ARP226

Arp 226/NGC 7252 is often known as the "Atoms for Peace" galaxy. It is considered to be a galaxy merger. It is about 200 to 220 million light-years away (depending on who you read -- 200 by redshift) and is located in the constellation of Aquarius, right along its southern border at -24 degrees. This puts it way too low for me to image. Over the lake atmospheric extinction is almost 2 magnitudes this low and I get severe chromatic smearing. Blue is weak that low as well making obtaining color data difficult. My color balance is very questionable this low as conditions change greatly between the time I take G2V calibration star and the image is complete. Doesn't help such stars aren't at that elevation. Higher up this is easy to but this low the standard formulas don't apply due to the humidity from the lake. I usually avoid going this low but as this is a famous galaxy, I had to give it a try. Many tries, that is. I started in July and finished in October with over 100 frames taken. The vast majority were too distorted, fuzzy, faint or otherwise unusable. This was a nightmare to piece together and far lower resolution than I'd like but considering how low it was it's about as good as I can hope to do. I had to use all the tricks in my bag to turn the streaks in the L frame to sort of round stars. Pure RGB would be better but didn't begin to have the frames for it.

The galaxy is thought to be the product of a collision of two spiral galaxies that are forming a giant elliptical galaxy. It appears that globular star clusters may be being created by the collision explaining why many such elliptical galaxies have so many globular clusters.

The galaxy is classed as (r)SA(r)0 at NED and SB0 at the NGC project. It was discovered by William Herschel on October 26, 1785 but is in neither of the Herschel 400 observing programs.

For a good ground based image of it see:
http://cseligman.com/text/atlas/ngc7252.jpg

I can't see much resemblance to the "Atoms for Peace" stamp it got its name from but you can try here:
http://en.wikipedia.org/wiki/Atoms_for_Peace

It is a famous merger featured in the classic paper by Toomre on determining the sequence with time in galaxy mergers. You can read more on that here:
http://astronomy.swin.edu.au/cms/astro/cosmos/t/Toomre+Sequence

The Hubble Space Telescope shows that its core is a rather normal looking spiral galaxy with no hint of the other galaxy. Was it completely torn apart leaving the looping star trail and plumes?
http://www.spacetelescope.org/static/archives/images/large/opo9311a.jpg

At the bottom of my image, a bit right of center,+ is the galaxy 2dFGRS S063Z192 at 800 million light-years. It appears as 2 galaxies in my image. NED's position is the dark gap between them. Each appears nearly circular but NED shows the galaxy as 2.8 times longer than high. This fits the size and shape of both round blobs. I still think it is two galaxies but my resolution is too poor to say for sure.

Toward the end of the northwest plume is a blue object. NED calls it NGC 7252W and gives it the designation of "galaxy". Is it really one or a star cloud in the plume? The HST image doesn't include it. It does have a similar redshift to Arp 226. To the northeast is the obvious separate barred galaxy NED calls NGC 7252 COM01. It too has a similar redshift as does 2dFGRS S063Z143, a small dwarf galaxy to the east of Arp 226.

Due to the severe extinction, I get this low over the lake the image loses about 2 magnitudes over my normal images. Chromatic dispersion elongates the stars as well. It needs many hours of exposure but this low I get only an hour a night and that only when seeing is very good. This makes it impossible for me to get the time needed. After 5 months this is all I could get.

There are three asteroids in the image. Since the 4 images used for the L image were all taken different nights, only one of which contained the asteroid, I had to "adjust" the image to show them. I used the 4 frames taken the night these three were in the image only for the asteroids. I had to adjust for varying focus as well. Other asteroids were in the other three frames used for the luminance image but they only appeared in one frame so a complete 40 minute track didn't exist, they were arbitrarily cloned out of existence. Nearest Arp 226 was (259764) 2004 BY4 at magnitude 19.3. Next closest to the southwest was (248913) 2006 VQ80 at magnitude 18.5. At the very top near the middle was (39603) 1993 TU20. It is listed as also magnitude 18.5 but obviously was far fainter. The images used for these 3 asteroids was taken on August 12, 2010 centered on about 6:10 UT. None of the frames were used for Arp 226 or anything else. I should have just ignored them but I like including the trails.

Arp's image: http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp226.jpeg

14" LX200R @ f/10, L=4x10' RGB=3x10'x3, STL-11000XM, Paramount ME

Related Designations for ARP226

ARP227

This is another retry at an Arp entry I wasn't happy with the first time around. I wanted to get a lot more time but the weather had other ideas and most of the data wasn't usable due to horrid seeing and clouds. There's a lot to talk about here. It's a long read for those interested. The rest can just jump to the pictures.

