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#1
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ASTRO: NGC 1169
Many wide field photos of Comet Holmes showed a tiny fuzz patch that I
tracked down as NGC 1169. I decided to try an image it. The galaxy itself turned out interesting and there were lots of interesting galaxies in the area. I like the 4 to the upper right. 4 are nice thin spirals and one face on. The three thin guys from bottom to top are UGC 02496 at 300 MLY, LEDA 213150 at 528 MLY and LEDA 213153 at an unknown distance. I found no info on the distance to any of the others. The face on in this group of apparently unrelated galaxies is LEDA 213151 The barred spiral just above and left of 1169 is AGC 130456 Above it near the top is AGC 130457 The only other one I bothered to look up is the one at the far right below center It has a mouthful of a name HFLLBZOA K547 HFLLBZOA stands for Hav, Ferguson, Lahav, Lynden, Bell Zone of Avoidance Galaxies. NGC 1169 is at about 100 million light years so is a rather large galaxy. Though its spiral arms are yellow rather than blue so little star formation has been going on. I see a hint of blue around the very outer edges of the arms but otherwise this is a pretty sedate galaxy it would seem. Rather interesting barred spiral structure however. The visual NGC description is: Very small, bright nucleus close to a star; Very faint (r): 0.95 arcmin x 0.6 arcmin. Several very faint filamentary arms. Very low surface brightness. 14" LX200R @ f/10, L=8x5' RGB=3x5', STL-11000XM, Paramount ME 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". |
#3
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ASTRO: NGC 1169
What a nice FOV Rick... really shows the small galaxies. I have the same
shot, more or less, with 150 min. of grayscale and it shows about the same detail. My shot was done in Nov. 06 and it looks as though the seeing was not very good... should try it again if I get a chance. At our FL the galaxy is good size in the frame. -- Regards, Doug W. www.photonsfate.com "Rick Johnson" wrote in message ... Many wide field photos of Comet Holmes showed a tiny fuzz patch that I tracked down as NGC 1169. I decided to try an image it. The galaxy itself turned out interesting and there were lots of interesting galaxies in the area. I like the 4 to the upper right. 4 are nice thin spirals and one face on. The three thin guys from bottom to top are UGC 02496 at 300 MLY, LEDA 213150 at 528 MLY and LEDA 213153 at an unknown distance. I found no info on the distance to any of the others. The face on in this group of apparently unrelated galaxies is LEDA 213151 The barred spiral just above and left of 1169 is AGC 130456 Above it near the top is AGC 130457 The only other one I bothered to look up is the one at the far right below center It has a mouthful of a name HFLLBZOA K547 HFLLBZOA stands for Hav, Ferguson, Lahav, Lynden, Bell Zone of Avoidance Galaxies. NGC 1169 is at about 100 million light years so is a rather large galaxy. Though its spiral arms are yellow rather than blue so little star formation has been going on. I see a hint of blue around the very outer edges of the arms but otherwise this is a pretty sedate galaxy it would seem. Rather interesting barred spiral structure however. The visual NGC description is: Very small, bright nucleus close to a star; Very faint (r): 0.95 arcmin x 0.6 arcmin. Several very faint filamentary arms. Very low surface brightness. 14" LX200R @ f/10, L=8x5' RGB=3x5', STL-11000XM, Paramount ME 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". |
#4
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ASTRO: NGC 1169
Doug W. wrote: What a nice FOV Rick... really shows the small galaxies. I have the same shot, more or less, with 150 min. of grayscale and it shows about the same detail. My shot was done in Nov. 06 and it looks as though the seeing was not very good... should try it again if I get a chance. At our FL the galaxy is good size in the frame. I'd totally forgotten your post. I see your "not very good" seeing is better than mine as I was unable to separate the star from the nucleus. Though I didn't realize it was there. I will have to go back and see if I can separate it out. Doubt it. My seeing this winter has been running 4.5". Last year it was 3.2. A big difference. Not sure why the change. 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 1169
Very good picture Rick, and an interesting galaxy that I have not imaged
yet. Stefan "Rick Johnson" schrieb im Newsbeitrag ... Doug W. wrote: What a nice FOV Rick... really shows the small galaxies. I have the same shot, more or less, with 150 min. of grayscale and it shows about the same detail. My shot was done in Nov. 06 and it looks as though the seeing was not very good... should try it again if I get a chance. At our FL the galaxy is good size in the frame. I'd totally forgotten your post. I see your "not very good" seeing is better than mine as I was unable to separate the star from the nucleus. Though I didn't realize it was there. I will have to go back and see if I can separate it out. Doubt it. My seeing this winter has been running 4.5". Last year it was 3.2. A big difference. Not sure why the change. 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". |
#6
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ASTRO: NGC 1169
nice image Rick and a very galaxy loaded FOV
