John

Thanks for all the feedback folks.

Frankly, these are the best lunar views I've ever had

The seeing is still steady and the misty clouds have thinned a lot so very high magnifications are bearing fruit again. 795x on Gassendi - I've never seen so much detail

This is a LRO image but what I'm seeing is very similar even at that magnification:

Having a good look at a number of lunar domes as well. A feature that I have not paid a lot of attention too in the past but once you realise that they are quite subtle features, there are plenty of nice ones to find around the Mare Insularum. Some have nice little (well, 2km diameter) central pits as well.

The cloud has thinned quite a bit here so lunar observing is still going on.

Can't see too many stars though.

Got a look earlier (pre-clouds ) with my 12 inch dobsonian. I thought the nova might be a little bit brighter ?. Only a wee bit - maybe mag 7.5 ??

Superb here up until about 30 minutes ago when the cloud thickened up considerably blotting things out. I can see the moon through it but resolution is very limited now. Earlier it was truly wonderful. Gassendi was, as you say Paul, a real show stopper !

Doh ! - very thin and wispy clouds have thickened up so I can just about see the Moon and nothing else.

I'll give it some time to see if things clear up again.

Sirius split was the best I've had for ages. Could do with some more of that !

If you can, get out and observe the Moon

I've just had a short session before supper with my 12 inch dobsonian and the seeing conditions seem to be outstanding currently.

I've been observing the concentric crater Hesiodus A again, which I reported on last night:

https://stargazerslounge.com/topic/374414-more-unforecast-clear-skies/

The image was so sharp that I just kept piling on the magnification as my jaw dropped. Eventually I was using the 2mm (!!!) setting of the Nagler zoom for 795x and the crater looked stunning.

Gassendi, it's rilles plus the central peaks are also really spectacular !

Also picked up the more challenging concentric crater Marth. The crater itself is 7 km in diameter and the interior ring probably 3-4km so very small targets so the high magnifications that seem to be working just now helped a lot.

I don't know how long it will remain clear and steady here but I'm enjoying it while it lasts

A good evening for spotting Plato craterlets and the rille on the floor of the Valles Alpes I think.

Is that a single element Steve ?

The ED100 has an air spaced doublet objective doesn't it ?

2 hours ago, Fozzie said:

here's an updated list to accompany the map on the original thread..  the moon wiki has changed to the moon.us wiki

https://the-moon.us/wiki/Concentric_crater

Thanks Fozzie

I'm finding the theories on the formation of these little craters fascinating to read about.

I'm hoping to have a look at Marth (#27 on Wood's list) this evening if it stays clear. It should be on show tonight.

The Ramsden Rilles are nearby and sound interesting as well

45 minutes ago, Saganite said:

It turns out that there are lots of them to find Chris, and it has made me realize that whilst lunar 'observing' I should actually do some work instead of swanning around low flying over the surface just for the thrill of it.....

Whats that old saying ?: "All work and no play makes Jack a dull boy"

It's great when the illumination allows the craterlets to show as actual pits with tiny ramparts

You can see the "big 4" generally under more direct illumination as white spots but the smaller ones are very hard to spot that way. A bit of shadow is very helpful with those. Good guide to them in this CN post from David Knisely:

https://www.cloudynights.com/topic/34841-guide-to-plato-craterlets/?p=450105

I've just found that we have discussed concentric craters before on SGL. Here is an interesting thread started by @Fozzie:

https://stargazerslounge.com/topic/265608-concentric-craters-–-a-relatively-rare-lunar-feature/

When I next get a chance I'm going to try and find another one of these, Marth:

https://en.wikipedia.org/wiki/Marth_(lunar_crater)

11 minutes ago, Stu said:

Thanks again John. Managed to see Hesiodus with its centre ring, very unusual and great to see; I had not heard of it before, so thanks for the pointer.

Glad you saw it Stu

Went for the 130mm triplet tonight. Got a good couple of hours in before the clouds stopped play:

9 minutes ago, Saganite said:

Had a look at Crater Hesiodus this evening after you pointed it out, never seen it before so thanks for that John.  

It's rather neat isn't it Steve ?

I think it's one of the best of these concentric craters to observe. Interesting little Sky & Telescope piece on these here:

https://skyandtelescope.org/observing/celestial-objects-to-watch/crazy-about-concentric-craters02252015/

The theories on their formation are quite varied.

I'll have a go at the other two mentioned in the above link sometime.

It's rather clouded over now so I'm having a coffee break.

