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Oh, so THAT'S a star! 16th December Report


Andrew*

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Yesterday's was the first entry in my observing journal since 16th November. The weather has been that pants.

Conditions weren't good. The sky was quite milky, and limiting magnitude was very low.

Started off with the 16" trained on Betelgeuse to check collimation. So far off it was unreal. Plus the out of focus image showed a crescent of brightness. Looked at the primary :shock: Absolutely covered in condensation. It appears the storage place for the dob had leaked and got very wet from all the recent rain :x So I propped up a 12v hairdryer in the tube to get to work on the moisture while I uncovered the equatorial set-up and had a look through the 8" instead.

Auriga was looking nice, high up, so I found a couple of her clusters. M36 showed nice contrast against M37 - the former being looser and of brighter stars, while M37 glitters with a multitude of fainter members. M38 decided to elude me.

So I found M42 and took a nice long look at that. I had a lovely new eyepiece to try out. The legendary 20mm Type 2 Nagler - a large and heavy hand grenade, but often regarded as one of Nagler's best. At f/5 this performed beautifully and showed precise tiny points, with some of the inevitable coma showing up right at the edge of the FOV.

By now the 16" had dried up and I slewed to the same target. M42 took on a new dimention with the extra aperture, and the Nagler still performed admirably. NGC 1977, the Running Man, showed up very clearly with a dark line through it - one of his legs, I think. Unfortunately high power didn't seem to want to show me tight stars. Really don't know what this is now because it's not collimation... This meant the E and F components in the Trapezium failed to reveal themselves. However, the brightest member appeared slightly asymmetrical... ???

Steadily a bank of cloud had been wandering it's way over to the South, so I considered up some easy targets in the vicinity.

If the belt of Orion made the base of an L shape, M78 makes the tip. When it appeared in the eyepiece, I spotted not one patch of nebulosity but two in the field. The other has turned out to be NGC 2071. M78 appeared as an oval patch of nebulosity with two eyes glowing from the centre. I have since learned that M78 is the brightest reflection nebula (the type seen in the Pleiades) in the sky, and the two "eyes" are responsible for lighting it up so we can see it. I found this a fascinating object often overlooked due to its proximity to far more popular targets.

I was getting bullied still further South now so I tried for a totally new object, which involved a foray into a totally new constellation. This was NGC 1788, another reflection nebula, found by going from Rigel (beta orionis) to Cursa (beta eridani), half a step further, and a little North. I found something but couldn't make a definitive identification due to increasing cloud cover.

And by now the entire sky was covered and it was already time to go in.

Was short, and a little frustrating, but a godsend given the length of time I've been waiting to get out!

Thanks for reading - goodnight!

Andrew

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Lovely report Andrew...

I had a dewed up primary last time I looked and it really effects your seeing. It is very similar to a collimation error and I bet quite a few people have been fooled by this.

Have yet to point my 16" at Orion for a long period yet so your report about seeing the leg in the running man is very promising. Btw are you using any filters such as UHC or O111?

Also have put NGC 1788 on my to do list if I ever have another clear night....

Thanks

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Thanks :(

Have yet to point my 16" at Orion for a long period yet so your report about seeing the leg in the running man is very promising. Btw are you using any filters such as UHC or O111?

No filters, Doc. No particular reason why I didn't try a UHC TBH - just laziness I guess.

I need to try for 1788 again.

Andrew

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Really nice report Andrew, enjoyed the read.

I feel your pain with the dew and collimation. My Meade suffers the same. Took it out this morning and the collimation was way off. I need to get the chesire back out and check things. My image just slightly pulls, yet the laser says it's spot on.

And also find a way of stopping the moisture building up on the primary in storage. Pretty sure that's due to my dustcap which isn't sealed.

Adding M78 and NGC1788 to my 'need to see' list.

Oh and the 20mm T2 sounds the business.

Russ

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Nice report as usual Andrew

....I feel your pain with the dew and collimation. My Meade suffers the same. Took it out this morning and the collimation was way off. I need to get the chesire back out and check things. My image just slightly pulls, yet the laser says it's spot on.....

Could the collimation issues be caused by weak support springs on the mirror cell ? - I'm sure I've read of that issue with some Lightbridges ?.

John

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Thanks for your comments.

Oh and the 20mm T2 sounds the business.

Oh, it is. Very weighty but so immersive.

....I feel your pain with the dew and collimation. My Meade suffers the same. Took it out this morning and the collimation was way off. I need to get the chesire back out and check things. My image just slightly pulls, yet the laser says it's spot on.....

Could the collimation issues be caused by weak support springs on the mirror cell ? - I'm sure I've read of that issue with some Lightbridges ?.

You could be right, John. I was thinking of ordering some Bob's Knobs for the 8", so might as well get some springs at the same time.

Andrew

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