I was curious about your histograms: the black background looked pretty clipped to me when I loaded your image into maxim to take a look at it, this is what I saw as you can see it is clipped on both ends. On the left end a close look in photoshop revealed the blue channel was clipped on the left side but the red and green were not the right side is clipped in all channels. The right or bright side clipping causes star saturation, flat topping and a loss of the "shape" of the star. It also turns those that saturate white. The left side or dark side clipping causes loss of faint nebulosity, and of course the sky really isn't black. I think if you worked on it a bit you could get histograms looking more like this, and in doing so I believe your images will have a better appearance You have a lot of good data but I think the clipped histograms are detracting from the potential of your data. it is a subtle point but getting to the next level involves pulling together more subtle aspects of the processing flow. "Rick Johnson" wrote in message ... Many wide field photos of Comet Holmes showed a tiny fuzz patch that I tracked down as NGC 1169. I decided to try an image it. The galaxy itself turned out interesting and there were lots of interesting galaxies in the area. I like the 4 to the upper right. 4 are nice thin spirals and one face on. The three thin guys from bottom to top are UGC 02496 at 300 MLY, LEDA 213150 at 528 MLY and LEDA 213153 at an unknown distance. I found no info on the distance to any of the others. The face on in this group of apparently unrelated galaxies is LEDA 213151 The barred spiral just above and left of 1169 is AGC 130456 Above it near the top is AGC 130457 The only other one I bothered to look up is the one at the far right below center It has a mouthful of a name HFLLBZOA K547 HFLLBZOA stands for Hav, Ferguson, Lahav, Lynden, Bell Zone of Avoidance Galaxies. NGC 1169 is at about 100 million light years so is a rather large galaxy. Though its spiral arms are yellow rather than blue so little star formation has been going on. I see a hint of blue around the very outer edges of the arms but otherwise this is a pretty sedate galaxy it would seem. Rather interesting barred spiral structure however. The visual NGC description is: Very small, bright nucleus close to a star; Very faint (r): 0.95 arcmin x 0.6 arcmin. Several very faint filamentary arms. Very low surface brightness. 14" LX200R @ f/10, L=8x5' RGB=3x5', STL-11000XM, Paramount ME 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". |
#7
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ASTRO: NGC 1169
Richard Crisp wrote: nice image Rick and a very galaxy loaded FOV I was curious about your histograms: the black background looked pretty clipped to me when I loaded your image into maxim to take a look at it, this is what I saw as you can see it is clipped on both ends. On the left end a close look in photoshop revealed the blue channel was clipped on the left side but the red and green were not the right side is clipped in all channels. The right or bright side clipping causes star saturation, flat topping and a loss of the "shape" of the star. It also turns those that saturate white. The left side or dark side clipping causes loss of faint nebulosity, and of course the sky really isn't black. I think if you worked on it a bit you could get histograms looking more like this, and in doing so I believe your images will have a better appearance You have a lot of good data but I think the clipped histograms are detracting from the potential of your data. it is a subtle point but getting to the next level involves pulling together more subtle aspects of the processing flow. "Rick Johnson" wrote in message ... Many wide field photos of Comet Holmes showed a tiny fuzz patch that I tracked down as NGC 1169. I decided to try an image it. The galaxy itself turned out interesting and there were lots of interesting galaxies in the area. I like the 4 to the upper right. 4 are nice thin spirals and one face on. The three thin guys from bottom to top are UGC 02496 at 300 MLY, LEDA 213150 at 528 MLY and LEDA 213153 at an unknown distance. I found no info on the distance to any of the others. The face on in this group of apparently unrelated galaxies is LEDA 213151 The barred spiral just above and left of 1169 is AGC 130456 Above it near the top is AGC 130457 The only other one I bothered to look up is the one at the far right below center It has a mouthful of a name HFLLBZOA K547 HFLLBZOA stands for Hav, Ferguson, Lahav, Lynden, Bell Zone of Avoidance Galaxies. NGC 1169 is at about 100 million light years so is a rather large galaxy. Though its spiral arms are yellow rather than blue so little star formation has been going on. I see a hint of blue around the very outer edges of the arms but otherwise this is a pretty sedate galaxy it would seem. Rather interesting barred spiral structure however. The visual NGC description is: Very small, bright nucleus close to a star; Very faint (r): 0.95 arcmin x 0.6 arcmin. Several very faint filamentary arms. Very low surface brightness. 14" LX200R @ f/10, L=8x5' RGB=3x5', STL-11000XM, Paramount ME 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". That's due to all the ice I was imaging through. Background is extremely noisy and irregular. Blue is by far the worst. The background is just one big mess of blobs. Rather than try and figure out a zillion gradients I just cut everything off. The high end is cut off due to another problem. It was too cold. I had to run at -50C to get stable temp control. Outside temp was -41C. At those temps there is an odd triangle shape to the stars caused by something in the camera. It does down with temp. The only way to get bright stars "round" is to cut off the bright so they fill in as saturated. Then they look round. It's a lesser of two evils situation. SBIG just says "That's weird -- image at warmer temps." Though they are again looking at the problem. There is a known problem with some versions of the camera doing this with the point going down. Mine goes to the right! Kodak says that can't happen. 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". |
