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James4

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Everything posted by James4

  1. The Crab Nebula is quite small, so when you are scanning for it at low power it is easy to miss. Once you've seen it through the scope you will always be able to find it again. I remember never being able to find The Ring Nebula - I had a 4" Refractor and was expecting something much bigger - I was passing it by for probably a year.
  2. Hey Jonathan, I've been troubled with the eyepieces fogging up too. I was thinking what about all this 'anti-fogging' - 'nitrogen-purged' - 'blah de blah' they always write on the ads for eyepieces. But the solution is - stick them in your pockets. Put all your keys, change etc out of the way and put your best three E.P.s in your pocket - no more fogging!
  3. yes you can see the Supernova light explosion coming from the right in the last scope image. Bring back the WW2 lighting wardens!
  4. Jupiter Second time out with the C9.25 and Jupiter served up a surprise. At first look I thought - Oh yes, I'm not falling for that one again - one of those apparent moons must be a star. But no, it was actually the four Gallilean moons in an unusual (what do I know, its cloudy here for 4 months of the year) configuration. Crayford Focuser I had trouble with vibration when focusing at at 470x (5 mm ep). I need to put a crayford focuser on the back with fine focus control. F/6.3 Reducer I recently had a C8 and found when using the F/6.3 Reducer I could bring only one of my eyepieces to focus - a skywatcher 42mm. I wanted to try this again with the C9.25 and with my Celestron 32mm, 13mm and 5mm 2" eyepieces. Brilliantly they all came to focus. Than means I can fit the Pleiades and the full extend of The Orion Nebula into my field of view. I already sent away for a 56mm Erfle to get a wide field. If that focuses with the reducer in place I will be down to 42x and approx 1.2 degree FOV - not bad for a scope with a 2.3 metre focal length. Again I tried the UHC filter - this time at low power with my 32mm Ultima LX in place. But it was Negatory on the HorseHead (a real ask that one - but its on my to do list for 2012), the California Nebula and The Rosette. Now I know the Rosette is not that hard (although I have never seen it), I just need a dark sky and no lights shining on me. Finally I looked overhead and found a striking view of both M37 - (this normally looks like I'm viewing a cluster of small fine stars from some distance, but this time 180x [13mm ep] put me right up against the cluster which appeared to have slightly blue stars with a redish one in the middle) - and The double cluster. The Double Cluster was superb - the stars were bright points - no sign of collimation issues overhead - perhaps the poor seeing is responsible for my less than impressive Jupiter views after all. Looking forward to next time out.
  5. First light for my Celestron C9.25 was pretty chilly at -2 degrees C. It was Thursday night and I had asked for Friday off work in the hopes that the Clear Sky Clock would come through with its promise of clear sky at 9.00pm onwards. Minutes after making this request, the clear blue skies seen from my work desk clouded into a heavy grey shroud. Not kidding - I managed to change the weather pattern from clear to cloudy just by asking for time off for Astronomy! I was not feeling confident that night but I took a look outside at 8.45pm and I saw Orion rising in the East in a fast clearing sky! CSC your are superb! I threw the scope up in case the clouds returned. I did a quick align (which is no alignment at all) and slewed to Jupiter. I used a 13mm Ultima LX 2" eyepiece for 180x on Jupiter. My first look did not overimpress me - I was expecting great things from the legendary 9.25. But honestly I've struggled to get a satisfying view of the Gas Giant since September. In recent views with a 6" refractor Jupiter has looked colourless and grey. I wondered if The SCT collimation may be a little off. Thierry Legault has an excellent SCT collimation guide on line. I tried this and found right away that I needed to dial it in a little. I used Rigel defocussed at 180x to even out the light doughnut. When I went back to Jupiter, even although it was sinking in the West, it had improved - I noticed the moons were more definately spheres - still with some sparkles but not bad. I went to 470x (5mm eyepiece) on Rigel and could see the diffraction rings when defocussed but I could also see a river of air blurring past Rigel in an East/West direction. I've never seen such a clear view of unsteady seeing. The image of Rigel was distorting like a flag in the winde - it was much too unsteady to see the airy disk in focus for fine collimation. I decided to just enjoy the views as is. At 180x (13mm ep) on Jupiter, I noticed fairly annoying mirror shift. Jupiter moved more than its own diameter across the FOV (field of view). I was alarmed by this - this would be no fun at high power. My previous C8 had almost no mirror shift at all. I decided to rack the focuser all the way out and back in again. This seemed to greatly reduce the problem. A much smaller shift now, I've since ran the focuser fully in and out several times. I decided to think about putting a 2 speed crayfor focuser on the back of the SCT. Next I wanted to try my Celestron UHC filter. I slewed to Orion and studied The Orion Nebula at 73x for a few minutes. It was not obvious at first but after a few minutes I realised the Orion Nebula cloud was definately bigger than I had seen it before. There was no colour but I was seeing most of the sweeping arms and cloud area inside that. The extra aperture was pulling in some more light. I then installed the 2" UHC Filter. There was not an obvious difference -- perhaps a little bit more to the cloud, but I was standing in full glare of the street lights. I hope under dark skies I will notice the improvement I saw some months ago with borrowed filters. They were of higher price (and maybe quality) - a Lumicon versus my Celestron. If I can, I will compare them head to head. The Trapezium was an open uneven square at 180x (13mm ep) but I could see the stars were fluctuating in the uneven seeing. After seeing the river of air rushing past the image of Rigel, I realised the scope was probably performing pretty good for the seeing conditions. There was a cool breeze and around 10.30 I ended first light.
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