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Alkaid

Plato Craterlets Re-Visited

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After what feels like months of poor weather, finally got my C8 out last night.   It was a cold crisp evening and cool-down was a little longer than expected, but once acclimatised I spent an enjoyable amount of time hunting down my old friends, the Craterlets.  Plato was fully illuminated (76% waxing gibbous phase) and there was some, but very little shadow relief to help me out.

Craterlet A - seen immediately and easily.

Craterlet B - Seen last.  Had some trouble with this one, but got it in the end.  I feel that I now need a bino-viewer, as this would no doubt help somewhat in the detection process.  

Craterlets C & D - seen after a long period of squinting.  As they are both very close together, they're not too difficult if you put a bit of time in.  

I'm sure you've all seen the link below from a sister forum, but I really like this guide and you may find it very interesting.  Best of luck with the hunt!

https://www.cloudynights.com/topic/34841-guide-to-plato-craterlets/

Edited by Alkaid
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This is a target that I must put more effort into. I have tried a few times in the past and failed to see them but never really seriously spent time looking for them. What eyepiece(s) and magnification did you find the best @Alkaid?

Edited by Geoff Barnes

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Hi Geoff,

I used a Celestron Xcel 9mm which gave x222.  At first I didn't think the seeing would support this, but it just turned out to be the OTA cooldown that was the initial issue.   After cooldown, I was getting good hard views, with a little image shimmer.   I also use a good quality diagonal (TAL).  Have fun with these, they really are great to hunt down.

Out of interest, how are your viewing & seeing conditions in Melbourne?  Do they differ form the UK (lack of jetstream??)  My sister lives in Melbourne, tells me it's a nice place to live.

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Thanks Steve,

Melbourne does get crowned the world's most liveable city quite often, but like any city it has it's good and bad areas.

Seeing conditions are generally more stable here without the jet stream being overhead so often as in the UK. Biggest problem for me is the light pollution from Melbourne which is now a huge city of 5 million people and growing fast. 

I think I will give the Plato craterlets a go with my Baader Morpheus 6.5mm for around 230x next time.

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My favourite eyepiece for spotting the Plato craterlets is the Pentax XW 5mm which gives 318x with my 12 inch dob. My best count was 11. The lunar illumination needs to be favourable so that some shadow is showing on the floor of the craterlets.

 

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I spent some time on them last night with a range of EPs, and found that a 15mm Vixen SLV with my 180 Mak showed them up best. Higher or lower mag made them less visible, given the seeing conditions. I could see the four most prominent ones fairly easily, with hints of several others. As the seeing was passably ok, I popped my ASI220 mono on the scope for a quick pic, which shows the most obvious four.

Nb - as you can see, I'm not a Lunar observer, or an imager.

Chris

 

20_08_03_g3_ap1proc.png

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Looks pretty good to me Chris!

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Hi folks, the key to spotting the plato crater-lets - seeing , transparency and illumination. If the seeing/transparency is not good enough no amount of magnification or aperture will do the job. Obviously high contrast scopes - refractors, mak newts, and some mak cas scopes - make the job easier.

The other night I was using my 15" Dob and turned it onto the moon (instantly blinded!!). At x330 I was able to detect all four cater-lets but the hardest one was the smaller one of the "double". Only in moments of good seeing could I see it.

In the past using an OMC 200 I have detected a 5th crater-let.

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10 hours ago, John said:

My best count was 11

11 is really good going! Dont think I've ever managed more than 4 visually. 

I grabbed an image of Plato last night and can just make out 11, possible 12.  Might make a good reference image when you go craterlet hunting again! 

 

20200206_085926.png

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Here is a link with them labelled. https://www.cloudynights.com/topic/34841-guide-to-plato-craterlets/

Here is another link which gives useful as to the size of a crater visible depending on the scope aperture. http://www.lpl.arizona.edu/~rhill/mincrater.html

Looking at the info - a fifth craterlet is doable with a 8" scope. After that aperture is needed and perfect conditions to get to 11/12 craterlets.

I have always felt I do well if I get to see "the big four"

Mike

 

Edited by Mike JW
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Some fantastic images there folks!  I'm going to try s slightly lower power next time to improve the seeing.

I am captivated by Plato - what seems like a boring flat floor in a smaller scope actually presents some very interesting challenges in a larger one.

Fabulous. 

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Hi folks,

Just come in from messing about with the Dob (15) and thought I would give Plato a serious look. Max useful mag was about x 245. There was no gain beyond this. Conditions were not steady enough to use higher magnification. As per my cloudynights link A,B,C,D, and E, were all easy tonight. With patience and looking in the right area and waiting for a moment of steadiness I manged to positively get f,g and h. At times I would get possible hints of i, j and p but I would not claim them as definite.

A fun time. Mike

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That’s fantastic Mike, wow, all the way to ‘h’ - brilliant. Good stuff!

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