mimas seems well-placed again tonight.

This was me last night when a (forecast) mild squall came through (otherwise a superb session):

I have both a Paracorr2 and a Nexus DSC (not the pro but the only difference is the pro has a later chip more memory, functionally I think they are almost identical). I wouldn’t be without either.

I nearly sold my then wide field eyepiece (Pan 35) a couple of years ago as the outer-field stars were so bad in my 12”. It then occurred to me it might not be the eyepiece at fault, I did a bit of reading up, bought a Paracorr2 and magically the coma disappeared and what had been intolerable became beautiful (Double Cluster through a 12” at wide field from a dark place is really something else).

The Nexus is extremely capable, is able to work with an equatorial platform and has every conceivable catalogue built in, which you can filter in and out “in the field”. I use mine in native mode, but you can connect it to SkySafari and use that as your control as well. The only thing I’d advise is get the additional GPS auto-location feature on it, I think that may be an extra on the “pro”.

You should also be able to use the Nexus to control your AZ-EQ5 if you still have that: you can store settings for several mounts in the Nexus. It completely replaces the SW handset.

Looking forward to see how you get on.

Magnus

19 minutes ago, John said:

I'm pleased that you saw Mimas with your 140 Magnus.

I think I managed to see it a few weeks back with my ED120:

I'm not sure that anyone believed me though 🙄

It was quite odd. I was also comparing my various ortho-style eyepieces, and the first I put in was my BCO 10mm (first light for that), for only 94x but that initial view was the best all night by far. Tethys was below the easternmost ring-edge and a much fainter but perfectly obvious and sharp Mimas was above. I struggled to get it with the Tak LEs and TOE at higher mags. But there was cloud steadily rolling in as the night went on so that might’ve affected comparisons.

Just in from a mostly clear night. Only planets, with the 140. Seeing around Saturn seemed really good. I wanted to get as many moons as possible and managed Titan, Dione, Rhea, Tethys, Enceladus, Mimas and Iapetus. I tried hard for Hyperion but no luck. Jupiter again the best I’ve seen it. And I also found the Lunar Crater Clerke, named after Agnes Mary Clerke, born very near here, who was responsible for our recent storm Agnes.

Worthy of a full report, will write it up tomorrow.

Cheers, Magnus

On 30/09/2023 at 16:20, Ratlet said:

For my favourite child.

Don’t let your 10” know! It’ll put it right out of collimation.

15 hours ago, Nyctimene said:

- and twice another winged creature, with a zig-zag movement pattern, 

Nazgûl?

I’ve heard that Hotech laser collimators are reliably true out of the box. Although not dirt cheap, they are not crazy like the Glatter ones. £145 from FLO. @Stu has had experience of them I think.

It could be argued that the centering is actually less important for AP than for visual, because you can even out the illumination with flats.

Collimation is the process of aligning the optical elements. In a Newtonian, that means aligning (making coincident) the axes of the eyepiece and the primary mirror. Which in turn means somehow aiming the eyepiece axis directly at the centre of the primary mirror; and aiming the axis of the primary mirror directly back at the centre of the eyepiece tube. Both these two steps can be done independently of the other, luckily.

In a perfectly-collimated Newtonian (using a laser and barlowed laser, as it's easiest to describe):

1. a perfectly-collimated laser-pointer inserted in the focuser tube will strike the primary in exactly the centre (using the tilt of the secondary as the beam-director);

2. (using a Barlow in front of the laser) the reflected shadow of the primary's centre-marker should fall exactly in the middle the face of the inserted laser.

Once you've achieved 1 & 2, the Newtonian is collimated.

Two things, though:

i. notice I've not mentioned anything about "centring the secondary". A Newtonian can be considered collimated according to the definition above (aligning the optical axes) almost regardless of how well-centred the secondary is. The actual _location_ of the secondary only affects illumination levels across the image. A thought experiment: if you place black tape across four edges of the secondary, rendering it rectangular, of if you snap off an edge of the secondary, the scope is still collimated. Obviously, for ideal illumination, you'd like the secondary to catch as much of the returning light-cone as possible, but getting the secondary to appear "round" is far less important than the alignments.

ii. almost all techniques for collimation require the centre-spot of the primary to actually be in the centre. In both primary mirrors I have measured, this was not the case, one grossly so.