Not looking too good from where the weather is coming from so that might be it for tonight

Just had a look tonight at the nova. This time with a 130mm refractor. Brightness compared to nearby stars seems to be the same to my eye as it was last night.

Lunar highlight so far is this little fella, the 14km diameter Hesiodus A, on the shore of the Mare Nubuim. Last night it was shadow filled so the neat inner "doughnut" was not visible but tonight, all is revealed

"Clear Outside" gave me cloud cover all night but it's quite clear at the moment

The seeing is a bit more variable than last night, good one moment and not the next. Slightly annoying gusts of wind now and then as well. I've managed to see the Pup star with the 130mm refractor on and off though.

The moon is looking very nice again, sharp and steady at 400x with the big refractor. Some lovely detail along the terminator.

I'll have another look at the Nova Cas 2021 later, if it stays clear.

Have fun if you are out

There should be a couple of screws holding your 1.25 inch eyepiece adapter into the focuser drawtube but I can't see those on your scope. The arrangement should look like this:

By loosening the lower pair of chrome screws in the photo above, the 1.25 inch eyepiece adapter can be removed and a 2 inch eyepiece adapter inserted. The 2 inch adapter looks like this:

I wonder if your focuser drawtube has been modified in some way as it does not have that lower pair of screws

3 hours ago, F15Rules said:

I really like that wooden tripod John..is it branded or a vintage?😊

Dave

It's the same or similar to the ones marketed under the Oberwerk branding to carry big binoculars Dave. I got it from the Astroboot. It's not quite as sturdy as a Berlebach Uni but pretty close and a few kg lighter.

2 hours ago, 7170 said:

I've just measured it at mag 7.8 (just using ASTAP - so will have to do better later), what are others measuring it as now out of interest?

I'll go with mag 7.8 as well. It seems to have been stable at that for the past 3 nights.

Great report Stu

17 minutes ago, paulastro said:

That was a great report John, I really enjoyed reading it. Pleased you had such a good session.  I had, unexpectedly, some clear sky from 6.45pm to 7.30pm. I spent much of the time watching the sunrise over Copernicus 🙂.

Thanks Paul - I've really enjoyed tonight and I'm glad you have had some fun as well 

I'm loosing my clearer patches now with more and more clouds starting too intrude so I'll be bringing things to a conclusion shortly.

I've just been looking at Gamma Leonis at 450x (which is a bit nuts ) - amazingly well defined airy disks with a very fine single diffraction ring around each star. Rather lovely. I could have done with some more nights like this when Mars was at opposition.

Here is another of my setup tonight. I have to hand it to my old Skytee II on the Oberwerk-type wooden tripod - I've been using up to 450x at times for lunar observing tonight in the excellent seeing conditions and my F/9 100mm refractor has been held really steadily by this mount / tripod combo. A sharp rap on the end of the scope tube results in a quick shimmy of the image which settles back to completely steady in less than a second. For a rig that is light enough for me to carry easily in one piece all around the garden, this is pretty good performance I reckon

Really excellent seeing conditions tonight allowed "silly" magnifications (ie: 300x plus) to be used even with my 100mm refractor. The moon is looking serene at 62% illumination.

So many wonderful targets to enjoy tonight. I'll just mention here highlights in and around the Mare Nubium:

- The Rupes Recta (AKA the "Straight Wall") and nearby the delicate Rimae Birt. At high magnifications the "wall" really is not that "straight" !

- Crater Alpetragius with it's bulbous interior mass - some say it looks like a giant egg set in the craters floor. To me it resembles a huge hi fi base speaker cone too

- Crater Arzachel which seems to bring together a range of classic lunar crater features in one place - finely terraced walls, a distinctive central peak complex, floor craters and a curving rille for good measure.

- Crater Davy sitting on the edge of the of the indistinct but much larger Davy Y but most interesting of all the remarkable crater chain known as Catena Davy. a chain of 23 small craters in a straight line that run right across Davy Y and out over it's crumbled rim. Thought to have been formed by a multiple impact event where the impacting body broke up before hitting the surface.

- The long straight "highway" of the Hesiodus Rille that runs for 300 km across the lunar surface.

- Crater Pitatus with rilles along the foot of it's walls on two sides.

- The immense and ruined crater Deslandres with Hell (crater) on one side and another fine Catena (crater chain) comprising of 5 craters gradually diminishing in diameter on the opposite side.

And so much more besides !

How's this for a great view of Catena Davy snapped by the Lunar Reconnaissance Orbiter and then projected onto the lunar surface in Google Earth