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My tale of Trapezium F - finally

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#1 stratocaster

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Posted 28 September 2012 - 05:15 AM

I've been back into the hobby solidly for the last year. I have an SV102ED and a Zhumell 10" dob. The standard mirror on the dob wasn't much good for planetary and splitting doubles. I couldn't even make out the E star with the dob. The E was not obvious with the SV102, but I could make it out. But I could not detect the F star with either scope to save my life - even on nights that appeared to have fairly good seeing.

I've since replaced the stock mirror with a Zambuto. I'm still getting my legs with it a bit and am going thru many old favorites to see if there's anything new I can make out with my new mirror.

Seeing was supposed to be very good tonight, so I was looking forward to see how the Zambuto would do on planetary. I waited for Jupiter to come up. It was glorious at 400x when the seeing steadied. Spent a couple hours looking at it. I started to pack up around 2 am and realized Orion was coming up. So I thought I'd check out the nebula.

The nebula was still very low - maybe 20 degrees above the horizon, but I swung the scope over at low power and checked it out. Even without a filter there appeared to be much more nebulosity than I remember - love that Zambuto. Beautiful. Ah yes, the trapezium! Could I see the F star?!

I put in a 7mm Pentax XW and took a look. When I think of all the times I tried to see the F star and failed, and here it was as easy as pie - at 20 degrees above the horizon. Wonderful. Seeing stars A-F is really a beautiful thing.

Now, maybe the skies were just particularly steady, or the Zambuto is just a way better mirror than the stock mirror, or both. But it was almost funny how easy I could see A-F.

I've seen many posts here how the F star has been seen with 80mm - 100mm scopes. Wow. Maybe one of these days I'll be able to pick it up with my refractor.

#2 tomharri

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Posted 28 September 2012 - 07:42 AM

Quality optics make all the difference, welcome to the Zambuto club!!!

#3 Rich (RLTYS)

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Posted 28 September 2012 - 08:31 AM

Resolveing the E and F components depends a lot on the seeing conditions. With my 10" Dob sometimes the two stars are easy other times they are difficult.

Rich (RLTYS)

#4 RAKing

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Posted 28 September 2012 - 10:52 AM

Quality optics + good seeing = priceless! :cool:

Don't get too wrapped up in why it happened, just enjoy the fact that it did happen.

I love quality optics and have a lot of money invested in Zambuto and Russian mirrors, plus the finest American refracting lenses. But it's those nights when the jet stream leaves me alone that spending all that money is worthwhile.

Congrats!

Ron

#5 Rutilus

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Posted 28 September 2012 - 02:15 PM

Seeing the F star with an 80mm is really very, very good indeed. I've lost count of the hours I've spent observing
this object with my Tak 102mm APO. Only on nights when the seeing plays ball, do I manage to spot it.
With my cheap as chips 150mm f/8 Chinese Achro (which cost me less than the 7x50 Tak finder) I always see both E and F.
It has to be really bad seeing for me not to pick-up F in my large Achro.

#6 Bonco

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Posted 28 September 2012 - 02:45 PM

E and F are frequently viewable in my Original Zhumell 10". I've viewed them several times with my 4 inch f/5 Genesis.
However, sometimes they are just not doable, reguardless of quality of the optics. Bill

#7 azure1961p

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Posted 28 September 2012 - 06:32 PM

I agree that seeing conditions can really make the E and F difficult. Really bad seeing can net me the A thru D while a little better but not great can get me a fifth and flat out good seeing lets me see both. I had a ten inch F/5 that Parks SWORE had a great mirror and not even one time did either e or f show. First try with my 8" and they were there and with the trap showing beautiful diffraction patterns at 200x . That 10" is still an enigma to me as NOTHING. Looked great thru it. The scope that followed was a revelation by comparison.

Pete

#8 Tamiji Homma

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Posted 29 September 2012 - 07:03 AM

Congrats on Trapezium A-F.

Seeing is really a key. I've been trying to observe them with 60mm refractor for some time. A-E was not so difficult but F isn't easy with small aperture.

I was able to see them this morning for the first time. Seeing was excellent this morning 4am PDT. Unfortunately we have high thin clouds. Waiting for half an hour, view got steady momentarily and I was able to see 6 stars :)

I hope coming few day, warm weather clears early morning fogs (marine layers) to reconfirm the observation with larger scope side-by-side.

Setup was Takahashi FS-60Q + 1.6x extender (f/16, 960mm), prism diagonal and Leica Zoom eyepiece at 8.8mm, yielding about 110x.

Tammy

#9 stratocaster

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Posted 29 September 2012 - 11:55 AM

60mm. Impressive. And congratulations!

#10 Tamiji Homma

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Posted 29 September 2012 - 10:55 PM

60mm. Impressive. And congratulations!


Ha ha, not yet congrats :) I saw them for less than 10 seconds. But the way E is seen, I am hopeful to catch F under better condition with 60mm scope.

It is different kind of fun to challenge well known same target again and again with more challenging setup. I enjoy that very much.

Even Polaris is fun when you look at the double at low power, 15x, 16x. It is quite a challenge and good indicator of eye condition, at least to me :)

Tammy

#11 Erik Bakker

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Posted 30 September 2012 - 07:59 AM

Hi Tammy,

60mm might do it, but with a little more magnification. I consistently saw both E and F in my 70mm f/8 fluorite at 140x.

