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Can't upload files to Flickr right now (something wrong on their side) so I'm sharing this directly here - we had clear skies and good seeing saturday evening, which allowed me to collect a lot of excellent data.

This is the first result, a 6 frame mosaic of the area between Aristoteles/Eudoxus on the left and Hercules/Atlas on the right, with the "Lake of the Dead" (Lacus Mortis) in between.

This is the first time I really get the feeling I'm getting close to the optical limits of my 20" telescope - better seeing can still tighten things up a bit (and probably increase the contrast by a lot) and this was done using an IR-pass filter, meaning that switching to a Red or Green filter (if the seeing would permit it) could still increase the resolution quite a bit - but barring truly exceptional seeing this is about the best I can expect to achieve.

Image scale is 0.1"/pixel, which corresponds to about 200 meters on the moon.
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Since I bought my 20" telescope I've been systematically trying to improve my results - I live in a zone on the edge between red & orange (SQM typically is between 19.6 and 20.0 depending on humidity and time of the night) so going really really deep remains a challenge, even with such a huge telescope.

But this subject was definitely on my bucket list - imaging a gravitational lens - the Cosmic Horseshoe in Leo is a prime candidate, at 10" in diameter it's actually quite large, though at magnitude 20.3 getting enough data to be able to really see the lensing isn't simple. I used an LPR filter in front of my ASI294MC Pro to reduce the light pollution to somewhat tolerable levels and took (for my standards) lang exposures at 300s per frame, 48 frames got me to 4 hours of exposure, close to the max I can practically do in one night with this object high in the sky.

And... it really worked - not only did I visibly capture the "arc" of the lens, but I could reproduce the colours as seen in the Hubble reference shot, with the lens galaxy yellowish and the lensed galaxy blue - they're at astounding distances (5 billion ly and 10 billion ly respectively) - the lensed galaxy is definitely the most distant object I've ever consciously imaged.

You can see the full image on Flickr: https://flic.kr/p/25tgctK

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I haven't been doing a lot with my new-ish 20" F/4 equatorially mounted Newtonian in the past few months, mostly thanks to the horrible weather we've been having (December 2017 & January 2018 have been the cloudiest months in recorded weather history in Belgium and november wasn't too brilliant either) but tonight, between cloudy spells I managed to get some pictures I'd been meaning to get now that Ceres is in opposition and an enormous 0.79" in diameter.

The attached image is a combination of two shots, one of Castor, the lovely double star in Gemini and one of Ceres (with a faint background star nearby) - I processed them in the same way (Lucy Richardson deconvolution, same settings) so the results would be somewhat comparable - I was going to look for a star closer in brightness to Ceres, but the clouds decided otherwise. Still, Ceres's visible disc was obvious even when recording - it looked very similar to the way you can see Jupiter's moons while recording with a smaller scope - the difference with a star is quite obvious.
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Yesterday night the seeing was very very good by Belgian standards, permitting me to take a series of really high resolution shots with the 20" telescope, blowing past anything I've ever done using the old 12" scope - be sure to enlarge the "Lunar North Pole" mosaic, at 13200x2800 pixels it's still quite sharp at maximum magnification!

https://www.flickr.com/photos/bartcentral/shares/d0y824
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A giant lunar mosaic, taken at 0.15"/pixel but downscaled to 'only' 0.3"/pixel because the seeing was too variable to justify the full res.

A 38 frame mosaic taken with an ASI1600 camera and a 20" Newton telescope.

You can see some more detailed imagery (taken with an ASI174 on the same scope) at https://www.flickr.com/photos/bartcentral/shares/U04K10 - those are mosaics too, but of only small sections of the moon, I've marked and labelled the major landmarks on each shot.
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I've added some colour to my september image of Stephan's Quintet - the conditions during the taking of the RGB data were atrocious, with wind gusting up to 40kph and terrible, terrible seeing (the september L images have the stars at roughly 2 arc seconds, the RGB they were double that, and my autoguider precision was 3-4x worse than it normally is (mostly due to the gusts buffeting the telescope, a 20" scope catches a lot of wind)

But still, this combination image uses the higher resolution from the old L image and the recent colour data with very nice results IMHO
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After a few months spent adapting the telescope (and a lot of other, non-telescopey stuff) I'm finally back up and running in the new observatory.

This is 3 hours of total exposure (though part of it with the secondary mirror fogged up, so far less data than it should have been) on Stephan's Quintet, an interesting little group of galaxies in Pegasus.

Taken using the 20" F/4 Newtonian telescope and a Zwo ASI1600MM-Cool camera
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I shot the Great American Eclipse 2017... from a hilltop in South-Western France :)

It was right at the edge of the visibility zone, with a bite appearing in the sun just minutes before sunset, but I managed to find a sufficiently clear western horizon to see it :)

Canon 7dMkII with Tamron 150-600
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Going big - I've completed my new observatory with a lovely, yuuuge 20" F/4 Newtonian telescope inside. On May 5th I had my first decent seeing with the moon nicely positioned in the sky.

All of the attached images were taken that day, using an ASI174MM camera with an IR742 filter and a Televue 5x Powermate (except the big mosaic, that was taken with a different barlow at slightly lesser magnification).

I'm sure this isn't even close to the best the setup will be capable of, but it's still prety darn sharp :)
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07/05/2017
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It's not a new picture, but the observatory which ignited my interest in Astronomy and where I'm an active member is looking to install a big new telescope in the big new dome we're getting for our 50th anniversary and we're trying to use Crowdfunding to get it.

You can read about it (in Dutch) at
http://www.mira.be/50-cm-voor-50-jaar
50 cm voor 50 jaar
50 cm voor 50 jaar
yeee-haaa.com
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