|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
ASTRO: NGC 3367 and NGC 3377 with some of its globular star clusters
NGC 3367 is a rather messed up barred spiral in Leo north of M105 about 150 million light-years away. To show so much detail at that distance you know it is large, about 115,000 light-years across by my measurements including the faint outer plume on the western side. I say "messed up" due to its rather chaotic spiral structure. At first glance it looks rather normal but then you find arms start from nothing or branch from others. One ends when it hits a bright edge that appears to be a spiral arm that comes from nowhere. It has one heavy arm on the south side that certainly fits Arp's "One heavy arm" category though didn't make his list. As I was about to start the image I noted there was a rather large NGC galaxy in The Sky just outside the field of view. I decided to include it so moved NGC 3367 down and west just enough to bring NGC 3377 into the image. Good thing as it turned out quite interesting though wasn't on my to-do list. It is a large "discy" elliptical galaxy much closer than NGC 3367. Redshift puts it at 47 million light-years but a bunch of non redshift measurements have a median value of 35 million light-years. Considering how many globular clusters I was able to find in it I'll go with that closer figure. By "discy" I mean it appears to have a disc like structure inside the elliptical structure. One note at NED agrees and another says there's no hint of a disc. I pointed out some of the globular clusters close to the galaxy though NED listed a lot more further out and seen against the galaxy. Some of the latter weren't even visible in the Sloan image. NED also listed a hundred or more planetary nebulae. After finding some in M31 I looked for them in my image. After not finding them I checked the SLOAN image and couldn't identify any their either. I only tested a half dozen out of more than 100 so a few might be faintly seen. Figuring if SLOAN can't see the ones I checked there was little likelihood I would. The NED data also included many stars also listed a candidate QSO along with some UvS objects also listed as QSO candidates. Like before some of the stars turned out to be rejected QSOs but none of the UvS objects were rejected. So like before I included the UvS objects but not the stars listed also a QSO candidates. Again there were many dozen of these, far too many to note without making a mess of the annotated image. I suspect either we are severely underestimating the quasars in the universe or, more likely, most of these are really just stars that for some reason show high photographic redshift. Like before none had spectroscopic redshifts. Those that did are marked as being QSOs by NED and on my annotated image. One rather bright asteroid photo bombed the image. Usually one this bright has a common name but this one only has its discovery sequence ID. 14" LX200R @ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME Rick -- Prefix is correct. Domain is arvig dot net |
#2
|
|||
|
|||
ASTRO: NGC 3367 and NGC 3377 with some of its globular star clusters
Mighty image Rick. NGC 3367 is one of my favourites.
Stefan "Rick Johnson" schrieb im Newsbeitrag om... NGC 3367 is a rather messed up barred spiral in Leo north of M105 about 150 million light-years away. To show so much detail at that distance you know it is large, about 115,000 light-years across by my measurements including the faint outer plume on the western side. I say "messed up" due to its rather chaotic spiral structure. At first glance it looks rather normal but then you find arms start from nothing or branch from others. One ends when it hits a bright edge that appears to be a spiral arm that comes from nowhere. It has one heavy arm on the south side that certainly fits Arp's "One heavy arm" category though didn't make his list. As I was about to start the image I noted there was a rather large NGC galaxy in The Sky just outside the field of view. I decided to include it so moved NGC 3367 down and west just enough to bring NGC 3377 into the image. Good thing as it turned out quite interesting though wasn't on my to-do list. It is a large "discy" elliptical galaxy much closer than NGC 3367. Redshift puts it at 47 million light-years but a bunch of non redshift measurements have a median value of 35 million light-years. Considering how many globular clusters I was able to find in it I'll go with that closer figure. By "discy" I mean it appears to have a disc like structure inside the elliptical structure. One note at NED agrees and another says there's no hint of a disc. I pointed out some of the globular clusters close to the galaxy though NED listed a lot more further out and seen against the galaxy. Some of the latter weren't even visible in the Sloan image. NED also listed a hundred or more planetary nebulae. After finding some in M31 I looked for them in my image. After not finding them I checked the SLOAN image and couldn't identify any their either. I only tested a half dozen out of more than 100 so a few might be faintly seen. Figuring if SLOAN can't see the ones I checked there was little likelihood I would. The NED data also included many stars also listed a candidate QSO along with some UvS objects also listed as QSO candidates. Like before some of the stars turned out to be rejected QSOs but none of the UvS objects were rejected. So like before I included the UvS objects but not the stars listed also a QSO candidates. Again there were many dozen of these, far too many to note without making a mess of the annotated image. I suspect either we are severely underestimating the quasars in the universe or, more likely, most of these are really just stars that for some reason show high photographic redshift. Like before none had spectroscopic redshifts. Those that did are marked as being QSOs by NED and on my annotated image. One rather bright asteroid photo bombed the image. Usually one this bright has a common name but this one only has its discovery sequence ID. 14" LX200R @ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME Rick -- Prefix is correct. Domain is arvig dot net |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Star Clusters Globular Clusters Dwarf Galaxies | G=EMC^2[_2_] | Misc | 6 | August 30th 12 08:15 PM |
Complete list of known globular clusters, MW star clouds? | [email protected] | Amateur Astronomy | 2 | January 19th 09 06:00 PM |
ASTRO: M110 with Globular Clusters identified | Rick Johnson[_3_] | Astro Pictures | 1 | February 8th 08 10:21 PM |
Star Party Presentation Cheat Sheet - Older Low-Metallicity Globular Clusters for Aug Sept | canopus56[_1_] | Amateur Astronomy | 0 | September 14th 07 06:37 AM |
Globular clusters and Star collissions | 46erjoe | Misc | 4 | November 7th 06 04:00 AM |