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John

Orion Nebula and the Trapezium - 27/10/08

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I've just managed to grab 45 mins of observing with my 8" Skywatcher dobsonian. Orions belt and sword had risen over my neighbours roof so M42 was the obvious target. Started with 22 Nagler - lovely - loads of nebulousity and I'd swear (wrongly I'm sure !) that there were tints of lime green in it. Then on to the 16mm Nagler - wow ! - M42 is really centre stage now with it's swirls and arcs of nebulousity filling the field of view.

As the scope cooled I moved up to the 7mm Nagler (171x) and really "got in amongst" the great nebula - the dark "fishes mouth" and the swirls of matter adjacent to that area were really emphasised and the 4 principle Trapezium stars split wide apart.

I then made a brief diversion towards Orions belt to have a look at the multiple star sigma orionis and 4 componants were nicely reolved.

Back to the Trapezium now and a careful scrutiny with the scope nicely cooled by now revealed the elusive (to me anyway) E and F stars - 1st time I've been able to clearly see both of these with the 8" scope :)

Thin cloud has now rolled across so I've had to retire to write this up with a glass of chilled Californian Chardonnay as company - a nice little session and why I love portable scopes :)

John

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Congrats on seeing the E & F stars :)

I too managed an hour or so and concentrated on M42 as it rose above the rooftops. Clouds kept rolling over it making me wait 5 mins or so between glimpses and there were a few spots of rain about as they passed over so I grabbed a few looks at M38, M36 and M37 in Auriga as the cloud passed over Orion.

I tried first with the Pentax 30XW and the neb was very bright and green. Then I popped in the Ethos 13 to get closer. I couldn't resist popping in the UHC filter and I was pleasantly surprised at the extra contrast (much better than last time I looked months ago when it was lower down in the SW).

The wings stretched beyond the field of view (45' with the Paracorr attached) and I had to move around to take in the extra visible length of the wings. The dark fish mouth cutting into the middle of the wings near the trapezium stood out strongly against the nebula. I could also easily see M43 off to the other side of the fish mouth surrounding Nu Orionis.

I removed the filter to see if I could see any colours other than green but wasn't successful. The sky background LP here spoils the view somewhat so other colours might be visible at a dark site.

I tried and failed to see the Flame neb(?) NGC 2024 near Alnitak. Possibly light pollution washing it out or me aiming too far from Alnitak. It should have been in the FOV with Alnitak off to one edge but I couldn't detect it. I'll have to have another go at that.

I was just about to attach the Powermate to get closer to the trapezium to have a go at the E & F stars and an ominous looking cloud bank was sweeping in from the northwest. It looked laden with rain and sure enough no sooner had I got the eyepieces packed away and it started raining. Luckily, the 'scope was in a horizontal position but by the time I got it inside it was dripping wet (It's dried off now though and ready for another outing hopefully tomorrow or later this week).

A short session but worth it :D

Just looked outside and it's cleared up again - wonder how long the rain lasted. I'm betting it stopped as soon as I got everything packed away :)

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Sounds like you had a good session as well AN :)

What a fantastic area of the sky the Orions belt and sword is :)

John

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Sounds like you both had great views of Orion.

I'm going to wait a little longer as I'm not really an early bird.

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I too had the 16" trained on the Orion nebula at the very end of last night's session. I am surely definitely positive that, like you two, I saw a greenish tinge to the nebulosity. When I added the UHC filter, contrast was improved and the colour exaggerated.

But I think there's something wrong with my telescope and I've yet to work out what it was. I could clearly make out A-D of the Trapezium but E and F totally eluded me - the stars were blobs, not points. I'll start a new thread about this...

I could make out M43 and also the Running man too. The core detail in M42 was splendid, but I was quite disappointed how little the nebula extended out from the core. I expected more from the huge mirror. Conditions were fine though.

Andrew

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I was out in my backyard (in a city) at around 4am last week but with lots of light pollution; orion still looks amazing

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The E & F stars are challenging for a number of reasons:

- they are pretty faint - mag 10-11 depending which reference you use.

