#1
|
|||
|
|||
ASTRO: Arp 304
Arp 304 consists of two galaxies NGC 1241 and NGC 1242, right to left
and a double star to the southeast, NGC 1243. The two galaxies were first seen by William Herschel. John Herschel, unable to see 1242 recorded the double star. Dreyer saw all three but recorded the double star as a nebula. It seems odd that even with a 72" scope (speculum mirror I assume) he couldn't recognize 2 14th magnitude stars 12" apart. The NGC is full of such mistakes, some single stars. The pair is about 175 to 178 million light years distant in the constellation of Eridanus. Arp put them in his catalog under double galaxies with filaments. I suppose that is the northward arm of NGC 1241. While red shift puts them at about the same distance there's some question about whether they are interacting or not. One note at NED says no, another yes and another wanted more data. NED classes NGC 1241 as SB(rs)b Sy2, NGC 1242 as SB(rs)c:. NGC 1241 does have that odd arm and NGC 1242 seems odd with that very blue northern arm and one heavy arm. So I vote for the interaction being possible. Still there are no real plumes which is likely why others say no interaction. The field is out of the Sloan Survey coverage. Only one other galaxy in my field has a known red shift. To find it look well east (left) and a bit south (down) of Arp 304. It is the largest red round galaxy. Further east is a close rather bright double star with a blue galaxy above it. The red one is 2MASX J03121399-0858394 at 1.3 billion light years. The blue one is APMUKS(BJ) B030959.78-090917.2. Other than it being magnitude 18.15 there's no data on it or any other galaxy in the image. But there is one asteroid 2005 LZ45 at magnitude 19.8 shows up as a short streak angling slightly upward west of the bottom end of NGC 1241. It is at the edge of the 150% crop image above a slightly orange star that's the first up from the bottom right corner of the cropped image. This is my last November image (maybe not -- I just found another lost on the hard drive but with weak maybe unusable green data). Now I can move to December. December was mostly cloudy. Only one clear night and it lasted only half the night so only 3 images for that month (well 4, as I found a lost one there too with weak color data that I may be able to salvage). Soon I'll be processing 2010 images! Arp's image http://nedwww.ipac.caltech.edu/level...ig_arp304.jpeg 14" LX200R @ f/10, L=4x10' RGB=2x10'x3, 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
|
|||
|
|||
ASTRO: Arp 304
Another good image.
Is your filter set IR blocked? On Tue, 05 Oct 2010 20:12:29 -0500, Rick Johnson wrote: Arp 304 consists of two galaxies NGC 1241 and NGC 1242, right to left and a double star to the southeast, NGC 1243. The two galaxies were first seen by William Herschel. John Herschel, unable to see 1242 recorded the double star. Dreyer saw all three but recorded the double star as a nebula. It seems odd that even with a 72" scope (speculum mirror I assume) he couldn't recognize 2 14th magnitude stars 12" apart. The NGC is full of such mistakes, some single stars. The pair is about 175 to 178 million light years distant in the constellation of Eridanus. Arp put them in his catalog under double galaxies with filaments. I suppose that is the northward arm of NGC 1241. While red shift puts them at about the same distance there's some question about whether they are interacting or not. One note at NED says no, another yes and another wanted more data. NED classes NGC 1241 as SB(rs)b Sy2, NGC 1242 as SB(rs)c:. NGC 1241 does have that odd arm and NGC 1242 seems odd with that very blue northern arm and one heavy arm. So I vote for the interaction being possible. Still there are no real plumes which is likely why others say no interaction. The field is out of the Sloan Survey coverage. Only one other galaxy in my field has a known red shift. To find it look well east (left) and a bit south (down) of Arp 304. It is the largest red round galaxy. Further east is a close rather bright double star with a blue galaxy above it. The red one is 2MASX J03121399-0858394 at 1.3 billion light years. The blue one is APMUKS(BJ) B030959.78-090917.2. Other than it being magnitude 18.15 there's no data on it or any other galaxy in the image. But there is one asteroid 2005 LZ45 at magnitude 19.8 shows up as a short streak angling slightly upward west of the bottom end of NGC 1241. It is at the edge of the 150% crop image above a slightly orange star that's the first up from the bottom right corner of the cropped image. This is my last November image (maybe not -- I just found another lost on the hard drive but with weak maybe unusable green data). Now I can move to December. December was mostly cloudy. Only one clear night and it lasted only half the night so only 3 images for that month (well 4, as I found a lost one there too with weak color data that I may be able to salvage). Soon I'll be processing 2010 images! Arp's image http://nedwww.ipac.caltech.edu/level...ig_arp304.jpeg 14" LX200R @ f/10, L=4x10' RGB=2x10'x3, STL-11000XM, Paramount ME Rick |
#3
|
|||
|
|||
ASTRO: Arp 304
Yes. I debated long and hard when getting my new set of LRGB filters.
