#1
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ASTRO: NGC 6412
NGC 6412 in Draco is a nice target for early summer, I imaged it in two
nights in June. Taken from the middle of Berlin with a 10" Meade ACF at f/5.7 on a G11 mount, SXV-H9 camera, 52x5 minutes for L and 6x5 minutes each for RGB. The picture can also be found at http://ccd-astronomy.de/temp/6412colourgut.jpg b/w version at http://ccd-astronomy.de/temp/6412-52x5gut.jpg Stefan |
#2
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ASTRO: NGC 6412
Hi Stephan; Very nice image, especially since your in the center of an urban light polluted area. Do you use a Light Pollution Filter when imaging? And what sort of limiting visual magnitude do you get at your imaging site in Berlin? Thanks in advance.. Milton Aupperle http://www.outcastsoft.com/AstroImages/AstroIndex.html In article , Stefan Lilge wrote: NGC 6412 in Draco is a nice target for early summer, I imaged it in two nights in June. Taken from the middle of Berlin with a 10" Meade ACF at f/5.7 on a G11 mount, SXV-H9 camera, 52x5 minutes for L and 6x5 minutes each for RGB. The picture can also be found at http://ccd-astronomy.de/temp/6412colourgut.jpg b/w version at http://ccd-astronomy.de/temp/6412-52x5gut.jpg Stefan begin 666 6412colourgut.jpg |
#3
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ASTRO: NGC 6412
Thanks Milton.
I don't use light pollution filters for galaxies, because after some years of trying different models I came to the conclusion that they don't make sense for the kind of "broadband" light pollution I have. They can be useful if you have a special kind of light pollution (e.g. some sorts of streetlights) that cause "narrowband" light pollution. I once found a chain of streetlights near a town in northern germany that was almost totally "eliminated" by an Astronomik CLS filter, while it only dims starlight by a factor of about two. So if I would image near these streetlights, using the Astronomik CLS would make sense. As for the limiting magnitude I don't "believe" in using the human eye for measuring sky brightness. Limiting mag is as much dependend on one's eyesight as on the actual brightness of the sky. I have often seen claims of people who live in small towns that they have "mag 3.5 skies at best". I can only guess that they have bad eyes or are setting up their scopes directly under a lantern as I can see mag 4.5 stars near zenith from the central part of a large city. One thing I can safely say is that I can never, not even in the nights with the best transparency, see any hint of the milky way. I can quantify the light pollution with my CCD camera: With my 10" Meade ACF at f/5.7 and my SXV-H9 camera I got almost exactly 1000 counts background in 5 minutes under decent skies this spring while I got almost exactly 14000 with the same setup under my Berlin skies a few days later in a night with good transparency. So my city skies are about 14 times brighter than "decent" skies. Stefan "Milton Aupperle" schrieb im Newsbeitrag ... Hi Stephan; Very nice image, especially since your in the center of an urban light polluted area. Do you use a Light Pollution Filter when imaging? And what sort of limiting visual magnitude do you get at your imaging site in Berlin? Thanks in advance.. Milton Aupperle http://www.outcastsoft.com/AstroImages/AstroIndex.html In article , Stefan Lilge wrote: NGC 6412 in Draco is a nice target for early summer, I imaged it in two nights in June. Taken from the middle of Berlin with a 10" Meade ACF at f/5.7 on a G11 mount, SXV-H9 camera, 52x5 minutes for L and 6x5 minutes each for RGB. The picture can also be found at http://ccd-astronomy.de/temp/6412colourgut.jpg b/w version at http://ccd-astronomy.de/temp/6412-52x5gut.jpg Stefan begin 666 6412colourgut.jpg |
#4
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ASTRO: NGC 6412
Stefan Lilge wrote: NGC 6412 in Draco is a nice target for early summer, I imaged it in two nights in June. Taken from the middle of Berlin with a 10" Meade ACF at f/5.7 on a G11 mount, SXV-H9 camera, 52x5 minutes for L and 6x5 minutes each for RGB. The picture can also be found at http://ccd-astronomy.de/temp/6412colourgut.jpg b/w version at http://ccd-astronomy.de/temp/6412-52x5gut.jpg Stefan That's one that escaped my to-do list, just too far north and thus in my Polaris tree. Though at its 75 degree declination there is a small hole that lasts for about 15-20 minutes. I've used it once and now realize I never posted that shot. Seems I never timed it quite right and the field moved into a few sparse needles on the pine which really added "interesting" diffraction patterns to the stars. To use that hole I have to catch the object about 7 hours before it reaches the meridian or 5 after it passes lower culmination. No easy to remember to do. Lots of faint fuzzies in the background as well. Rick -- Correct domain name is arvig and it is net not com. Prefix is correct. Third character is a zero rather than a capital "Oh". |
#5
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ASTRO: NGC 6412
Very nice Stefan!
Stefan Lilge wrote: NGC 6412 in Draco is a nice target for early summer, I imaged it in two nights in June. Taken from the middle of Berlin with a 10" Meade ACF at f/5.7 on a G11 mount, SXV-H9 camera, 52x5 minutes for L and 6x5 minutes each for RGB. The picture can also be found at http://ccd-astronomy.de/temp/6412colourgut.jpg b/w version at http://ccd-astronomy.de/temp/6412-52x5gut.jpg Stefan -- John N. Gretchen III http://www.tisd.net/~jng3 |
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