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Just wanted to share this time lapse of the Liverpool Telescope at work.
Note the large number of movements the scope makes during one night. Every time you see it tracking the night sky, is one imaging session. The data captured during such sessions, is representative of what @gorann and I have been working on for the past time.
Also note that the 'obsy' is completely remote controlled. You can see the various instruments being changed in this video.
I started a while ago shooting the bubble and the M52, first in Ha, then RGB and then O3 too. 25min on each RGB channel, 5-6 h on Ha and 1.5h on O3. Here is the result:
Then I asked myself if I should shoot L, more RGB, more narrowband or if I should go for another target. And I decided that I should try a mosaic in this area and catch the lobster claw too.
The decision being took, I went below, left and then above again for panels 2, 3 and 4. R first, some of the G after. The rest of G and the B the next night. Last night I also shot 45 minutes of O3 on each of the remaining panels - 2, 3 and 4 and planning to shoot another 45 minutes on each panel the following nights, if possible. I will then leave the country for 2 weeks and I'll be back with a full moon when I will try to shoot some Ha. There will be no much time left either for this target as it reaches the limits where I can point my telescope from my balcony.
I'm aiming for 1.5-2h of O3 on each panel and 2-3h of Ha this year.
Supposing the acquisition can be done, I still have to stitch/process/stitch/combine all the layers.
Now, this is something I've never done before and I don't know which is the best approach.
I tried yesterday the new APP, I threw at him all the R subs and asked it to combine them in a mosaic way or a normal way. In mosaic it was failing with a null pointer exception and in normal way it was failing with an index out of bounds exception. So I answered myself an older question if I should wait for the APP or buy Registar and I bought the second after the first one didn't work.
I registered and stacked with DSS all the R, G, B and O3 frames for each panel with the best R frames set as reference.
Then I processed with StarTools each panel as RGB with the same settings and combined the RGB panels with Registar. Now this gave me a result which is almost ok, but you can see a separation line or two between panels 1 and 2 (the one with the bubble and the one below).
I processed each O3 layer with StarTools applying the same settings and I combined these too with Registar. Then I split the RGB mosaic into channels and I added the O3 over the G and B channels as lighten only in GIMP and I combined back again the layers into an RGB image. I colour balanced and enhanced this result in StarTools. The result is attached.
What do you think about my workflow and what approach did you find the best and how do you do it? Also, how can I normalize the layers and still be sure that I stretched them the same? There are some variables that come into play, the worsts mostly because during multiple nights I have different transparency and seeing conditions.
Many thanks and clear skies,
PS. and an annotated version: http://nova.astrometry.net/user_images/1668494#annotated
This image may compete for being one of the worst framings ever.
It is an RGB image that I processed from free data from the Liverpool Telescope, a 2 m RC reflector on La Palma. This time with quite a lot of data, so not much noise and a lot of detail. The "only" problem is that the astronomers requesting the subs must only have cared about NGC 3187 and the beautiful NGC 3190 just happened to be partly included.
Found this nice info about these galaxes on the Canary Islands Astronomical Institute www.iac.es:
Discovered by Sir William Herschel in 1784, NGC 3190 and NGC 3187 are two spiral galaxies seen nearly edge-on. The spiral arms of NGC 3190 are tightly wrapped around its nucleus, and those of NGC 3187 are S-shaped. Both galaxies are located in the constellation Leo and are members of the Hickson 44 galaxy group, located about 70 million light years from Earth. The galaxies in this group are very close to each other so that gravitational interactions are common, resulting in a high degree of shape distortion and a high rate of star formation in many cases. This gravitational dance will eventually end up in many galaxy mergers.
Filters and exposures used (from 2015 01 21 - 2016 04 26).
sdss-r 40 x 90 s (red channel)
Bessell V 23 x 90 s (green channel)
Bessell B + sdss-g 53 x 90 s (blue channel)
As @wimvb just said, we are going through the Liverpool Telescope database - a largely unused treasure chest of deep sky data. What else could Swedes do when it is light enough to read a paper outdoors at midnight? Taken together we have done close to 50 images up to now.
When I processed this image I had no idea what it was. I found the subs in the data base with the cryptic name "bd65_1637". Only after uploading it on Astrobin, plate solving told me it was NGC 7129.
NGC 7129 is a reflection nebula located 3,300 light years away in the constellation Cepheus. A young open cluster is responsible for illuminating the surrounding nebula. A recent survey indicates the cluster contains more than 130 stars less than 1 million years old [all according to Wikipedia]
Filters and Exposures used:
sdss- r 15 x 90 s
Ha 9 x 120 s (stacked 40:60 with sdss-r for red channel)
Bessell B 14 x 90 s (blue channel)
Bessell V 13 x 90 s (green channel)
The scope is a 2 m RC on La Palma
@gorann and I are keeping ourselves busy ploughing through the Liverpool Telescope archives. Every now and then we find some hidden gems in this treasure chest. Here's one that was somewhat of a challenge.
NGC 5383 is a barred spiral galaxy in the constellation Canes Venatici. The central part of the galaxy is some 3 arcminutes in diameter. But the interesting features are outside of this. The spiral arms extend well beyond double this diameter. This is rarely revealed in images.