E but no F in the trap.. is that perfectly normal?

[Fozzie]

Evening all.. just spending my time observing m42 at 112x in the 4".. for the first time I can 100% see E in the trapezium but can't for the life of bag F.. is that right... can it happen.. or are my eyes playing tricks with both E and F.

Ta

Fozzie 

[John]

E is easier to see than F. F is a bit fainter than E and closer to a brighter star which makes it more difficult to pick up. With a 4" scope I've found that I can see both with my 4" refractor under good conditions but not all the time by any means. I would not call either really easy with a 4" scope so I think you have done quite well to pick out E.

You could try playing with different magnifications to see if you can tease out the F star.

 

[Fozzie]

Thanks John... quite pleased I've got one of them.. unfortunately the 112x is as high as I can.. only brought a 17.3mm and 10mm out with me... can even make out the rift between m42 and m43.. which is a first in the 4".. no complaints here..

Ta

Fozzie 

[mikeDnight]

1 hour ago, Fozzie said:

Evening all.. just spending my time observing m42 at 112x in the 4".. for the first time I can 100% see E in the trapezium but can't for the life of bag F.. is that right... can it happen.. or are my eyes playing tricks with both E and F.

Ta

Fozzie 

I think seeing the E & F stars has a lot to do with steady seeing and not so much with magnification. It's easy to wash them out by using too high a magnification on an average night. I wasn't able to make out either with certainty tonight as the seeing was a bit blurry, possibly because of ice crystals in the atmosphere. I've found them obvious but never easy on good planetary nights ie steady nights that have a light mist. Plucking the E star out of the trapezium certainly gives you confidence in your beautiful 4" scope and also in your skill as an observer. 

Mike

[DRT]

Glad to hear you got some clear sky

I found this interesting image here...

E & F are both mag 11 stars but F is close to the brightest star in the Trapezium so it might be more difficult to pick out when the seeing is marginal?

[Fozzie]

Thanks gents for the affirmation, nice to know I'm not hallucinating.. The E was there in those fleeting moments of good seeing, faint but detectable exactly where Derek's image puts it... I think transparency must be favourable too as I'm fairly sure more of the nebula popped out at me tonight.. Quite a lovely sight.. Oh well I have to grab the F another time.

17 minutes ago, mikeDnight said:

Plucking the E star out of the trapezium certainly gives you confidence in your beautiful 4" scope and also in your skill as an observer. 

Mike

Thanks Mike, nice compliment  .. My last few outings have been imaging the moon really so I've not done much visual for a few weeks.. Enjoyed tonight with just spending a good hour n half on the same target.. I've also just tried some bins for 20mins or so.. Only 8x40.. But a few nice open clusters, I can see the attraction of them..

ta

fozzie

 

[DRT]

Your post persuaded me to brave the cold and set-up my Evo 150 F8 for a quick look at the Trapezium - in shorts, sandels and a t-shirt

I managed to stay out for 20 minutes to get some sort of dark adaption and through my Ethos 6mm (x200) I could fleetingly and intermittently make out E but no sign of F. More mag just made the whole view look like a wobbly jelly.

 

[Fozzie]

I can be very persuasive when I want to be you know... sounds similar to me Derek, I tried a somar image yesterday morning, nearly 3000 frames, 2500 in an avi and PiPP gave me 1 back.. the seeing is not good, hence why I took only the 10mm out for 112x.. I was getting the E only in the fleeting stability moments.. but glad you caught it to.. 

What was shaking more at 200x in shorts and t shirt... the seeing or you teeth.. hard core 20 mins that!

Ta

Fozzie 

[chiltonstar]

Interesting observations! I've found with that smaller scopes (4" LF 'frac, or 127 Mak)  I can see F more easily than E, and that good seeing and transparency are necessary to see E.

With my 180 Mak, both are much easier to spot, but good/excellent seeing is still necessary to see them both clearly. At x70, both can be seen, but they are easier at x270 with a 10mm Ortho.

Chris

[Scooot]

I managed to get out in the very early hours of Tuesday morning looking at Orion with my 16". I could only just make out the e star and even then it kept coming and going. On other occasions both e & f are quite clear. 

[alan potts]

Fozzie,

I may well have the letters mixed as I tend to agree with Chris above. I find that one, shall we say is easier than the other and as Mike pointed out steady seeing is a must have. I tried them last night though they were not best placed and it was very windy. I dodn't manage either of them and got cold into the bargain, I do find though that your X112 is about ideal for them, give it time.

Alan

[niallk]

I've only recently seen E and F for the first time, and that was with my 15". I never saw them in my 10" ... Must go back and look again now that I 'know' what to look for.

The pic from DRT below is very good in showing the challenges of F when seeing is a bit wobbly!

I looked another night and couldn't catch F in the 15" for example - transparency and seeing just weren't as good.

8 hours ago, DRT said:

Glad to hear you got some clear sky

I found this interesting image here...

