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Old 19-10-2014, 08:55 AM
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michael_m is offline
Join Date: Jul 2014
Location: Melbourne
Posts: 11
Two very different observing sessions in the last week

October 12 - Heidelberg, Vic
10" dob, 32mm superview, 15mm plossl

I had a clear night (until the cloud rolled in just after 10) and thought I would attempt to find my way around Sagittarius with a printed star map, rather than Stellarium for a change. I used the Deep Sky Hunter atlas from One reason for this is that although the light from the screen when using Stellarium doesn't hurt my night vision in my light-polluted backyard, when I go to my parents in Sth Gippsland it feels like having a street light next to me. A paper map and dim torch would be more preferable. So I thought I'd get in some practice.

Light pollution to the west from my place is appalling - the light dome from the city is apparent, the sun was still influencing the sky and my neighbours had their lights on. My wife also needed to be in the kitchen for a while, so my lights were shining as well. In spite of all that, I had little problem finding my targets.

I started with looking for M4, but in the circumstances it was too dim for the entire session. I have seen it from my backyard before, but that was when Scorpius was in the east. Then a quick getting my eye in on the False Comet Cluster and then Ptolemy's Cluster (two of my favourite objects to look at), I went for my first new target of the night, M69.

Well, using the star map was a bit different from Stellarium. For starters, everything is oriented for a norther hemisphere observer (in direction of text for instance), and it took me a bit to separate the size of the dot from the size of the star in the scope). And on Stellarium I have developed the habit of zooming in until my screen approximates the FOV of my spotting scope, to help home in on the object. None of that here though.

But within about 2 minutes, there was M69. Fair enough. The excitement of finding it was not matched by its visual splendour. I only explored it at 83x for a minute or so, before heading to M70, which was a straightforward walk from there. Again, at 83x, not hugely impressive, but observational viewing was not the order of the day.

Then, I thought I would try for M22, which I always like and have found many times these last few months. While I don't need a star map to find it anymore, I tried to use the map to locate it and started to run into trouble. I just couldn't match what I was seeing to what was drawn. Eventually (by twisting my head, then the paper) I tallied what I was seeing with what was drawn, and after 10 minutes I found in the scope what was taking me 5 seconds to find in binoculars.

And that was what was causing me the most grief - I could always match Stellarium views to my binocular views (and then to the spotting scope views), but I couldn't reconcile the binoculars with the star chart all the time. But I was improving!

M28 only took me another couple of minutes to bring up in the scope (most of that in looking at the chart, seeing if what I had in the finder was the same thing, and repeat), and compared very favourably to M69 and M70. Definitely one I will need to look for again.

Flushed with success, I thought I would try to find M54. And there I ran into a mental roadblock. When I look at Sagittarius, I "see" the teapot and teaspoon, and use that as my mental roadmap to orient myself in the constellation. Well, the star chart had a different set of constellation lines drawn on it and for the life of me I couldn't see the teapot on the chart and had absolutely no idea where to start in the sky. I just couldn't reconcile the two . After about 20 minutes or so of fruitless endeavour (yes, it really was that long - I was literally incapable of working out how the sky and the chart now fit together), I gave up in disgust and when free-ranging for some other objects in different parts of the sky to give myself a break.

So, I took a break firstly with 47 Tuc and spent a nice 5 minutes or so just losing myself in it, then swung around to Diphda and starhopped using the double triangle asterisms to the Silver Coin Galaxy, where if I stared long enough and was generous enough with my interpretation, I started to think I might be able to see a bit of central bulge?

Feeling refreshed and with renewed confidence, I swung back to Sagittarius and lo-and-behold, the teapot came to me in a vision on the paper! It was a total gestalt. Now the sky and the chart matched, and it only took me another 2-3 minutes to find M54. For good measure, I then star-hopped using the chart back to M70 then M69. And that was it - the clouds came in, and I went inside.

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