#12 mikey cee

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Posted 06 October 2012 - 11:39 AM

My 10" R30 Istar I feel has to small of a spot size. The stars' discs are so darn pin point I've been having trouble unless the seeing is pardon the pun..."spot" on! :bigshock: Mike

#13 azure1961p

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Posted 06 October 2012 - 01:01 PM

Spot in airy disc or central obstruction? At anyrate on both counts though the diffraction rings with a smaller central obstruction serve to make stars more discernible and as fad as a smaller airy disc due to larger aperture here to one of the reasons e snd f ought to show better. I'm not clear on your statements.

Pete

#14 Starman81

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Posted 29 November 2012 - 06:12 PM

I was observing last night with my 8" dob during the full moon and put the scope on Trap and as I stared E was clearly visible and F showed itself briefly as well. I was using medium power (109x) and I did not know beforehand where they were situated in respect to A, B, C, D. Instead, I saw these 'unexpected' points of light and quickly took out my phone and verified on SkySafariPro what I saw. I was thrilled! A little while later I decided to put in an ortho to see if they would be easier to see, but they were not; instead they were gone! That's when I knew they were heavily dependent on seeing.

#15 Jacques

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Posted 01 December 2012 - 05:08 PM

Even in very good seeing applying the right magnification(s) is key, especially with smaller instruments. Too low power won't show 'em, too high power and they're gone. Some years ago I saw both E and F with a 4"F10 achromat in very, very good seeing but only at 80 and 100x (12.5mm and 10mm eyepieces). F actually "felt" a good deal closer to C than its actual distance would indicate.

#16 C_Moon

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Posted 03 December 2012 - 11:50 PM

Even in very good seeing applying the right magnification(s) is key, especially with smaller instruments. Too low power won't show 'em, too high power and they're gone. Some years ago I saw both E and F with a 4"F10 achromat in very, very good seeing but only at 80 and 100x (12.5mm and 10mm eyepieces). F actually "felt" a good deal closer to C than its actual distance would indicate.


This has been my recent experience. I find that 135x seems to be perfect. I'm thinking that times in the past where I had trouble seeing E & F I was at too high of a magnification.

#17 blb

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Posted 04 December 2012 - 10:33 AM

Viewing the E and F stars is harder than you would think, simply because they are located in a nebula. The nebula reduces the contrast and makes seeing faint stars near brighter stars harder to see. Do not forget that the glare from those brighter stars tends to over power the view of E and F too. E and F are about 3 to 5 magnitudes fainter than the closest brighter star and located only about 3.5 to 4.0 arc seconds away from them. Still they can both be seen with a small scope on a good night from a dark sky site. So scope size is not a factor but seeing (atmospheric steadiness) is a factor and will determin whether or not you will see these stars. So don't give up, keep trying and one night you will see them too.

#18 nirvanix

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Posted 09 December 2012 - 09:46 PM

To never see e and f in a 10 inch dob is very surprising. Either that mirror was really bad or it was something else like improper mounting of primary/secondary, thermal problems, collimation problems...

#19 Tom S.

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Posted 05 January 2013 - 04:34 AM

After reading the preceding comments, I don't feel so bad about never yet spotting F with certainty with my SV102ED 4" 'frac.

Tonight I was outside and thought I MAYBE saw F, but it could have been my imagination.

But I saw several beautiful doubles tonight, especially Theta Aurigae and the perpetually cool CASTOR.

What FUN!

#20 Messyone

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Posted 01 March 2013 - 07:31 PM

I found the f star last night for the first time with my 6" f8 achro and a Pentax XW 7mm. Jumping for joy as I also got the 'pup' for the first time with a 5mm XW :yay: :yay:
Matt
Had to use a green filter on the pup

#21 nirvanix

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Posted 01 March 2013 - 08:55 PM

I found the f star last night for the first time with my 6" f8 achro and a Pentax XW 7mm. Jumping for joy as I also got the 'pup' for the first time with a 5mm XW :yay: :yay:
Matt
Had to use a green filter on the pup


:bow:

#22 CelestronDaddy

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Posted 02 March 2013 - 10:48 AM

Hot dang, WTG :waytogo: :thewave: :yay:

#23 Messyone

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Posted 02 March 2013 - 05:25 PM

Just to prove to myself it wasn't a fluke I did it again tonight! This time the pup was easy to see, no surprises there but now I'm wondering why it took so long in the first place :question: Spent the best part of 4 months looking for this one. On to the trap and now hoping to see some of the others in there....not likely but worth a try. I love my scope. :jump:
Matt

#24 WRAK

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Posted 04 March 2013 - 04:04 AM

... A-E was not so difficult but F isn't easy with small aperture...Tammy


If the current WDS data is correct, then the C-F pair has as separation of 4.5" with magnitudes +5.06/11.5mag - this is certainly a double very hard to split with an aperture below 150mm even under perfect conditions means ignoring the fact that there is also a nebula to consider.
Is +11.5mag not already at the telescope magnitude limit of a 60mm scope?
Wilfried

#25 Bonco

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Posted 04 March 2013 - 04:06 PM

I've found the F member is doable in a 100mm. Actually I think I've viewed it in my 75mm but to be sure I'd have to search my unorganized notes.
Bill






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