Just got in from a quick study of some doubles in Orion with my 8 inch f/5.9 reflector. I had a 7T6 eyepiece in for most of the time giving a magnification of 171x.
First up was Sirius showing the Pup about 40% of the time as a distinct entity out of the glare of the primary. Encouraged that conditions were beneficial, I moved over to the Trapezium and was pleased to see E and F clear and steady 100% of the time. This observation allowed me to gauge the seeing as 4 out of 5.
Easily split at this magnification were Alinitak [mag: 1.9, 3.7; sep: 2.4"], Eta [mag: 3.6, 4.9; sep: 1.8"], and Meissa [lambda; mag: 3.5, 5.5; sep: 4.5"], which all showed as splendid magnitude contrast doubles with mostly white stars. Sigma was also a fine sight showing the AB 'primary' along with the fainter C and D components.
52 Orionis [mag: 6,6; sep: 1.0"] was clearly resolved (but not split) at this magnification and resembled a snowman with mostly white stars of similar magnitude.
I knew this was a night to try to see the companion of 42 Ori [WDS 05354-0450 DA4AB; mag: 4.6, 7.5; sep: 1.2"]. I was first introduced to 42 Ori in pursuit of data to support Sissy Haas' double star research program. I find this double very challenging for the 8 inch and only resolvable on nights of very good seeing. For this binary I upped the magnification to about 550x using a Pentax 2.5XO along with a Paracorr lens (setting 1).
I was encouraged to see the secondary about 50% of the time in the correct pa using a method of alternating averted and direct vision. The secondary was more or less a light yellow-orange blur vs a distinct orb of light, and probably best described as resolved but not split. Last month I spent considerable time measuring 42Ori with the 15 inch at f/23.5--perhaps I can find a lucky image to post from these studies.
Finally, I managed to star hop over to STT 517AB [WDS 05135+0158; mag: 6.8, 7; sep: 0.7"], a binary I had made note of on my CDSA vol I edition as a good challenge for the XT8i. High magnification (550x) was used here as well to afford a very nice pair of close, evenly matched white star that were 'kissing', that is resovled, but not quite split. I may try to image this one tomorrow night if conditions are favorable.
I think I will head back out now to look at LEO.
Edited by Nucleophile, 22 March 2017 - 10:50 PM.