#8
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ASTRO: NGC 1169
"Rick Johnson" wrote in message ... That's due to all the ice I was imaging through. Background is extremely noisy and irregular. Blue is by far the worst. The background is just one big mess of blobs. Rather than try and figure out a zillion gradients I just cut everything off. The high end is cut off due to another problem. It was too cold. I had to run at -50C to get stable temp control. Outside temp was -41C. At those temps there is an odd triangle shape to the stars caused by something in the camera. It does down with temp. The only way to get bright stars "round" is to cut off the bright so they fill in as saturated. Then they look round. It's a lesser of two evils situation. SBIG just says "That's weird -- image at warmer temps." Though they are again looking at the problem. There is a known problem with some versions of the camera doing this with the point going down. Mine goes to the right! Kodak says that can't happen. I use Russ Croman's Gradient Exterminator for solving my gradient problems. It works well enough that I haven't sought another tool. I use the plugin for Photoshop version. There's a bit of a learning curve as I find I have to interact with it to get the best results. Your camera problem is interesting to me. I can't say I am surprised that SBIG is clueless: they were clueless about RBI for many years and simply said "image at warmer temperatures" Well being a semiconductor guy with 30+ years experience designing integrated circuits, I find that to be a completely unacceptable answer; particularily from the self-appointed 'experts' Well as it turns out it is a pretty straightforward phenomenon caused by electron trapping sites in the silicon substrate at the interface between the Epitaxial layer and the bulk substrate. It is amazing to me that they were so ignorant and even more amazing that they apparently were happy to be ignorant instead of digging in and getting to the bottom of it. I'll post my analysis and conclusions separately. I'd like to know more about the cold temp problem: what else can you say about it from a symptom perspective? finally can you show me examples of it? I can setup an incoming FTP site so you can upload FIT data if you like. I thrive on diagnosing weird problems like that :-) |
#9
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ASTRO: NGC 1169
I spoke to a friend that works at a company that competes with SBIG about
your weird triangular shaped star issue. He wonders if your window to the camera is being distorted by the shrinking aluminum in the extreme cold? A similar potential issue could be the coverslip over the sensor: the ceramic package shrinks when it gets cold and the TCE of the coverslip may be different than the ceramic so it could potentially distort the coverslip and introduce astigmatism lastly the way the sensor is attached to the cold finger may be mechanically binding and as it gets even colder it could mechanically distort the ceramic package and its coverslip the distortion would normally cause astigmatism and if it is a rectangular arrangement as the coverslip shape is, then you could see some odd angles of the astigmatism I'd expect it on two axes for example. |
#10
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ASTRO: NGC 1169
Richard Crisp wrote: I spoke to a friend that works at a company that competes with SBIG about your weird triangular shaped star issue. He wonders if your window to the camera is being distorted by the shrinking aluminum in the extreme cold? A similar potential issue could be the coverslip over the sensor: the ceramic package shrinks when it gets cold and the TCE of the coverslip may be different than the ceramic so it could potentially distort the coverslip and introduce astigmatism lastly the way the sensor is attached to the cold finger may be mechanically binding and as it gets even colder it could mechanically distort the ceramic package and its coverslip the distortion would normally cause astigmatism and if it is a rectangular arrangement as the coverslip shape is, then you could see some odd angles of the astigmatism I'd expect it on two axes for example. I doubt it is a mechanical problem. Only happens with saturated stars. It gets less at 2x2 and nearly vanishes at 1x1 binning. It would appear worse at larger image scales if it were a mechanical problem. It has to be due to saturation but that normally causes a downward spike not one to the right. I should call it a snow cone (on its side) image rather than triangular. 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". |
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