Trapezium revisited

[alan potts]

I had about a 2 hour window after dark according to various forecasts which normally speak with forked tongue and I was not let down on that score.

Interestingly I set up the Meade 12 inch with 70mm ED piggyback scope well before the dark fell and was amazed to see the double of Rigel easily through the main 12 inch scope only 10 minutes after the sun had set at a time when you could still read a paper. Only 5 minutes later I could see the Pup which never really gets too far from Dad with the same scope at x90 but 15 minutes later could not even with a power increase.

Seeing was not bad but it also was not the best I have had, even with the split on Sirius under belt for the umpteenth time, though not with this scope, with it now being highest in my sky on good nights I expect it to visible even when dark and it was not. I have always found the Dog star easier in front of the twilight and would suggest anyone wanting to split this double trys this, as it works for me.

Juptier was looking lovely with all moons on the right side in the main scope and on top of the planet in the piggyback scope as I had the diagonal rotated somewhat. There was plenty to see in the main belts but no GRS tonight which really is coming across as red in larger scopes, more so than normal.

Now I turned my attention to Trapezium and the loaded the 3.5mm Delos which I feel is about the correct power at X120 on this smaller apperture, my evening interupted by the hungry cats chorus somewhere over to my left, always sound like babies crying to me. I was rather hoping they did not want to dig up my lawn laying efforts in order to leave calling cards. Viewing the group in the main 12 inch scope at X127 with the 24mm Panoptic it was easy enough to see both E and F, and why not, seeing would have to be fairly bad not to be able to see with a scope of this size, though some nights it is easier than others.

Viewing with the top scope I was starting to think I could see F, a thing that Piero has reported a number of times but was sure that E was not there. The other thing that that was also going through my mind was this seeing or thinking F was there could be defraction rings from the star. I had switched over to the Nagler 6-3mm zoom and found that I only though F was there at higher powers, up to X140 (3mm), around X 100 (4mm) I never saw anything. I was also not sure at 3.5mm either with the Delos. After about 45 minute the weather forecast let me down with a bump by allowing a large lump of cloudy stuff to drift across with nothing in the way of a gap to be seen through the leafless walnut trees.

I really feel that this target with a fairly small scope needs the very best seeing and total darkness to be seen, though I am not too bad on the latter score I don't feel I am getting the breaks needed to crack this. At mag 10.9 both are very close to scope limits to start with and any turbulence from the atmosphere is for sure not going to help any. I don't really believe I saw either E or F but a little part of me thought I may have seen something, the trouble is I am not sure what.

If you have a smaller scope, say sub 80mm give it a try, it would be interesting for site members before Orion goes away for his summer holidays. I have not given up yet!

Alan.

[DRT]

Nice report, Alan.

We  had really clear skies here last night but for one reason or another I never found time to get out. Glad to hear you got some good viewing with those higher powered EPs that tend to spend a lot of time in a box

 

[Piero]

Very interesting report Alan and thanks for taking the time to check the trapezium with your small refractor.

I only used 75x, 103x and 112x for trying to spot E and F. Never seen E. F is a doubt, although I also suspect that chances are I didn't see anything. As you say a perfect seeing and a dark sky could make the trick for these telescopes at the limit of their capabilities.

The diffraction rings cause an issue with these small telescopes. That's why I thought to use mags below 100x, although I know that 120x was ideal with my DOB 200mm. Of course not sure, but 75x under perfect seeing and darkness might be the right trade off? Who knows! Interesting challenge though!

[michael.h.f.wilkinson]

Very nice report. I never tried looking at Sirius in twilight. I should give it a try. I may also try to check out the trapezium with the 80mm some day

[chiltonstar]

I've not seen E or F with my ED80, even under the quite dark skies here. With my 127 Mak, E is seen occasionally, but I've only ever seen F once or twice. The critical factors seem to be good seeing and very sharp focus.

Both E and F were easily visible with direct vision on the three occasions I've looked for them since buying a 180 Mak last December, so clearly (for me) it's simply a question of aperture - having enough photons hitting the retina.

Using one of the many limiting magnitude calculators around, E and F should be visible with a 70mm or 80mm scope if the sky background is dark enough and the scope good enough to focus to a pinpoint, but of course the nebula itself brightens the background sky around the Trapezium and that may prevent a smaller scope seeing them, although there are reports out there of folk seeing both E & F with a 3" frac.

