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ASTRO: NGC 2340 et al
I've been without internet access for a few days. so catching up on my
posting. Of course the outage began the morning of Friday the 13th. ________ NGC 2340 is the largest and brightest member of the WBL 133 galaxy group located about 275 million light-years away in the constellation of Lynx and not far from the far larger Abell 569. The group contains some 13 members though not all are withing my image. I should have moved 2340 from the center to capture more of them but this was taken automatically as I slept so the scope just obeyed my instructions to center on 2340. As with most groups the members are mostly elliptical and S0 galaxies and thus showing the golden color of old stars due to the lack of new star formation. Apparently these galaxies have so interacted with other members of the group that the dust and gas needed for star formation has been stripped from them leaving them to slowly redden and fade away. The spherical galaxy to the upper left of NGC 2340 is IC 465 and maybe also NGC 2334. Why the "maybe"? Seems there's lots of problems with the visual observations that created the NGC catalog. This is one of them. Since the catalog is numbered in RA order (at the time of the catalog, precession has changed things somewhat since then when looking at galaxies today on opposite sides of the sky) it should be west of NGC 2340 not east. This is the first hint that something may be wrong. For further information I'll refer you to Dr. Corwin's discussion at the NGC catalog. http://www.ngcicproject.org/dss/dss_n2300.asp Scroll down to NGC 2334 and click on the data button then scroll down that window for the lengthy discussion. The large elliptical near the right edge nearly directly west of NGC 2340 is NGC 2332. Below it is IC 457 which may or may not be NGC 2330. This problem is included in the lengthy discussion of IC 465/NGC 2334 in the above link. I've made an annotated image showing member galaxies as well as a few non member ones. If they are a member no distance is given. If a non member the distance in millions of light-years is appended to the name. Some have no red shift data so are noted with a ? for distance. There are some other ID problems in this image. IC 462 is just a blue star. Could it be the observer saw the nearby galaxy but got the position of the star by mistake? I can't find anything on this one. Then there's the blue object I've identified as [VCV2001] J071006.8+500245 at almost 2 billion light-years. NED shows many different catalog entries for it. One, the one I used, says it is a quasar, one of the closest known. Another calls it a galaxy (RX J0710.0+5002 ID) as well as an X-ray source. It's shown as an IR source in the 2MASS catalog (2MASSi J0710068+500246). It is also listed in several radio catalogs. It certainly is using most of the spectrum. Due to its strong blue color, typical of "nearby" quasars I chose to go with the quasar designation. 14" LX200R @ f/10, L=4x10' RGB=2x10', 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". |
#2
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ASTRO: NGC 2340 et al
On Tue, 17 Nov 2009 12:54:29 -0600, Rick Johnson
wrote: I've been without internet access for a few days. so catching up on my posting. Of course the outage began the morning of Friday the 13th. My bad. The 13th was my birthday; the internet and I went out and got ~really~ drunk... Sorry about that. |
#3
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ASTRO: NGC 2340 et al
Rick,
you got a lot of galaxies in this frame. I always find it remarkable that you get good colour even for the faint parts of the image. Stefan "Rick Johnson" schrieb im Newsbeitrag om... I've been without internet access for a few days. so catching up on my posting. Of course the outage began the morning of Friday the 13th. ________ NGC 2340 is the largest and brightest member of the WBL 133 galaxy group located about 275 million light-years away in the constellation of Lynx and not far from the far larger Abell 569. The group contains some 13 members though not all are withing my image. I should have moved 2340 from the center to capture more of them but this was taken automatically as I slept so the scope just obeyed my instructions to center on 2340. As with most groups the members are mostly elliptical and S0 galaxies and thus showing the golden color of old stars due to the lack of new star formation. Apparently these galaxies have so interacted with other members of the group that the dust and gas needed for star formation has been stripped from them leaving them to slowly redden and fade away. The spherical galaxy to the upper left of NGC 2340 is IC 465 and maybe also NGC 2334. Why the "maybe"? Seems there's lots of problems with the visual observations that created the NGC catalog. This is one of them. Since the catalog is numbered in RA order (at the time of the catalog, precession has changed things somewhat since then when looking at galaxies today on opposite sides of the sky) it should be west of NGC 2340 not east. This is the first hint that something may be wrong. For further information I'll refer you to Dr. Corwin's discussion at the NGC catalog. http://www.ngcicproject.org/dss/dss_n2300.asp Scroll down to NGC 2334 and click on the data button then scroll down that window for the lengthy discussion. The large elliptical near the right edge nearly directly west of NGC 2340 is NGC 2332. Below it is IC 457 which may or may not be NGC 2330. This problem is included in the lengthy discussion of IC 465/NGC 2334 in the above link. I've made an annotated image showing member galaxies as well as a few non member ones. If they are a member no distance is given. If a non member the distance in millions of light-years is appended to the name. Some have no red shift data so are noted with a ? for distance. There are some other ID problems in this image. IC 462 is just a blue star. Could it be the observer saw the nearby galaxy but got the position of the star by mistake? I can't find anything on this one. Then there's the blue object I've identified as [VCV2001] J071006.8+500245 at almost 2 billion light-years. NED shows many different catalog entries for it. One, the one I used, says it is a quasar, one of the closest known. Another calls it a galaxy (RX J0710.0+5002 ID) as well as an X-ray source. It's shown as an IR source in the 2MASS catalog (2MASSi J0710068+500246). It is also listed in several radio catalogs. It certainly is using most of the spectrum. Due to its strong blue color, typical of "nearby" quasars I chose to go with the quasar designation. 14" LX200R @ f/10, L=4x10' RGB=2x10', 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 2340 et al
Stefan Lilge wrote:
Rick, you got a lot of galaxies in this frame. I always find it remarkable that you get good colour even for the faint parts of the image. Stefan Probably due to my very dark skies here. Population density in this area is about 1 per square mile. Forest blocks nearly all light from them reaching the sky. 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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