Magnus

I find the site www.lightpollutionmap.info the best for predicting LP levels. Select the "Atlas 2015" tab, which shows a modelled prediction of what your SQM might be based on the then-latest VIIRS readings from above. I find it to be quite accurate, based on lots of SQM data I've collected over the past few years at two different sites, one near London and the other here in rural West Cork. On the map, simply click where you want to check and a pop-up with estimated SQM will appear.

Cheers, Magnus

A perfect illustration of how scope volume and weight varies as the cube of the linear dimensions. 8” => 12” is only a 50% increase in linear, but it increases the volume and mass by a factor of 3.5!

I’ll put up a pic of my own 8” and 12”, of similar f-ratios, and my 105 & 140.

Magnus

I’ve only acquired one thing I regard as a total dud. As a beginner my starting-out kit included a skymax180 (still have it - it’s great); az-eq6 (likewise, my workhorse and it’s never failed me); and an external focuser for the skymax, a TS 2” Monorail. That focuser was so bad I couldn’t in all conscience sell it on. Its fine-focus knob was “springy”, so that the springiness was always much greater than the last bit of travel needed to get to focus. I tried to adjust it, and in dismantling it managed to effectively destroy it, so it sits in its box still, accusing me every time I come across it.

Magnus

Well done, what a great move. I know _exactly_ your feeling, having made a similar move 3 years ago. My list of naked-eye revelations include (in no particular order): M31, whole of Ursa Minor, Double Cluster, M44 Beehive Cluster, Coma Cluster. Whenever I see any of those I think back to my time in London and what I could see there and feel mighty lucky.

ENJOY

Magnus

I have managed a 14.7 star with my 5.5” refractor, so in the right sky (my sky) on the right night I would certainly expect to be able to get a 14.5 object in a 10”. Perhaps star vs galaxy are different for same magnitude?

Given the chance, I shall certainly have a go. I’ll try to try with both my 8” and 12”.

Magnus

On 15/09/2023 at 18:57, Mr Spock said:

I store my 12" on its mirror end. It's too heavy to turn upside down.

 

Very nice set-up. You’ve even got your collimation tools hanging up behind the OTA 😉

Magnus

I feel sorry for the poor Astrophysics expert who made themselves look foolish 😟

5 hours ago, Mandy D said:

What a wonderful night, for you! Then to cap it off, the aurora.

Sometimes, I forget what I am mising by not doing so much visual. I also have a 300 mm Newt and the 50ED which I was using as a finder on it. I agree that it is a wonderful little scope and for relatively so little money. I've now repurposed it for deep-sky astrophotography with my my ASI 178MM.

It really is worth overcoming the inertia of all the bother to get the 300mm out, as long as you have a sky dark enough to warrant it, which in Derbyshire you probably do? When I was in London I never bothered with anything more than an 8”.

M

On 08/09/2023 at 20:03, Paz said:

I've never hear of these before but I've been on a constant look out for ways to balance different eyepiece weights and this looks good - can you get these in the UK, I've had a quick look around but can only find them the other side of the pond.

My current arrangement is I balance my scopes with the heaviest eyepiece I'm planning to use and they when lighter eyepieces are used if the difference in weight is enough to matter I screw smallrig weights into a finder shoe to keep things about right.

When I ordered my SV refractor I added this to the purchase. It looks v good but I’ve not used it yet.

https://www.stellarvue.com/cw-1-counterweight-system/

1 hour ago, Paz said:

… heroic … deserves a medal!

I used to think the same 😁, until I got a wheelbarrow. It totally transformed the setup and tear down chores.

I was beginning to fear I was getting out of the habit of observing, being so easy just to find an excuse and do something else, or simply go to bed. But I couldn’t ignore the forecast yesterday, and I’d had nothing to tire me out during the day. In the end it was a memorable session with a huge bonus at the end, well worth a next-day-wrecking 3am collapse-into-pit.

So, before dinner, most of the clobber (15kg of counterweights, AZ-EQ6 mount head, Planet tripod and big rings) went into the wheelbarrow and around to the field at the back of the house. I levelled and set up and went back inside to await darkness.

After dinner I headed back out, carrying the night's OTA, my 300mm Newtonian. The transparency was immediately obvious: Milky Way the best I’ve seen it this year, and M31 the “most naked eye” I can ever recall seeing it. SQM-L readings through the night were consistently 21.5 with the MW directly overhead.