- they are closest to the brightest of the other Trapezium stars, A & C.

- they tend to get drowned out in the surrounding nebulosity.

In my 8" scope last night (early this morning actually) they appeared as tiny pinpricks of light that came and went a bit as the seeing varied but were definately there. I took the precaution of searching for them BEFORE I checked a diagram to see where they were supposed to be :)

Your 16 inch should pick them out without too much difficulty on a decent night Andrew although I guess your collimation would need to be pretty good to get as tight star images as possible. How is your scope doing generally on tightish, uneven magnitude doubles which what the Trapezium A-E and C-F pairs are ?.

John

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Someone sent this to me about 5 years ago. I've no idea if they drew it or stole borrowed :) it from a site somewhere, but it's the best diagram of the Trapezium I've ever had.

post-13732-133877348936_thumb.gif

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Your 16 inch should pick them out without too much difficulty on a decent night Andrew although I guess your collimation would need to be pretty good to get as tight star images as possible. How is your scope doing generally on tightish, uneven magnitude doubles which what the Trapezium A-E and C-F pairs are ?.

Hi John, I've started a new topic on this to avoid hijacking yours.

Carol - great diagram. At least I now know where I can imagine the E and F components :)

Andrew

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I managed to spot the E & F stars tonight :)

I'd waited around 2 hours for Orion to clear the rooftops so the mirror was as stable as it was going to get. I was at x230 with the Ethos, 2x Powermate and Paracorr but I could have benefited from more magnification as it was still quite small in the FOV. I found the E star first and at mag 11 against the light from the nebula it was tricky to see at first. After a minute or so I saw a faint star forming a flat triangle with A & B. Once I'd seen it, it was relatively easy to spot after moving off target and coming back.

I couldn't see the F star at all at first but perseverence paid off. It's the same magnitude as E but the brighter C star in close proximity made it trickier to see. I went back to it later when Orion was closer to the meridian and they were easier to spot although F was still tricky and closer to C than E was to A

I've checked what I saw with Carol's piccie above and I'm sure the F star was closer to C than the diagram indicates. My observation put the F star distance from C about two-thirds the distance from A to E but it was still at that angle from C. It was a bit less than half the distance shown in the diagram from C.

Could this be because of proper motion over the years since that diagram was done?

Now that I've got that diagram memorised, I'll have another look next time I'm out.

I'm not even going to attempt G & H at 16 mag - I've got no chance of spotting them :)

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Well done AN :)

I picked them up again last night in the 8" dob. I tried for them with my 4" refractor as well but I don't think I even got close. The dob was far outperforming the frac over the past couple of nights which have been very clear in the early hours.

The 13mm Nagler T6 with the dob put up a fabluous view of M42 - I can imagine that the Ethos 13mm and your 12" must be really something special :)

John

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Well done AN :)

I picked them up again last night in the 8" dob. I tried for them with my 4" refractor as well but I don't think I even got close. The dob was far outperforming the frac over the past couple of nights which have been very clear in the early hours.

The 13mm Nagler T6 with the dob put up a fabluous view of M42 - I can imagine that the Ethos 13mm and your 12" must be really something special :)

John

Well done to you to :D I found E & F a little tricky at first and I imagine I would have had even more trouble trying to spot them in an 8".

My collimation was as close to perfect as possible last night so yours must be too. I checked collimation after the 'scope had been out for a couple of hours using the catseye autocollimator and a bright light and it was still spot on.

I tried looking for the running man nebula to the north of M42 last night using the UHC. It wasn't until afterwards a check in Starry Night Pro revealed this neb as a reflection neb - doh!, hardly surprising I couldn't see it, one for dark sites I think.

The flame neb near Alnitak still eluded me too.

btw the Ethos + Powermate + Paracorr gives me a mag of x265, not x230 as I wrote above. It's x230 without the Paracorr.

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