chiltonstar

21 hours ago, John said:

There are a couple of interesting dark patches in the ejecta from Copernicus. Copernicus H lies in the centre of one of them. It looked like a tiny bright edged pit surrounded by a darker halo of material last night. Not sure what the other one is called. I've arrowed them on this image by Andre van den Hoeven. They both stood out well under last nights illumination. At one point they were thought to be of volcanic origin but Lunar Orbiter images have showed that at least H is definitely of impact origin:

 

 

 

 

 

The dark areas are interesting - in my image below you can see others as well, although I can't see these visually. I have always assumed (but I know very little about the subject) that they are caused by fine dust settling on a darker substrate, and that an impact removes the dust immediately round the pit.

Chris

Some brilliant views last night - best for me at x190 with a 180 Mak. Schickard was amazing, but even Copernicus was showing a lot of detail in the escarpments.

Chris

A wealth of fine detail!

Chris

Clavius last night with a 180 Mak. Good seeing generally, but with some heat plume effects from a neighbours house. 1000 out of 5000 frames, processed in AS, PS and Topaz AI. More craterlet detail than will be reproduced I imagine.

Chris

Some nice targets - all we need now are clear skies!

Chris

21 hours ago, John said:

I've tried a couple of times with my 12 inch scope but with no joy at all so far

There is no harm in trying though

Indeed not - always an interesting challenge, even for those of us with small scopes which are not capable of splitting the pair!

I noticed last night that Procyon was barely twinkling, so I got my 180 Mak out and had a look to see what it actually looked like. The seeing was excellent++, so there was a stable diffraction pattern visible even at x450, with 5 rings or so as though some celestial arachnid had been at work . As the scope cooled, there were three radial bright zones which gave artefacts on the outer diff rings which looked like secondaries and could have been mistaken for them except for the fact there were three of them and they were symmetrical at 120 degrees. These disappeared after 10 minutes leaving just one bright spot at ca. PA 270 degrees which clearly wasn't Procyon B as the PA was wrong, but presumably caused by a smear on the optics or whatever. I can see how folk with small scopes often report having seen Procyon B even when it isn't technically possible.

Chris

Imaged last night (30th March 2021, 22.30 UT) with a 180 Mak/AS1220 mono camera. Image processed in Autostackert and PS. Best 20% of 5000 frames.

Chris

Just had my 102mm Vixen objective f13 'frac out for a brief spell between clouds - brief, but glorious! As with the Scopetech above, no visible CA. I also found Bailly, I think for the first time.

Chris

I finally got to have a look at it last night. Excellent seeing, no wind, a little haze and not too cold, so generally good!

At x200 and x300 the feature was exquisitely sharp and defined (more contrast at x200), with the added feature of the little pin sharp craterlet in the centre of the main crater next door. Although the lighting conditions were past optimum to show Hesiodus at its best, still well worth a look - thanks John for the heads up.

Chris

No 81 I believe......

Chris

One to try for! Clear here last night until I started to set up, then thick murk. Still, "tomorrow is another day" if I remember the quote correctly......

Chris

Some lovely pairs there! Interesting that you see Izar B as white - I tend to see it as "electric blue". Must be an aperture thing I suppose.

Chris

Algieba is a superb pair indeed, with an amazing gold colour.

As Stu says, you get diffraction rings as well - you should see sharp diffraction rings around a bright star if your scope is fairly decent optically, and in focus. Difficult with some scope designs I believe which can be a bit mushy. The size of the Airy disk, and the brightness of the diffraction rings around can set practical limits to resolution of double stars.

This is an example ring pattern.

Chris

I had a look last night as I had clear sky to the N and W before cloud took over again. Scope was a 180 Mak with a Hyperflex 7.2 to 21.5 mm zoom EP.

Immediately after setting up, the B component was a fuzzy ball in the right position, well clear of the A component. After 10 mins scope equilibration, the fuzzy ball shrank to a diamond point - a very pretty pair. Seeing was good or better, with nearly complete stable diffraction rings for most of the time. The C and D components were very obvious (orientation in the Mak is the same as in the sketch by John Nansen in John's post above.

