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MimasDeathStar

Splitting the Trapezium with a 130mm scope

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Hello everyone

I'm on the cusp of upgrading from my trusted 70mm refractor to a second hand 130mm Heritage 130p scope. I've read lots about the Trapezium and am really keen to have a look at it in the coming weeks. I was wondering whether my 130mm will be a good scope with which to try it - and what I should be expecting? I guess I'll be able to get ABCD? But what about E or even F?

Does anyone have any recommendation for powers? I've got a 25mm and a 15mm plossl and a 2x Barlow.

Many thanks all, clear skies!

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Hi @MimasDeathStar,

With a theoretical maximum magnification of 260x your Heritage should be more than capable of revealing E & F stars.

You will need a night of good steady and transparent seeing, but any good eyepiece giving about 175x upwards should show them.

Down here in Oz I see them both every time I look for them with my f4.9 12 inch Dob and any eyepiece from 8mm to 4mm.

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I'm sure that seeing will be the biggest issue for you. Geoff has the advantage of Orion being much higher in the sky than it ever gets for us, so that makes a huge difference. I've never seen E and F with my 130p, that's not to say it's not doable, but you will need a night of excellent seeing and M42 at its highest.

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Same here regarding seeing, you may try three nights in a row without success then, suddenly, one night you'll see them. E&F stars are such tiny delicate little pinpoints, they are easily overwhelmed by a boiling atmosphere.

Is it ever fun to delve into the trapezium, i saw E&F stars with my 150 mak recently, it was a rewarding adventure.

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Finding the right magnification is the key to getting E & F Trapezium. Not too little and not too much. Often I find that 150x - 200x is about right. I can see them regularly with my 120mm and 130mm refractors and sometimes with my 100mm / 102mm ones but not all the time with those.

 

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With my 127 Mak (119mm clear aperture), a good night will show the F star, and an excellent night the E star as well. As John indicates, the right magnification is quite important to see both E and F, as well as excellent seeing + patience.

Chris

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If its any consolation, i'm yet to see the elusive E & F myself yet.

On those rare nights when i can actually get the scope out the seeing has never co-operated.

 

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I've got an 8" Dob and on a good night can get to x240 - I've never seen E and F either.

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As above, you need certain parameters to come together.  Here is a previous thread I started which contains a few tips.

 

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2 hours ago, JOC said:

I've got an 8" Dob and on a good night can get to x240 - I've never seen E and F either.

Hi JOC,

I also have an 8" dob and used a 5mm BST to achieve x240 - I have managed to locate the F star with this set up. As mentioned above it literally is the smallest spec. No joy with E yet but I am hoping with the right conditions it will be possible.

In another thread we have been speaking about eye pieces for splitting stars and I am considering the SW 4mm planetary eye piece to achieve x300 in my 8" - However this might not necessarily be suitable to spot the E  star as it could be a big to much power.

Baz

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1 minute ago, Barry-W-Fenner said:

Hi JOC,

I also have an 8" dob and used a 5mm BST to achieve x240 - I have managed to locate the F star with this set up. As mentioned above it literally is the smallest spec. No joy with E yet but I am hoping with the right conditions it will be possible.

In another thread we have been speaking about eye pieces for splitting stars and I am considering the SW 4mm planetary eye piece to achieve x300 in my 8" - However this might not necessarily be suitable to spot the E  star as it could be a big to much power.

Baz

To be fair now I have read through the comments John has pointed out roughly the right power required for these particular splits.

Baz

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52 minutes ago, Barry-W-Fenner said:

Hi JOC,

I also have an 8" dob and used a 5mm BST to achieve x240 - I have managed to locate the F star with this set up. As mentioned above it literally is the smallest spec. No joy with E yet but I am hoping with the right conditions it will be possible.

In another thread we have been speaking about eye pieces for splitting stars and I am considering the SW 4mm planetary eye piece to achieve x300 in my 8" - However this might not necessarily be suitable to spot the E  star as it could be a big to much power.

Baz

I have the SW 4 mm planetary and a SW 250 px... For the last 10 months (ever since I had that scope), I've never had a night that was clear enough to get a good resultwith these together.

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I've only ever seen the 6 stars once in a 150p it was one of the best nights I had ever seen, clear, crisp and seeing was brilliant. 

