Trapezium stars

[matt c]

Hi all

Just thought I'd start a thread about the trapezium stars, just how many have people managed to see with their scopes. I myself managed to see six very briefly once with a 10" dob I owned at the time.

I think the Trapezium stars are a great challenge and measure of seeing conditions, and know it's rare to be able to see more than six of them.

:)

[Mark at Beaufort]

Matt

I tried for a couple of years to view stars E and F in my 4" APO and 6" Meade frac and always failed. I have good skies but I could only see the main 4 in the Trapezium. Eventually I saw the 6 in my 10" Dob using my Ethos eps. Good test of collimation!!

Here is the original thread.

http://stargazerslounge.com/observing-deep-sky/96349-success-trapezium-last.html

Mark

[perrin6]

6, but after improving my mirrors figure am hoping to see the 7th (magnitude 14.5) although not expecting to as the presence of nebulosity may render it nigh on impossible,

Alan

[James]

I've seen all 6 once or twice with my 10" Newt, 5 have been visible fairly often but more often than not it's only the four that are visible.

One thing I've found is that the F star always seems to be a little bit away from where all the pictures say it should be - perhaps it's an optical effect?

Seeing appears to be the main factor with my scope as I know it's collimated pretty well and has the resolution and light grasp to see them all.

James

[John]

As it happens I was up in the (very) early hours this morning to have my 1st look at Orion this season - and a wonderful sight it was

The conditions were excellent so I was able to scrutinise M42 and the Trapezium carefully with my 4" Vixen refractor and my 6" Intes maksutov-newtonian.

Stars A - D were easy of course with both scopes. With my 4" Vixen, E was visible intermittently, winking on and off with pockets of especially good seeing. I was in no doubt that I was seeing it. F is the tougher one because of the brightness of nearby star C and I suspected I glimpsed it once or twice with the 4" but no more so I'm not claiming the 6 stars with the 4", yet.

With the 6" mak-newtonian, the extra aperture did the trick and all 6 stars were clearly, and steadily, resolved.

The viewing conditions at 3:30 am were excellent which helped a lot of course. The smallest aperture in which I've clearly resolved all 6 was a 5" F/9.4 achromat refractor.

The sight of M42 and it's embedded stars sprawling all over the FoV of my 8mm and 6mm Ethos eyepieces made the lack of sleep well worth while

[Moonshane]

I agree with others that it appears that aperture is definitely required for the six stars to reveal themselves. in good seeing they are relatively straight forward subject to seeing in my 12" even at relatively low magnifications (114x).

not tried with the 6" yet but expect to see all six.

they definitely confirm seeing is good or bad! I saw it with my 15x70s last night but it's still a bit low over the houses for the dobs yet - such a beautiful constellation.

[Doc]

To see 5 is dead easy in the 16" and I have seen 6 maybe 3 times as well. To see 6 the seeing has to be very good indeed.

[wulfrunian]

Saw six with my 10" dob several times last year. They were clear even from my back garden, I was impressed, I hadn't seen them before with my previous 8" SCT.

[Sam]

I've seen all 6 with my 16" Lightbridge. The F star is a real challenge though as the conditions have to be very good. Your scope has to be in tip top condition as well (as in collimated).

[AztecastroMcJ]

i tried imaging them with webcam last week at fairly low power could just get 4,

definetly a good way to test judge seeing, as i read that good seeing is must to see 6.

James

[matt c]

I'm guessing you'd need an observatory class scope to see all the stars, I'm not sure of their magnitude but I bet there down to at least 20 ish. Even then I reckon only the biggest professional scopes can see them without imaging, apparently (I think) they've managed to detected brown dwarfs in the cluster

[gfletcher]

This was my psot of March 2010.

Just been out looking at M42 through my 10" newt.

My aim was to try and see E & F in the trapezium.

When i put the power up to X200 through a 6mm ortho

there they were , clear as day without having to use averted vision

Made my evening as this is the first time i have ever seen them.

My previous C8N scope would not show them

Graham

[A McEwan]

I have seen 7 through our club's 12" Dob, and 6 through my Equinox 120. I've seen 6 through the 8" Dob, but never the 7th - I think it's a bit beyond that scope's capabilities!

[F15Rules]

I've seen the 5th a few times through my 5" Tal refractor, never the 6th. Reading the others posts, it seems that seeing and dark skies are a must.

I hope I can see them all with my new Lomo Maksutove 6", but time will tell..

I owned the 5" frac that Jahmanson saw the 5th star with, and never saw it from my site, so maybe the conditions in my area are not so good as his...or could it be that his eyes are better than mine?? Much more likely, I reckon..

[John]

I owned the 5" frac that Jahmanson saw the 5th star with, and never saw it from my site, so maybe the conditions in my area are not so good as his...or could it be that his eyes are better than mine?? Much more likely, I reckon..

It was an excellent scope I found and very well collimated

You need really tight star images (ie: good collimation) and a dark, transparent sky to pick out the E and F components - they are a lot less bright than the nearby A - D stars and close enough to get lost in their glare under less than good seeing conditions / mis-collimation.

I find good tests of the seeing conditions are i) the ability to resolve 4 components of Sigma Orionis and ii) resolving Rigel's 7th magnitude companion. If I can do these I feel I'm i with a chance to see Trapezium E and F.

[matt c]

I wonder if large refractors ( 6"+ ) out perform reflectors on this?

[Peter Drew]

Saw E & F so easily last week in a NexStar C8se in Tenerife (urban, sea level, not top of Mt. Teide!) that it wasn't a test of the scope but probably due to the good seeing. Not always visible in a 16" at home. Comet Hartley in 10x50's as well.