As the conditions were good and the cloud hadn't yet arrived, I had a look at nearby Struve 799 which is a very close double (0.8 arcsec) - very pretty although faint (mags 7.3, 8.3) with a PA of 162 degrees. Challenging, but certainly split. Another pretty pair I took in nearby is 41 Aurigae, which is a balanced pair with a separation of 7.3 arcsec - looks a bit like a fainter Castor, which is also nearby and glorious.

Chris

Our cats have usually helped with my observing, sitting alongside my chair and protecting me from attack by any mice etc, even at -2 degrees. There was that clip a year or so ago showing a cat fending off the attack by a dog on a small child - proved it for me that cats are really mans best friend, despite what doggy owners say....

Chris

Good stuff - sub arcsec can be a challenge unless the seeing is excellent!

I'm still waiting for someone to come up with a triple-triple!

Chris

Good seeing here, but haze plus Moon wiped out all but the brightest stars. Good to see Vega rising in the NE, even if it was twinkling madly. Mr and Mrs Fox seemed to be enjoying the nearly full Moon, or maybe it was one of my neighbour's hens.

Chris

On 26/01/2021 at 05:49, NGC 1502 said:

I just love triples, at my last session I viewed 3 triples, Iota Cass, Beta Mon and Zeta Cancer Tegmine. I usualy struggle to manually find Tegmine and such was the case this time.  Castor & Pollux point almost directly at it so sweeping the area at low power works best for me.  Cracking sight at high power 👍

Ed.

...and of course Castor is itself a triple, one of the most spectacular in some ways.

Chris

There probably isn't a sufficiently good word to describe the view that you sometimes get on those magical evenings when the sky is clear, the air is still and the mozzies have gone to bed. Several years ago, I watched Saturn for nearly an hour through my 180 Mak as it was one of those evenings, with Hubble-like detail and stunning soft banded peach colours of the disk. That's why we all continue with this hobby, despite the long cloudy periods and the neighbour's security lights!

Chris

The best view I've found with my 180 Mak for looking at DSOs is with the 38mm Panaview 70 degree FoV eyepiece. If there is vignetting, it's certainly not obvious to me and the view is glorious. The eye relief is not the best, but certainly ok. 

Chris

I tried a few doubles in Orion, but the seeing here was barely average, at least to the W. Transparency was pretty good though, so I spent some time on M1 before the -5 degrees got to me. The elongated shape with a hump in the middle was fairly obvious at x70 (180 Mak) but more detail eluded me last night because of the relatively light sky. When it's higher in the sky I often see a bit more detail. The joy though of having a clear night........

Chris

19 minutes ago, Alan White said:

@alex_stars Neigh, it cannot be stabled, far to big.... or have you a very large stable 😉

 

Oh I dunno, I had a Mars in a stable once.

Chris

This is of course true, but I don't think you can beat the laws of physics - agreeing with @Vlaiv in an earlier post. Coming back to the original theme, for much of the recent Mars season, I had my 4" f13 (Vixen objective) frac out alongside my 180 Mak and there was a consistent benefit in using the larger scope on nights with good to excellent seeing. On poor nights, the frac gave a better (more contrasty) view but when the seeing was good enough,  extra detail was apparent with the Mak even though the contrast was slightly less.

When I bought the Mak it was after using a long focus frac for nearly 30 years - I wanted a larger frac but couldn't afford (or lift) it and the Mak seemed the next best thing. I haven't regretted the decision, and have not been limited by the cooling problems that some describe - every scope type is a compromise and in the real world you have to seek solutions to mitigate problems. You can reduce dT/dt issues with cladding and storage at ambient temperatures for example.

Chris

Some interesting comments on OOUK, and certainly the first horror story has been seen on this forum before. Was there ever a reply from them giving their side of what happened? If at all true, it will not exactly encourage sales I would have thought, so an explanation or a denial would seem to be in order?

Chris

1 minute ago, John said:

I don't use Sky Safari but I will have to give the Cambridge Atlas another chance.

I do have Sky Safari Pro but I don't use a mobile device out with me when I'm observing.

 

I have a large tablet with SS6 Pro on it - I use it inside a darkened electronic component bag to cut the brightness further.

Chris