The corrector of the scope isn't fully blue corrected (single lens) and had heard the blue halos that gives were worse with a clear due to near UV. Also I hope to add a wide field refractor and that would require an L filter. Still when I feel rich again, I may buy just a C and give it a try. The 11000 chip is very weak in IR so probably wouldn't add as much as it would with a different chip however. Rick On 10/6/2010 1:17 PM, glen youman wrote: Another good image. Is your filter set IR blocked? |
#4
|
|||
|
|||
ASTRO: Arp 304
Very good image of this pair (that I wasn't aware of before).
Have you changed your image processing procedure recently? It seems to me that you are showing more noise in the fainter parts than you used to. Stefan "Rick Johnson" schrieb im Newsbeitrag ster.com... Arp 304 consists of two galaxies NGC 1241 and NGC 1242, right to left and a double star to the southeast, NGC 1243. The two galaxies were first seen by William Herschel. John Herschel, unable to see 1242 recorded the double star. Dreyer saw all three but recorded the double star as a nebula. It seems odd that even with a 72" scope (speculum mirror I assume) he couldn't recognize 2 14th magnitude stars 12" apart. The NGC is full of such mistakes, some single stars. The pair is about 175 to 178 million light years distant in the constellation of Eridanus. Arp put them in his catalog under double galaxies with filaments. I suppose that is the northward arm of NGC 1241. While red shift puts them at about the same distance there's some question about whether they are interacting or not. One note at NED says no, another yes and another wanted more data. NED classes NGC 1241 as SB(rs)b Sy2, NGC 1242 as SB(rs)c:. NGC 1241 does have that odd arm and NGC 1242 seems odd with that very blue northern arm and one heavy arm. So I vote for the interaction being possible. Still there are no real plumes which is likely why others say no interaction. The field is out of the Sloan Survey coverage. Only one other galaxy in my field has a known red shift. To find it look well east (left) and a bit south (down) of Arp 304. It is the largest red round galaxy. Further east is a close rather bright double star with a blue galaxy above it. The red one is 2MASX J03121399-0858394 at 1.3 billion light years. The blue one is APMUKS(BJ) B030959.78-090917.2. Other than it being magnitude 18.15 there's no data on it or any other galaxy in the image. But there is one asteroid 2005 LZ45 at magnitude 19.8 shows up as a short streak angling slightly upward west of the bottom end of NGC 1241. It is at the edge of the 150% crop image above a slightly orange star that's the first up from the bottom right corner of the cropped image. This is my last November image (maybe not -- I just found another lost on the hard drive but with weak maybe unusable green data). Now I can move to December. December was mostly cloudy. Only one clear night and it lasted only half the night so only 3 images for that month (well 4, as I found a lost one there too with weak color data that I may be able to salvage). Soon I'll be processing 2010 images! Arp's image http://nedwww.ipac.caltech.edu/level...ig_arp304.jpeg 14" LX200R @ f/10, L=4x10' RGB=2x10'x3, 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". |
#5
|
|||
|
|||
ASTRO: Arp 304
I'll have to blame the cataracts which were exploding when this was