Arp 227 falls into Arp's category for galaxies with concentric rings, modern astronomers refer to it as a shell galaxy. It is located in Pisces about 93 million light-years distant by redshift. Many papers say 100 million which, given the uncertainty of redshift distances is a nice round estimate I won't argue with. It consists of two galaxies, NGC 474, the shell galaxy and a true companion NGC 470 to the west. Some sources deny NGC 470 is part of Apr 227. Arp did frame his image to give 470 and 474 equal weight but didn't list it as a member. Another shell galaxy is in my image, NGC 467 to the southwest but it would seem to be unrelated being some 2.5 times further away. While not exceedingly rare, shell galaxies with such well-defined shells as these two are uncommon, to have two in the same small area of sky exceedingly rare. I don't know of another example.

NGC 474 is classed as (R')SA(s)0^0^ at NED and (R')SA(s)0 at the NGC project. Shell galaxies are thought to form a couple different ways. One is a direct radial hit by a small, low mass, galaxy that is destroyed in the process. Stars are flung out, turn around and fall back. This, in simulations, causes them to linger for a bit as they turn around creating an area of higher density. Those with further orbits before the companion was torn apart go out further to a more distant turnaround point. Thus high star density shells are formed. I don't pretend to begin to understand this concept. The other method involves a grazing impact that also destroys the companion. In this case, its stars are flung out into spiral-like loops that then loosely wrap about the host galaxy like a fishing line snarl open face fishing reels can create. At least I can understand the fishing line snarl but the rest still eludes me. See: https://apod.nasa.gov/apod/ap140105.html for more on this and a much deeper image than mine. Arp, always the contrarian, has a really weird explanation. The companion spirals in creating the rings. We do see some such rings, in fact, there's a few around our galaxy due to dwarf galaxies our galaxy has and still is in one case, dining on. But they are far from sharply defined as they are in shell galaxies. Arp though goes on to say that both 474 and 470 are the remains of a larger active galaxy and that the two quasars near 470, see my annotated version, were ejected from the center of the original disrupted system. Of course, he uses his reworked physics to explain away their redshift that puts them billions of light-years behind these two galaxies.

So how does NGC 470 fit into this? Wish I knew. It is classed as SA(rs)b by both NED and the NGC project. Its arms are unusually thick and uneven. That could be perfectly natural for it. Or could this be due to interaction with NGC 474? NGC 470 does have some small possible plumes coming off either end that might indicate interaction with NGC 474 but I doubt its gravity is sufficient to create the shells in the much larger galaxy yet be so little influenced itself. Most papers on 474 say there's no other evidence of a collision with another galaxy but for its shell structure. No second nucleus or apparently evidence for two planes of stellar motion. Though if the idea the companion was so low density to be totally destroyed the lack of anything else but the shell structure isn't all that surprising to me, but I'm far from an expert on this! I found papers saying the two are and are not interacting. I vote with the latter (barely) but will reserve the right to change my vote if better evidence for interaction is found.

NGC 470 and 474 were discovered by William Herschel on December 13, 1784 while NGC 467 was found by him on October 8, 1785. None of these are in either of the Herschel 400 observing programs.

A third member of the group is MGC +00-04-083 to the southwest. It has about the same redshift but doesn't appear to be interacting with anything and is quite small and insignificant compared to the other two. A distant galaxy appears to overlap it to the NW of its core. This little guy, as with most in the image is anonymous.

Then there's the other shell galaxy NGC 467 at nearly a quarter billion light-years. It too has a companion, to the east-southeast this time PGC 1249151. I can't find a redshift for it. Is it a true companion or just a line of sight galaxy? Like NGC 474, besides the well-defined shells, it too has plumes. The most obvious to the south but if you look closely there's a faint arc of stars even further north than the bright plume extends south. I needed more time to bring these out in both galaxies. CGCG 385-068 at the very bottom of my image to its southeast has a similar redshift and shows a faint tidal tail. While I can't see it as causing the shells it could have had some interaction creating the plumes I suppose.

This is one very busy image that could have used a lot more time. Maybe a third try is needed.

There are 5 asteroids in the image, one seen atop the shells of NGC 474. Details are on the annotated image.

Arp's image:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp227.jpeg

14" LX200R @ f/10, L=8x10' RGB=2x10', STL-11000XM, Paramount ME

Related Designations for ARP227

ARP228

Arp 228/IC 0162 is the largest and likely anchoring galaxy of a small cluster of galaxies. USGC U076 is one designation NED uses. Their redshift distances range from 220 to 250 million light-years. The difference is mostly due to their orbital velocities about a common center of gravity. Since Arp 228 is likely the anchor its redshift of 223 million light-years may be a good estimate of the distance to the group. It is classed as S0. Arp put it in his class of concentric ring galaxies. It appears his image failed to pick up the extent of the outer ring. At least the outer ring I picked up. Deeper shots may show yet another ring for all I know. Arp 228 likely is the end result of a normal spiral fattened up on many smaller galaxies in its group.