E & F are both mag 11 stars but F is close to the brightest star in the Trapezium so it might be more difficult to pick out when the seeing is marginal?

[YKSE]

My experience is more in line with Chris, i.e. F near the bright C is slightly easily seen in around 120x (120ED or C8) to me, it looks like a bulge of the  bright C.very good seeing is needed though.

[Stu]

SkySafari has F marginally brighter than E (10.2 vs 10.3), basically visually identical. I am with the E crowd in that I find E easier than F.

They are both highly seeing dependent (plus cooling/collimation but that's a given really) Seeing has been pretty bad here lately, I was using the Vixen 102mm f9 Fluorite the other night and was struggling to us any mag at all. E was fleetingly visible but no sign of F.

I guess visual acuity comes into play with this sort of target too?

[Fozzie]

I know the seeing over the over the uk is bobbins at the moment, and I was being opportunistic by going out, but I was initially trying out a pair of bins my good lady bought for Christmas whilst the scope cooled.. To be honest I had no plan, just wanted to look at "something" and Orion is well placed for me at the moment.. I've also an astronomik uhc I wanted to give a go with as I've had my doubts that is a dud...

anyway transparency seemed very good, lots more of the neb in the 17.3mm and 10mm than I've seen before, with the 4", and without the uhc filter the E.. Defo the E (see below) just blinked in and out with the 10mm.  I had been observing the neb for a good hour by this time and there were moments of steady seeing, fleeting as they were but it was here when I caught it.. Faint but there.

I'll be giving this another crack as soon as, now I've got what I'm looking for and what to expect.. 

Btw the double cluster in a pair of 8x40 is a lovely sight!!

Ta

fozzie

[Fozzie]

Didn't realise this was such a divisive issue lol... Is like marmite, either your in or your not... 

[alan potts]

1 hour ago, niallk said:

I've only recently seen E and F for the first time, and that was with my 15". I never saw them in my 10" ... Must go back and look again now that I 'know' what to look for.

The pic from DRT below is very good in showing the challenges of F when seeing is a bit wobbly!

I looked another night and couldn't catch F in the 15" for example - transparency and seeing just weren't as good.

Niallk,

With decent conditions they should be easy with a 10 inch.

Alan

[rockystar]

I've had a couple of goes of the trapezium in the last week. Last night i was out at a dark site, the nebula was lovely showing some nice expanse to the tendrils, but only 4 stars, last Thursday (I think) from my garden, the nebula wasn't as extended but I managed the E star for the first time, no sign of the F though, and the E was a bit tricky but it was there.

This was in my 8" dob

[YKSE]

Just to add a minor point, using eyepiece with less scatter (ortho .e.g) on these kind of uneven brightness close stars has a little advantage too, the fainter ones are easily swamped by the scatter light from bright ones. An inexpensive 10mm BCO e.g. in a 8"f6 dob will mostly likeöy beat most of of wide field EPs.

[Peter Drew]

As already mentioned, seeing is probably the most important of the several factors. Here in the UK I quite often find E & F invisible in a 16" leading me to believe a large aperture is unnecessary or for that matter high magnification. By contrast, with my C8 in Tenerife they are no test of aperture or good eyesight. I've still yet to see them with my 90mm Mak despite its textbook star images.  

[wookie1965]

I have only ever seen E and F once in my 6 inch scope, when I get my mount back going try to see them in both my 8 inch newt and 4 inch Frac. 

[spike95609]

I've never seen F in my 10". I couldn't see E the other night as the seeing wasn't great, nor was it entirely brilliant last night, but it was better and I could definitely see that E was there. No amount of staring or swapping EPs was bringing F out though.

[Peter Drew]

Last night I was using a 16" SCT and a good 20" Dobsonian (you know, the type with a Newt on a Dob mount. ). You would think that E & F would be easy but I could not see them in either telescope initially. As Orion rose and conditions improved  I spotted them first in the SCT and later in the Dob. This demonstrates that aperture is not necessarily "king" for this observation. When conditions are excellent, rendering them to be seen easily, it's surprising how small yet intense these points of light are compared to the nearby brighter stars.

[John]

My 12" dob usually shows E & F routinely and obviously at arounc 200x. Not last night though - stars were very fuzzy at any sort of high powers

Even the transparency of the sky was not as good as it at first seemed, once you put the scope on DSO's.

I gave up with the scope eventually and spent a less frustrating half an hour or so with 11x70 binoculars - the best instrument last night !

[alan potts]

I remember reading somewhere that both can be done with a fairly small apperture, I seem to recall 60mm being mentioned. That set me off trying to split the two with my 70mm ED, which gives a tidy sharp star. After many attempts over a period of about three weeks I concluded I can't do it with 70mm from my location which as many of you know sits Orion a fair bit higher in the sky. I have done it many times with the 115mm APO though. I wanted to have a hunt for G and H with the 18 inch but many articles tend to suggest this is wishful thinking and that some where near 36 inch would be needed.

Alan