Chris

[laudropb]

Very interesting report Alan. I have tried the trapezium a few times with my 102 frac but have never managed to see either E or F from my back garden. I have see both in my Dob from a dark sky sight, but the LP is too much from home.

[alan potts]

2 hours ago, laudropb said:

Very interesting report Alan. I have tried the trapezium a few times with my 102 frac but have never managed to see either E or F from my back garden. I have see both in my Dob from a dark sky sight, but the LP is too much from home.

Laudropb,

I have managed E and F with my 115mm APO a few times from outside where it is very dark though maybe not as good as it could be, should have seen it the other week in a powercut. I also would have a fair amount of latitude advantage over you, maybe 15 degrees, this will not help your cause as I am sure you know.

[Stu]

Nice report Alan. I've still yet to crack the Pup in any scope I've used. I suspect the Vixen would do it with the right conditions but they never came together for me when I had it.

I've seen E&F in the 100mm Tak surprisingly easily when we had that period of excellent seeing a few weeks back. It showed me just what that scope is capable of in the right conditions. I can see that an 80mm would do it under better conditions.

[alan potts]

Stu,

You should try it before dark, it really makes a difference as it takes all the Pink Floyd light show out of the main star. I actually slewed to it in daylight as the scope with never being moved is always aligned so to speak. I tried for Mercury as well but it was telling me I needed to move the hill, another night. Gave your old 5mm Hutech ortho a good try as well but E and F are made of tuffer stuff and didn't succumb

Alan.

[Stu]

Will give that a go Alan. I have a goto mount now so will try leaving it aligned for a few nights to pick it up earlier.

[alan potts]

Stu,

It may be worth noting I am using a fairly large 12 inch Meade but I have done it with smaller. The interesting thing is it is only recent I have even seen the Pup with the Meade after about 8 years of failure. My best scope for it is the 115mm APO and it is not difficult with the Sumerian. The trouble with Sirius is once it is scintillating it becomes very difficult to even see a point source of light of any kind.

Good luck and let us know how you faired.

Alan

[Stu]

42 minutes ago, alan potts said:

Stu,

It may be worth noting I am using a fairly large 12 inch Meade but I have done it with smaller. The interesting thing is it is only recent I have even seen the Pup with the Meade after about 8 years of failure. My best scope for it is the 115mm APO and it is not difficult with the Sumerian. The trouble with Sirius is once it is scintillating it becomes very difficult to even see a point source of light of any kind.

Good luck and let us know how you faired.

Alan

Thanks Alan. Well given my minimalist approach currently I only have the Tak and the PortaBall to play with. I wonder if the mirror quality and curved vanes on the PB might help with it?

[John]

Nice report Alan

I'm sure I've posted this before but I find F quite regularly with my 102 Vixen but it has to be a rather good night to see E. Both pop out with the ED120 without too much pursuasion although knowing where and what to look for helps a lot. On a goos night with the 12" dob, well they can't be missed really.

SO I've seen them, I've not "got the T-shirt" but they can be bought if required :

http://www.zazzle.co.uk/hubble_orion_nebula_trapezium_stars_t_shirts-235866547819562908

 

[alan potts]

John,

I really think the pink is a must have fashion item, nice with a black jacket.

[Special K]

Nice challenge Alan, and I'll take you up on it!  I've tried for E and F with the ED80 before but not been confident of a spotting.  Have had a few doubts at the EP though, so worth another try  

Glad you got a break in the weather.

[Special K]

On 29 March 2016 at 08:54, chiltonstar said:

 

Using one of the many limiting magnitude calculators around, E and F should be visible with a 70mm or 80mm scope if the sky background is dark enough and the scope good enough to focus to a pinpoint, but of course the nebula itself brightens the background sky around the Trapezium and that may prevent a smaller scope seeing them, although there are reports out there of folk seeing both E & F with a 3" frac.

Chris

I reckon you've got a good point about the nebula brightening the background...........ironically, we always want a bright neb but not in this case!  Perhaps a very high mag will knock out the surface brightness enough. I'll give 185x a try next chance.