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Piero

Testing 'E' and 'F' in trapezium - plus other targets

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Thanks MarsG76. :)

Last Thursday, I saw E and F with a Dobson 200mm at 125x which corresponds to an exit pupil of 1.6mm. Both the stars were distinct and clear. Seeing was very good. 

I could not split them in the first hour of observation while the telescope was cooling down, though.

Just a reminder when using medium / high magnifications.

Edited by Piero
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even more strange john, popped the 5mm pentax in and couldnt see them :eek: :eek: , swopped again, and they were there, 200x lovely

I also found that an 8mm EP showed E and F when a 5mm didn't - this was in my 250px, so at x150. 

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I also found that an 8mm EP showed E and F when a 5mm didn't - this was in my 250px, so at x150.

Interestingly a 1.6mm exit pupil again

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Interesting. I struggled with F in my 10" Dob the other day - fleeting glimpses with AV.

Haven't tried in the little Frac, but will give it a go tomorrow night (hopefully). 6mm in the f4.7 Dob and 8mm in the f7.5 frac should do it!

Also. While you have the higher mag eyepieces in, have a scan around the nebula. There is a surprising amount of detail in there!

Paul

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Really interesting thread. Every time I'm here I learn something new! Thanks to everyone who has posted.

I spotted a star just outside the trapezium yesterday, and looking at Piero's map, there's no doubt it was F. I didn't see E though. I'd heard of E and F before last night, but had no idea where either of them were in relation to the main four. Maybe E would have been there if I had known where to look rather than just generally scanning around. It's a good reason to revisit (as if one was needed!).

I used my 10 inch Dob, with stock 10mm eyepiece, for 120x and (I think) a 2.12mm exit pupil. I don't really have enough experience to rate the seeing, but the transparency seemed decent (spotted a mag 11.9 planetary NGC1501 more clearly than last time, M1 was obvious, galaxy Caldwell 7 was there, but galaxy Caldwell 5 went under the radar).

I've used this kit before and not seen E or F, so maybe the seeing was good, or maybe I'm getting marginally less rubbish at spotting things... :-)

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Really interesting thread. Every time I'm here I learn something new! Thanks to everyone who has posted.

I spotted a star just outside the trapezium yesterday, and looking at Piero's map, there's no doubt it was F. I didn't see E though. I'd heard of E and F before last night, but had no idea where either of them were in relation to the main four. Maybe E would have been there if I had known where to look rather than just generally scanning around. It's a good reason to revisit (as if one was needed!).

I used my 10 inch Dob, with stock 10mm eyepiece, for 120x and (I think) a 2.12mm exit pupil. I don't really have enough experience to rate the seeing, but the transparency seemed decent (spotted a mag 11.9 planetary NGC1501 more clearly than last time, M1 was obvious, galaxy Caldwell 7 was there, but galaxy Caldwell 5 went under the radar).

I've used this kit before and not seen E or F, so maybe the seeing was good, or maybe I'm getting marginally less rubbish at spotting things... :-)

I believe that seeing is quite important for this target. Your dobson is fully capable for showing E and F. :) 

I managed to see them with my 8" three times out of three, but the sky was very steady then. 

Perseverance and patience, and you will see them!  :) 

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