I've now got a 127mm refractor and I am waiting for a clear night to have a go but this weather is making it very awkward. 

Hopefully we get some clear nights soon otherwise I won't get a chance as I cannot see anything south. 

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I'm getting E & F Trapezium intermittently with my Tak 100 refractor this evening. The Pentax XW 7mm (129x) is showing them more clearly than my shorter focal length eyepieces. E shows more often than F but now and then both pop into view together. Must be those little moments of steadier seeing :smiley:

 

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Very jealous of you all who’ve seen E & F. I’ve had a few determined goes but no joy. Even when Orion is high, my view is directly over a nearby row of flats, so I’m never going to get undisturbed air in that direction, I think. :(

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Just now, Captain Magenta said:

Very jealous of you all who’ve seen E & F. I’ve had a few determined goes but no joy. Even when Orion is high, my view is directly over a nearby row of flats, so I’m never going to get undisturbed air in that direction, I think. :(

Seeing is everything Magnus. The best I've ever seen them was with one of Gavin's refractors, probably the 160mm but might have been the 130. They were just there, bold as brass, no effort required to see them. Was quite amazing. The right combination of a superb scope and fab seeing.

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12 minutes ago, John said:

Must be those little moments of steadier seeing :smiley:

Indeed @Johnand @Stu

With Orion being high in the sky here it's not really much of a challenge to see them. I'm very impressed you can see them at only 129x John, shows how good your equipment is !

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Just been out for an hours viewing. No moon and good seeing and I managed both E & F at x150 mag.  E was fairly easy to spot tonight with F popping in and out of view. I am chuffed to bits at spotting them!

The rigel split was very easy to get tonight at x150!

Managed some great targets in the hour I was out, a real quality bit of time at the eye piece!

Baz 😁

 

Edited by Barry-W-Fenner
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4 minutes ago, Barry-W-Fenner said:

Just been out for an hours viewing. No moon and good seeing and I managed both E & F at x150 mag.  E was fairly easy to spot tonight with F popping in and out of view. I am chuffed to bits at sporting them!

The rigel split was very easy to get tonight at x150!

Managed some great targets in the hour I was out, a real quality bit of time at the eye piece!

Baz 😁

 

👍👍👍

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Great stuff Baz !!!!

I've been in and out several times tonight due to clouds blowing over and light rain. Bit frustrating but I did do some observing at least.

Now you have seen E & F they will be that much easier the next time around, as long as the seeing is decent.

 

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Just now, John said:

Great stuff Baz !!!!

I've been in and out several times tonight due to clouds blowing over and light rain. Bit frustrating but I did do some observing at least.

Now you have seen E & F they will be that much easier the next time around, as long as the seeing is decent.

 

This is very true, I noticed that E was definitely easier to spot this time than when I 1st tried to spot it. Most likely the seeing and no moon were the main reasons but I was familiar of where to look for it so it wasn't to bad. F on the other hand you do have to work for! Great to find it though.

so glad we have all managed to get out and enjoy the sky even if it was short, it's long overdue.

Getting windy again here now.

baz

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I too got an hour outside tonight from 8.20 ish til c9.30pm. Using my Tak FS128 with Revelation Binoviewers (with which I am very pleased), and in very good seeing (although quite windy), I got a lovely view of the A-D stars - but no E or F Stars seen..very comfortable viewing at c x100 to x170 though.

A little later, switching to cyclops mode, both E and F were very obvious at c 150x with a Carton 10.5mm UWA fitted with a x1.6mm Barlow nosepiece. I also saw both E&F using the Carton Zoom at 7mm (giving c148x).

So my take on tonight is that binoviewers lose around half a magnitude or more versus cyclops viewing, and this tonight made the difference in spotting these two tiny, faint dots..

Perseverance is vital!😁👍

Good luck with your 130p!

Dave

Edited by F15Rules
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Looks very nice out there now, Clear Outside was right! No observing for me though, was quite blustery and had a few other jobs to do this evening.

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Blowing a gale here clouds flashing accross the sky in between I have seen Leo high up in a very favorable position, unfortunately Orion is now SW so I have no chance of seeing it in my scope. 😢

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