I’ve been messing around lately with finders. I have two Telrads, but they are ridcuously dew-prone, and I’ve retired them (I plan to put them up for sale). I recently got a third SkySurfer V, taking my harem of in-service finders to those three SkySurfers, an APM 8x50 and my amazing EvoGuide 50ED/Pan24 (10x50). So I’ve been vacillating about which to allocate to which scope, swapping them around between my six OTAs. Consequently, I found myself last night with two non-pre-aligned finders, a Baader SS V and the EvoGuide50. Foolish error. I was forced, in the dark, to attempt to align my finders to the OTA. Which also meant trying to get the 12” pointed at something I recognized.

I tried the “unaided Polaris” route first, on the basis that Polaris doesn’t move while I’m fiddling about, but wasted at least half an hour failing to find it at 59x, not least because at 59x with 12” aperture, there are just too many stars. Luckily by then Jupiter had risen enough to be useful, and I used him. I found the planet easily enough by getting into the vicinity and using his huge wide diffraction stripes crossing the field of view to “guide me in”. Aligning the finders was then easy enough.

About the SW EvoGuide 50ED. I’ve managed to convert it into a finder by adding a super-short-light-path Baader T2 diagonal and extra-short eyepiece clamp. My Panoptic 24 eyepiece seems unique in having just enough in-focus accommodation to allow the whole to focus, making it a 10x50 ED finder. And what a Finder it is. The view through it is better than that of my Leica Ultravid 10x50s. Throughout the session I effectively had two very high quality scopes within 2 inches of my left eye. Going from 10x at that quality, to 183x or 59x (which are what I used most of the night) was such a joy.

After the fiddling around, I went first to Saturn.  He was just above a 200 metres-away neighbour’s house, and it was interesting, at 183x with the Delos 10, to see Saturn alternately being sharp, with Rhea, Tethys and Dione (and bright Titan of course) sharply in evidence, then a few seconds later all disappearing and Saturn a mush. And then back again. I’ve not experienced such regularly-variable seeing before, and from such extreme to the other. I returned to Saturn several times, and it was always like this. I tried the Delos 6 for 305x, but even in the sharp moments that was too much.

Next of course was Jupiter, which was a horrid blue-red fringed mess, being so low. Later it was much better.

I had in mind a globular cluster in Delphinus, my favourite constellation-asterism which just leaps out - seemingly literally – when you find it in the sky. I have a small boat which I’ve named Delphinus with a little diagram of its stars. Anyway the glob is NGC 6934. It’s quite small but resolvable in the 12”.

I followed that little glob with our king of globulars, M13. As ever, hugely impressive, and more so than I recall lately. The Propeller was immediately obvious, which it isn’t always. I headed across to the nearby faint galaxy NGC 6207 which for some reason was less obvious than I recall it from previously. Although there was a distinct core and halo.

After M13, and having read that M22 is a globular cluster to rival it, or would be if it were ever high enough, I tried for M22. Alas it was already past my Western-most tree-boundary and I was too late. Next time.

Although transparency seemed as good as I’ve ever seen it here, seeing was only so-so. I tested this by moving to epsilon Lyrae, my “Seeing-Diagnostic”. Yes they were all an easy split at 183x, but by no means crisp and clean: a long way from my night of utterly perfect seeing with the SV140 back in May. I did notice, however two extra field stars between Eps1 and Eps2 that I’ve not picked up before. It turns out they are two mag 12+ stars with 15-character GAIA names. The mag 10 star, TYC 3122-1635-1 just offset from eps1&2, I always notice.

Whilst looking through the Finder at 10x a nice-looking double nearby caught my attention, turning out to be zeta 1&2 Lyrae, a pair of white stars at mag 4 & 5. Also in the vicinity I stumbled across whilst slewing a beautiful wide-spaced pair, one bright orange, the other greenish-blue. They were delta 1&2 Lyrae. There’s quite a lot of loveliness in Lyra, even just bumbling around as I was.

In my perfect-seeing session in May with the 140 refractor, I managed to glimpse a mag 14.7/14.9 combination star just near M57. I wanted tonight to see how different it would be tonight with more than twice the aperture. Well, I was able to see that very-difficult-in-the-140 star quite easily, and an extra two dimmer ones nearby, one hovering on the edge of detection. Looking up using @John’s diagram, (thank you John) it seems those extra two are 14.7 and 15.3.

