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NGC 891....first light with the fully functioning 12 inch RC.


RobH

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Finally, after much trial and tribulation, I have my camera/scope combination right and working correctly....no camera issues (my old H18), or problems with astigmatism with the scope.

This is a target I’ve imaged before, but I like this galaxy and it’s well positioned at the moment, so chose it as my ‘first light proper’ for the rig.

A quick bit of background info.....

NGC 891 in Andromeda is one of the most photogenic edge-on spirals around and about 30 million light years away.
We are looking at light that left near the start of the Oligocene epoch, the time of the transition between the tropical Eocene and the more modern ecosystems of the following Miocene.
This is the time when grasslands, and the associated grazing animals were spreading, and the tropical forests were becoming limited to the equatorial belts.
The planet was getting cooler and more seasonal, and in Europe, the Alps were rising as the African landmass continued to push northwards.
There was also a major extinction event, where Asian fauna replaced the previous European fauna.
Some species of terrestrial mammals returned to the oceans about this time. Amongst these were the ancestors of the dolphins.

The imaging data is......

Telescope. 12 inch custom Ritchey Chretien with GSO optics (started life as a standard GSO, but very little of the original scope remains)

Camera. Atik 460 EX mono.

Filters. Baader LRGB & Hutech IDAS filter.

40 x 8 minutes Luminance

22 x 220s Red, 20 x 200s Green, and 22 x 240s Blue.

All subs binned 2x2, and an AP 0.67X focal reducer used, giving a focal ratio of F5.4

Total imaging time. 9 hrs 15 minutes.

As I binned the data 2x2 (giving a resolution of 1.14 arc secs per pixel), for the processing, in order to avoid artifacts, I substantially increased the image size, and then reduced it again for the final image.

Imaged on the 29th & 30th November 2013 from Weymouth, Dorset.

gallery_1757_60_421276.jpg

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Heh heh heh, he's damned good isn't he???  :grin:  :headbang: 

What a drought this has been, Rob! We haven't seen you for ages but, by all that's holy, this is a crisp piece of work. You've really worked at the RC and got there in the end. Stars are great and the dust lane is prickling with detail.

Rather a decent way to reappear, I'd say!

CHeers,

Olly

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Rob, with all the work you've done on the RC did you ever consider changing the spider vanes to curved vanes and get rid of the diffraction spikes. I have an 8-inch version and its omething I'm considering. Either that or a small mask on the front of the vanes to break-up the straight outline?

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Hi Francis.....no, I like the spikes ! I put off getting either a newt or an RC for ages due to diff spikes, but once I'd got one I found that I rather like them and think they add a bit of sparkle !!!

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Thanks all....it was a real relief to get this out and online.....I was getting to a point where the technical troubles of the past 3 years or so had almost made me give up and take up knitting....thanks again for the kind words.

BTW....I forgot to add that with this scope at F5.4 and the camera binned 2x2, the image scale is 1.14 arcsecs per pixel, which is about the best I can realistically expect from my location I reckon, although I do plan to image at F8 in the spring for some of the smaller PN's and Arp objects.

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