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DobbyX

First light with C11 SCT on CGEM after upgrade

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I just had my first opportunity to use my new CGEM 1100 after getting it more than 2 weeks ago from FLO. I am impressed enough that now I want to tell everyone about it. There will be annoyed people in the lab tomorrow.

I upgraded from a C6 SCT on a non-GOTO CG-5 which I will still use a really convenient grab 'n go scope, but as I had hoped, the extra aperture really makes huge difference.

I was observing from a non-ideal site with a building blocking up to 40 degrees altitude in the north, east and west directions, with lots of accompanying lights. However, the seeing was good after the clouds went away and it was warm enough to be in a t-shirt for the entire session till 1am. Skies were just about mag 5 NE limit towards the zenith with a hand blocking the offending lights.

So, I was trying out lots of shiny new kit for the first time: the C11, the CGEM mount, a 2" WO dielectric diagonal and a 40mm WO SWAN 70° eyepiece.

Setup took much longer than with the 6", as expected, and I stubbornly tried to perform a 2 star align without using a finder, before conceding defeat in a rapidly losing battle. However, after getting set up, I can see that having GOTO is really, really convenient, despite taking away a fair chunk of the fun. However the 11" is a bit too big to unclamp and manhandle, and it doesn't let you do that without losing alignment anyway.

Onto the actual observing; I started with the same targets that I tried last week with the 6" for comparison:

M13 - With the 6", this was quite fuzzy blobby, and contrast wasn't great due to the gibbous moon. Some of the edge stars resolved but the core was a single mass. With the 11", wow, looked stunning with the 40mm, with lots of the brighter core stars being resolved, the longer time spent at the eyepiece the more could be picked out. Even more so with a 15mm SWAN, although I noticed the collimation may need touching.

M57 - GOTO put this dead centre slewing from M13, not that it is difficult to find, but I was impressed by the pretty quick slew speed. With the 6" and 25mm, I could just about make out a bright blob. Going up to 15mm with a UHC filter gave enough contrast and size to make out the ring. 11": Bright and easy. Ring structure was visible at 40mm and 15mm #nofilter. Some greenish colour was perceived too #nofilter.

M27 - Once hard to find, but has got much easier since I got a Telrad on the 6". The structure was not really apparent, just about visible at 25mm with filter. 11": I had the 15mm with filter in and the GOTO placed it dead centre again after a meridian flip, but still took about half the time it would have taken to find it myself. Nice. Shape and structure easily visible. Pleasant star field too with the 40mm.

M31 - In the direction of bright lights, but the core was easily visible in both. Sky was too bright to see much of the outer regions though.

M33 - Couldn't see this in either. Was very close to building.

Another meridian flip.

M51 - Couldn't find this in the 6", even matching the field stars I was not able to see it. Sky was too bright. With the 11", I was able to easily see the two cores together.

Albireo - Colours looked richer in the 11"

Double Double - Much easier to split with the 11".

Then I ran out of things that I had tried for in the 6", so I continued with some other objects, including more obscure ones the hand controller said was there, but then pointed at some trees or buildings after performing a meridian flip. Hooray for not looking up where your objects are and relying on GOTO. I know there is a horizon limiter but didn't bother to use it.

Wild Duck Cluster: Went behind some trees contiguous with the building.

M101 - Just about managed the core. Was very close to the building's lights.

Mini coathanger - Looked like a coathanger, small.

Coathanger - Couldn't fit the entire thing in the 40mm SWAN. Nice and bright though.

Kemble's Cascade - Nice to follow with the 40mm. No way was I going to fit it all in one view.

Then I had another few more looks at M13 and M57 before packing away, due to the need to work tomorrow, which I have completely disregarded by writing this all for the past 2 hours. Oh well. I am very impressed. The 11" is really nice. GOTO, I'll admit, is quite nice when it starts working, and so are wide AFOV eyepieces. I haven't tried a comparison between the stock 1.25" mirror diagonal and the 2" WO dielectric one, but I probably won't bother.

I would like to be able to find things myself in the future, which you can apparently do with a park feature on the CGEM, but I will wait until next time after I have installed a Telrad mount.

I will be moving down the road in a few months to a house with an accessible roof terrace thing which is shielded from the street and has a good view towards the south, west and north. Unfortunately I will be on the ground floor, but carrying it all up and down 2 floors isn't insurmountable. Hopefully, the views and object choices get much better then. Otherwise, I will be stuck begging for lifts to better skies.

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Nice report and glad that you are ejoying your new telwscope!

M33 is really tricky because of the low surface brightness. You need a dark sky for that one.

Thanks for sharing!

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