chiltonstar

Nice shot Steve - a lot better processing than my attempt! I caught the transit earlier on (23:30 to 0010). Io is to the right of the shadow in this prelim image. The splodge to the right of the GRS is interesting? Chris

You were lucky to get out Doug - no luck here. I have my ED80 and Vixen Porta2 waiting as a grab 'n go in this kind of weather, as it is ready to go in a minute or so unlike my maks, and can give some glorious views. This kind of weather is dangerous, as we all end up window shopping supplier websites! Chris

When I've looked at the moon at low mag without a moon filter, I've occasionally had a visual migraine afterwards. I do have a moon filter now, but I have to say it's not very good optically and reduces visual detail a little. Chris

Quite impressive, even with cloud. Chris

As I was in London at the time, I assumed it was over Southend...... Chris

When I started in astronomy there was a very bright star in the east........... Chris

TVM for this Stu - very useful indeed! Now all we need is a clear night or two! Maybe if FLO close down for the Summer to prevent the new kit jinx? Chris

The Stelle Doppie figure for PA is 277 degrees which matches what we both saw I think. The blue of the secondary may be aperture dependent as I would say with 180mm it was definitely blue-green 'ish, although of course with atmospheric refraction and seeing wobbles, colour is always a bit subjective! On my original, the intensity ratio looks right, but shrinking the file and copying across has made the intensities look more similar. Unfortunately, my laptop was also trying to perform a couple of updates (G knows what) which corrupted the image file slightly. This is the 100mm simulation with the blue-green intensity reduced to something more like the correct ratio (it makes the colour slightly more Blu Tack'ish maybe?):- Chris

I've done it in the past with an 80ED - I don't think aperture is the main issue really, it's more about seeing and as John says, having a clear S aspect (and of course having any clear nights). This is a simulation (Aberrator) of Antares with a 180 mm Mak and a 100mm frac - you can see both can split it easily; I've added a bit of colour for fun! Chris

At UK elevations for the gas giants, normally x150 to x250 seems to be the best range of mag, although I have used much more when they are higher in the sky. Chris

The rain cleared the murk here a little and Jupiter was visible as it should be - a worthy competitor to Venus! At 11 degrees elevation though, the seeing was far from perfect, with fractions of a second of detail every minute or so, with the GRS nicely visible. Later, when Jupiter is higher, I have a house and some trees inconveniently positioned so it was 11 degrees or nothing! Best seeing I've had for Jupiter so far this year though. This quick image shows the amount of detail I could (intermittently) see (180 Mak, AS1224). Oh for a more southerly location! Chris

With their excellent reputation, I was a little surprised by the optical test comparison by Wolfgang Rohr of the Mewlon 180 and the standard SW 180 Mak, in which the Synta product had the better optics apparently:- http://r2.astro-foren.com/index.php/de/12-beitraege/04-zweispiegel-systeme-astrofotografie/789-d069b-vergleich-180-mewlon-dall-kirkham-und-180-skywatcher-maksutov I may have an opportunity soon to look up both scopes side-by-side, which will be interesting. Chris

60 degrees ........wow! I split it again two nights ago, and I had to use a much lower mag because of the near horizon seeing - x90 gave the sharpest view of the blueish-green secondary, nearly due West of the primary. Chris

...clouded out here. There was a persistent bank of cloud in the SSW. By the time it had cleared, Jupiter had swung round too low for me behind some trees. Annoying! Chris

Trouble is, you don't know if it's clear until you've got up........ Chris

One of the amazing things about Jupiter - there's always plenty of action! Chris

I've split the pair twice with my 180 Mak - not easy though. A neighbour has an annoying tree which gets in the way, but I have found a spot in a field with a low southern horizon which is ok. There are not many evenings though when Antares is in the right place, there's no low cloud, and the seeing is excellent or better! Chris

For the early birds, there is a nice double transit of Ganymede and Io and their shadows early on Wednesday morning around 02:00 am, when Jupiter will be about 15 degrees above the horizon (S of GB). Current weather forecast has a clear spell about then, if you believe weather forecasts..... Simulated view (SkySafari) below Chris

Might be the ozone generated by the uv of course? I UV irradiated my lens after assembly with a mercury vapour lamp I have. Chris

In older lenses, it used to be the Canada Balsam which cemented the components together. In an air-spaced achromat, I suspect it is the organic residues (bloom) which gradually form on any glass surface (pollen, tars and compounds from plants etc). My 102mm f13 had this problem a year or so ago. I dismantled the doublet, cleaned it with solvent and then a lens cleaning compound and reassembled the crown and flint components with new spacers which bizarrely improved the resolution cpd with when it was new (thinner spacers I think). To avoid the problem with my 180 Mak, I store it outside in a sealed B&Q storage box with three or four silica gel sachets. Chris

The transparency here last night was good to excellent, so I had another try with my 180 Mak. With the scope and mount in a spot shielded by trees from a distant streetlight and the neighbour's outside light, NGC 5353 itself was fairly obvious with direct vision, as well as NGC 5350. The previous times I'd looked, NGC 5353 was only visible with averted vision. The SN was easily visible as a bright twinkling point at the S end of the galaxy at the point shown in published images, easiest at x100; higher mags made it too faint with DV, although it was still visible with AV - a consequence of the small aperture compared with John's report above I imagine where he found higher mags helped. Interesting that the long axis of the galaxy appeared to be visibly mottled - genuine or an optical artefact I wonder? Compared with a nearby 13.1 mag star GSC 3030-1046 (SkySafari). the SN seemed to me quite a bit fainter, up to nearly a factor of two. As Jupiter had risen above the murk by then (1:00 am), I popped my 102mm f13 frac on the SkyTee and had a quick look; lots of belt detail for the first time this year, but no interesting transits or GRS. Chris

ED80s give lovely views of doubles even if the resolution is a bit limited. I have mine on my SkyTee2 along with the Mak 180 and always start with the little frac. Chris

In a case with desiccant sachets the humidity is very low! Chris

I have found a combination RDF (Rigel) and a RACI fairly indispensable, and in fact I often use my ED80 on the same mount (SkyTee2) co-aligned as well as an extra finder to see fainter objects. To cut the weight of an add-on focuser (which I agree is very helpful) I use a Baader helical focuser - very light, relatively cheap and doesn't extend the fl too much. Comments about storage: I store mine outside mostly in a large B&Q storage box which has a seal around the top, with 3 or 4 silica gel sachets so that the scope is kept dry. That way, the air inside the scope is dry too (important). If you store it inside (humid, warm air) you risk internal fogging (bad for optics) when you take it out into the cold night air. Chris

With the 180 Mak, a 7mm EP is giving x385 - I wonder if this is probably near the limit for the scope (50x per inch of aperture), so the scope optics may predominate over EP optics? Mine certainly starts to run out of steam over x350, although this is sometimes helpful for doubles. Chris