Now it was time for The Veil Nebula, and was I in for a treat. I fitted my Baader Oiii filter to my big Nagler 31, and headed to 52 Cygni. Of course, with the filter, the Western Veil leapt out, and 1.4 degrees from 300mm of aperture, the 5mm exit pupil maxing out my own pupil, gave a great view. I panned around, finding the Eastern Veil which seemed brighter than I recall from previously, and lots of wisps in between, one obviously wedge-shaped. I guess this was Pickering’s Wisp which I’ve sought but never conclusively “got” before.

I’ve observed and enjoyed the Veil many times, but despite numerous attempts using all combinations of equipment,  including this 300mm, I’ve never managed to see it without a filter. So it was without much expectation that whilst pointing at the Western part I removed the Oiii filter, put the N31 back in, and re-applied myself to the eyepiece. Well blather me – there it was, perfectly obvious with direct vision, sans filter! I was beside myself. After so many tries. Without using go-to, I tried to find the Eastern part, and it hove into view, quite obvious. Absolutely bloody marvellous. I took a wander around the clearing congratulating myself.

By now Jupiter was somewhat higher up, and putting the Delos 10 back in for 183x, I was treated to amongst the best views of the planet I’ve had. Though that’s not saying too much. I’ve never had the startling crisp view of Jupiter that others describe, and I didn’t have it this night either. But extra belts were on view with occasional extra detail, and that was fine. It was still too low and there was still a hint of residual atmospheric CA. I look forward to Jupiter rising as this season progresses. “Perfect Jupiter” is still in store for me. A bit like me envying people who’ve never yet read Lord of the Rings (film doesn’t count).

Uranus was next, nice round blue disc. Quick look for Titania or Oberon, nope. At mags 13.9 and 14.1 they might be possible?

I put the Nagler 31 back in and went for M31. I was getting cold and tired by now so didn’t go hunting for some of the objects within M31 itself. I’ll have to dedicate a session to that and those within M33. I made do with the Andromeda Galaxy’s lovely dust-lane and structural wide-field detail, including M32 and M110. Oddly, M33 was unimpressive tonight.

As a finish-off, I opted for a couple of open clusters. M45, Pleiades, was first. Although I was tired, the sheer startling brightness and myriad stars of M45 woke me right up! And the contrasting views between the exquisite 10x of my finder and the banging brightness at 59x from 300mm was a revelation.

I tried the same trick with the Double Cluster, and it was even better. I’ve observed this many many times, and the view through the 10x finder was familiar: it’s always a binocular object for me. But with the Nagler 31’s 1.4 degrees getting both clusters in the same view, at such brightness, it was indescribable. Such tiny, pinpoint, delicate structures, chains, twirls and colours of stars. It was as though the Double Cluster was an entirely new object. In particular I noticed a couple of rather red stars sitting between the two main clusters.

So that was it, and it also suddenly occurred to me at the end: virtually NO DEW. Incredible. I packed up and went inside some time after 2am, to decompress, make a quick post on the “what did one see tonight” thread and go to bed.

Then my phone buzzed. “AuroraWatch Red Alert. Major Activity etc” so I rushed outside and immediately to the North saw shimmering vertical columns of grey. I rushed back inside to grab my canon 6D/Samyang 85/1.4 and got a few frames. Before April this year I’d never seen the Aurora Borealis. Tonight’s was not quite as strong as April’s, but unmistakable naked eye nonetheless. Pure icing on tonight’s cake.

The photos below show it as the camera saw it, and after a bit of fiddling in PS, exactly as I saw it naked eye: i.e. distant streetlights still yellow but the sky and Aurora itself in greyscale with just the slightest hint of colour.

Thanks for reading, what a wonderful night. In bed finally at 3am, and wrecked the next day.

Magnus

Just in (2am) after my first proper session in 2 months and my first with the 12” in 4 months! Though there was one a few weeks ago where I got it all out in the daylight evening and simply packed it away again once dark (clouds).

A really good session, incredible transparency, and a couple of new objects for me, the glob in Delphinus to name one.

Worthy of a full report which will follow tomorrow. And I’ve just got a “red alert” Aurora message, so I’m heading out again!

Cheers Magnus

Edit: and I saw the Aurora! Again, amazing.   Not as strong as April’s but unmistakable naked eye nonetheless. Vertical sheets of shimmering grey. I got some pics which I’ll retrieve from my dslr tomorrow also. What a night.