MCG +02-05-039 just to its southeast is a very odd looking galaxy. NED doesn't try to classify it. Is it being distorted by Arp 228? Sort of reminded me of a Vargas Girl, big bust, tiny waist and large hips. Its redshift puts it at 230 million light-years which may be yet another indication it is getting whip-sawed by Arp 228. To the west of Arp 228 is another pair of galaxies. IC 0161/UGC 01266 and UGC 01266 Notes01. They show redshift distances of 230 and 250 million light-years respectively. The little guy may also be getting whip-sawed by the gravity of the larger or they may just be along the same line of sight. A note at NED says IC 161 is nonexistent but most say it does. It is true Swift's position for it and 162 were poor with 161 being right at his magnitude limit but most credit him with both galaxies The Kanipe-Webb book only uses the MCG designation but NED itself gives IC 0161 as its primary designation for the galaxy. The IC description of 161 may not fit. It says "considerably extremely faint, very small, round." Though the visual observers may only be seeing the core which is round. For comparison the description of 162 which is Arp 228 reads, extremely faint, small, little extended. That would indicate only its core was likely seen as well. Most say Lewis Swift saw IC 161 on January 8, 1891 and IC 162 on October 3, 1889. What causes some to say 161 is nonexistent or lost is that it is fainter yet was found first. Being so close together they question him seeing the fainter one but missing the brighter. But galaxy visibility depends on surface brightness. Due to IC 161 having a starlike core and a large but low surface brightness disk it could be Swift mistook it for a star. Not having tried to see either visually I can't say if this is possible or not.

UGC 01268 north of Arp 228 is classed as S? It appears to be a red spiral of some sort. Its redshift says it is 220 million light years distant, the closest of the group but again this may not necessarily be the case.

UGC 01263 is the face on spiral to the northwest of Arp 228. It too is classed as only S? It appears to be a barred spiral with a ring and outer arms. It certainly is peculiar. Redshift puts it at 227 million light years. It seems unusually red for such a spiral. The pair of red double stars between it and Arp 228 are much redder than I normally see. Are they a true pair I wonder?

The only other galaxy in the image with a redshift is MRC 0145+102. It is listed at 21.4 magnitude but no filter is given. My normal limiting magnitude is about 22 and from the estimated brightness of the asteroids in the image it would appear I'm reaching at least magnitude 22 probably 22.5 or so. But this one is far fainter than that would indicate. It is a radio source. I've noted the optical component on the annotated image, southwest of Arp 228. According to NED, it has a redshift of z=2.845000! That means the light I'm imaging was well into the ultraviolet when it left the galaxy some 11.4 billion years ago. That has to be one super object to show a physical size at that distance! You may have to enlarge the image to find it.

I managed to pick up 6 asteroids, most exceedingly faint. I found the three faintest only because the Minor Planet Center said they were there and gave the position. All are shown in the annotated image.

Arp's image:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp228.jpeg

14" LX200R @ f/10, L=4x10' RGB=2x10'x3, STL-11000XM, Paramount ME

Related Designations for ARP228

ARP229

This is my second try at the NGC 507 group. The first attempt was centered on NGC 507 as part of my project to image the Arp Galaxies. But that missed much of the group to the north. Also, the color data with the original was rather poor. This time I got good color data but seeing wasn't so hot. Since the framing is very different I couldn't use the good color data with the better seeing of the first image. The group is located in the northeast corner of Pisces, near M33. Its distance is listed at about 250 million light-years by NED though this seems at odds with the distances of its members. In fact, NGC 507 which appears to be the Big Cluster Galaxy of the group but is shown at only 210 million light-years. In fact, the redshifts of the galaxies NED considers to be group members seems rather centered about this value with only one in my image greater than 250 and most in the 200 million light-year range. Normally I'd not include the distance values in an annotated image but because of this discrepancy did so in this case. A question mark for distance means the galaxy had no redshift value but appears it may be part of the group. A couple oddball blue galaxies weren't in NED at all as galaxies. They are listed only with a question mark. While the data release 8 of the SDSS covers this field that hasn't yet been added to NED so many galaxies are omitted. These two, however, appear highly distorted and may be small members of the group that didn't fare well in interactions. One, northwest of Arp 229 is a very blue irregular mess with several bright star clouds. The other to the northeast of Arp 229 is drawn out into a streak similar to an edge on galaxy but has a dim area a bit southeast of center that shouldn't be in a true edge on galaxy. Is it two galaxies? (Edit: NED now includes these. The NE streak is GALEX J102409.16+332342.7 and the NW mess is GALEX J012320.62+332049.5. Both are identified as a UltraViolet Excess Source but have no distance information.) In the Sloan image which includes near UV light, the lower section is a lot bluer than the upper. That is just the opposite of my image. This would indicate the lower part is full of super hot blue stars emitting mostly in UV light I can't see as my filters block UV light. My corrector plate can't handle that color which would fuzz up my images so I use a filter that limits my coverage to the visible part of the spectrum.