processed. One eye has been fixed but I have no close vision until a month after the other eye is fixed. It is useless right now and patched as all it sees is light fuzz. Reading glasses help see close but don't correct my severe astigmatism so until fitted for real glasses sometime in December I'm running more than half blind. I usually only process noise to where it doesn't bother me. Now, of course, I only see it if really bad. I'll likely be reprocessing these once I can see again. Color is another issue now as my brain compensated for a strong sepia color shift. Now the world is day glow blue. It's as if my tint control was full blue shifted. Until my brain finds its white balance control color will likely be off as well. I'm just processing by the numbers now as I can't trust what I see to tweak it any. Rick On 10/17/2010 4:12 PM, Stefan Lilge wrote: Very good image of this pair (that I wasn't aware of before). Have you changed your image processing procedure recently? It seems to me that you are showing more noise in the fainter parts than you used to. Stefan "Rick schrieb im Newsbeitrag ster.com... Arp 304 consists of two galaxies NGC 1241 and NGC 1242, right to left and a double star to the southeast, NGC 1243. The two galaxies were first seen by William Herschel. John Herschel, unable to see 1242 recorded the double star. Dreyer saw all three but recorded the double star as a nebula. It seems odd that even with a 72" scope (speculum mirror I assume) he couldn't recognize 2 14th magnitude stars 12" apart. The NGC is full of such mistakes, some single stars. The pair is about 175 to 178 million light years distant in the constellation of Eridanus. Arp put them in his catalog under double galaxies with filaments. I suppose that is the northward arm of NGC 1241. While red shift puts them at about the same distance there's some question about whether they are interacting or not. One note at NED says no, another yes and another wanted more data. NED classes NGC 1241 as SB(rs)b Sy2, NGC 1242 as SB(rs)c:. NGC 1241 does have that odd arm and NGC 1242 seems odd with that very blue northern arm and one heavy arm. So I vote for the interaction being possible. Still there are no real plumes which is likely why others say no interaction. The field is out of the Sloan Survey coverage. Only one other galaxy in my field has a known red shift. To find it look well east (left) and a bit south (down) of Arp 304. It is the largest red round galaxy. Further east is a close rather bright double star with a blue galaxy above it. The red one is 2MASX J03121399-0858394 at 1.3 billion light years. The blue one is APMUKS(BJ) B030959.78-090917.2. Other than it being magnitude 18.15 there's no data on it or any other galaxy in the image. But there is one asteroid 2005 LZ45 at magnitude 19.8 shows up as a short streak angling slightly upward west of the bottom end of NGC 1241. It is at the edge of the 150% crop image above a slightly orange star that's the first up from the bottom right corner of the cropped image. This is my last November image (maybe not -- I just found another lost on the hard drive but with weak maybe unusable green data). Now I can move to December. December was mostly cloudy. Only one clear night and it lasted only half the night so only 3 images for that month (well 4, as I found a lost one there too with weak color data that I may be able to salvage). Soon I'll be processing 2010 images! Arp's image http://nedwww.ipac.caltech.edu/level...ig_arp304.jpeg 14" LX200R @ f/10, L=4x10' RGB=2x10'x3, 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". -- Correct domain name is arvig and it is net not com. Prefix is correct. Third character is a zero rather than a capital "Oh". |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
[sci.astro,sci.astro.seti] Contents (Astronomy Frequently Asked Questions) (0/9) | [email protected] | SETI | 0 | August 15th 07 09:36 PM |
[sci.astro,sci.astro.seti] Contents (Astronomy Frequently Asked Questions) (0/9) | [email protected] | Astronomy Misc | 0 | May 3rd 07 01:08 AM |
[sci.astro,sci.astro.seti] Contents (Astronomy Frequently Asked Questions) (0/9) | [email protected] | SETI | 0 | May 3rd 07 01:08 AM |
[sci.astro,sci.astro.seti] Contents (Astronomy Frequently Asked Questions) (0/9) | [email protected] | Astronomy Misc | 0 | May 3rd 06 12:33 PM |
[sci.astro,sci.astro.seti] Contents (Astronomy Frequently Asked Questions) (0/9) | [email protected] | SETI | 0 | May 3rd 06 12:33 PM |