Arp put #229 in his category for galaxies with concentric rings. Arp's comment on NGC 507 reads: "Circular or near circular rings of small density difference". My first try didn't seem to show these rings very well. Even though my seeing was worse for this image the rings show up better.

Besides picking up a lot more of the of the group I also wanted to go deeper so waited for a night of better transparency. I noticed many of the galaxies in the original had a slight hint of extended halos about them. On this better night, I was able to pull those out of the background. Indeed a surprising number of them have halos and plumes. It appears that a large number of these galaxies have had close encounters with other group members in the past. I've pushed the background to higher than normal levels and reduced the contrast a bit between the background and bright objects to better show these faint structures. I would have used more time but the skies were not cooperative.

NGC 507 is a strong radio galaxy and has an extensive X-ray emission out to about 16 arc minutes which is about the width of my image frame! The shells are likely the result of it being well fed on lesser members of the group. The X-rays due to the hot gasses ejected due to its cannibalism. It is classed SA(r)0^0^ at NED and SA(R)0°at the NGC project.

The NGC 507/WBL 038 group consists of 22 members according to NED but no size is given. It is part of the much larger ZwCl 0107.5+3212 which NED lists as containing 625 members in a diameter of 6 degrees at a distance of 220 million light-years. It is centered nearly 3 degrees to the west-southwest putting this group on its eastern edge.

NGC 508 is the other galaxy in Arp 229. It is listed as E0: by NED and E by the NGC Project. NGC 507 and 508 were discovered by William Herschel on September 12, 1784. Neither made a Herschel 400 observing program.

Other major members of the cluster include:
NGC 483 has a very large outer ring that appears totally disconnected from the rest of the galaxy. I find no mention of this ring in the literature. NED classes it as S? and the NGC Project says S. Their visual description misses the ring as well though it is likely too faint to ever see visually. Seligman says (R)S0? so is the only one to take the ring into account. It was discovered by John Herschel on November 11, 1827

IC 1680 in the lower right corner is listed by NED as S0 with no comments. It was found by Stephane Javelle on November 29, 1899

IC 1682 to the left of 1680 is not classified by NED though a note reads: "Elliptical red object." and NED calls it a "high surface brightness galaxy" The latter I see. But it doesn't appear unusually red for an elliptical galaxy though it looks more like S0 to my eye. Javelle found it the same night as IC 1680.

To the north again is LEDA 169765 and 2MFGC 1037. While a close pair optically they show no sign of interaction. So one is likely quite a bit closer. With no data on the IR strong flat galaxy, there's no way to tell which is closer or even if the flat galaxy is a true member of the group. I feel it is but it could be a small galaxy much closer or a huge one further away. Both galaxies are strong in IR light.

NGC 494 lies on the bottom edge. It is listed as Sab by both NED and the NGC project. At first glance, it appears quite normal but look closer and there's a plume on its western (right) side. In the annotated version the label covers up some of it. It was found by John Herschel on November 22, 1827.

NGC 495 to the north is classed by NED as (R')SB(s)0/a pec: and more simply as SB0/SBa by the NGC project. That latter description would be correct but for the huge faint plumes off both of its spiral arms. That apparently is what earned it the pec label. Except for those, it looks like a typical late barred spiral. Interaction with another cluster member likely explains the plumes. William Herschel found it on September 12, 1784.

NGC 496 is a Sbc spiral. It seems to have a normal two-arm structure in the center that expands suddenly to a many arm spiral. Other than that it is pretty normal looking. It was also discovered by William Herschel on September 12, 1784.

NGC 498 is listed as S0 by NED and E by the NGC Project. I see a hint of spiral structure so will side with the S0 designation. It was found by R.J. Mitchell on October 23, 1856.

NGC 499 is also IC 1686. It is listed as S0- by both the NGC Project and NED. It too seems pretty normal for a large galaxy of its type. Another William Herschel found that night of September 12, 1784. But it also got the designation IC 1686 when Javelle found it December 1, 1899 but gave a slightly different position than Herschel not realizing it was the same galaxy Herschel had found a century earlier.

IC 1684 and IC 1685 have no classification at NED. IC 1684 appears to be a rather normal disk galaxy sitting in a larger faint halo. NGC 1685 seems to have two cores, a brighter one well below center and a fainter one just above center. Above that is a star. I can't prove there are two cores, but the PSF of them in my image doesn't fit a star. One may be a background galaxy I suppose. Both were discovered by Stephane Javelle on March 30, 1899.

NGC 501 is a compact E0 per NED and just a compact galaxy per the NGC project. It was discovered by one of the Lord Rosse's assistants, R. J. Mitchell on October 28, 1856.

IC 1687 is also a compact E0 galaxy per NED though it does seem to have a bit of a halo that a compact shouldn't have. Javelle found it on December 1, 1899.

IC 1691 isn't classified at NED others say S? To my eye, it is SB0 or maybe SBa. It looks rather normal. Javelle found it on December 2, 1899.

NGC 503 is Listed by NED as E0? and E by the NGC project. It has a faint large outer halo both seem to ignore nor is anything listed on it in the literature. Such halos are rarely seen in elliptical galaxies as far as I've seen. I'm surprised nothing is being said about it. Makes me wonder if it's the remains of a galaxy that lost a lot of its stars in a past interaction though it seems normal otherwise. It was first seen by Heinrich d'Arrest on August 13, 1863.

NGC 504 is an S0 galaxy. It was discovered by William Herschel's son was discovered by his son John Herschel on November 22, 1827.

ARK 039 is the last strongly haloed galaxy in the image. In this case, it is mentioned in a note at NED which reads: "Elliptical red object with envelope." That's it! I don't see it as unusually red. It looks like a rather typical ring type barred spiral though NED classes it as S? Looks to be it should be SB at least. Though the outer halo (envelope) is very slightly red it is far bluer than the rest of the galaxy which is rather odd. ARK is the Arakelian Emission Line Objects catalog so this galaxy has rather strong H-alpha emission which would fit with it making a lot of stars but isn't a strong IR galaxy so those new stars aren't hidden behind a dense dust shield. This might explain the bluer color to the envelope area. Pure guess on my part.

One asteroid wandered into the scene, 2003 UE 21 at an estimated magnitude 19.6 according to the Minor Planet Center.

Arp's image of Arp 229 is at:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp229.jpeg

14" LX200R @ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME

Related Designations for ARP229

ARP230

Polar Ring Galaxy -- Arp 230

Arp 230/IC 51 is a small galaxy about 62 million miles from us in the western end of the constellation of Cetus the sea monster, north of Beta Ceti. Arp put it in his category of galaxies with concentric shells. His comment: "Inner and outer shells visible in direction of axis only." It is now thought to be a polar ring galaxy and the result of a merger of two galaxies sometime in the past. It is quite small even now so these weren't Milky Way size galaxies before the merger. Note in my image that there appears to be some faint debris of the merger to the south-southeast. I suspected it to be just a reflection but moving the scope didn't alter it as it would a reflection so it must be real. I forgot to move it back after the test so it is off center. The galaxy was discovered by Stephan Javelle on August 30, 1892.

The Hubble Space Telescope took a high-resolution image of the core of this galaxy. Colors don't match mine but that could be due to the filters used. I didn't go back to the original data and see what filters were used. For once the image is oriented the same as mine. I see no sign of a double core but they may have merged or are hidden behind our apparently near edge on view. Looks to me like the arms belong to one galaxy while the north-south elongation may reflect the axis of the other galaxy. I'd love to see it in 3D. NED classes it as S0 pec?. It is listed as PRC B-01 in the Polar Ring Catalog.

The field is very uninteresting with little in the way of faint background stars or galaxies. Only one other galaxy has a redshift given. Find the brightest orange star near the upper right corner and go east, left. First, you come to a star with an edge on galaxy just above and right of it. Nearby directly east is 2MASX J00454753-1320157, a rather orange elliptical looking galaxy with a redshift of 1.6 billion light years. The edge on is the anonymous galaxy APMUKS(BJ) B004314.84-133646.7. There's an interesting looking, very blue, galaxy due east of Arp 230 about 60% of the way to the edge. It is yet another anonymous galaxy APMUKS(BJ) B004436.29-134249.9 in that all we have on it is what an automatic plate measuring engine found, mostly position and magnitude. That's the way it goes with this field.

If you enlarge the field about 2x a lot of faint fuzzies start to appear but otherwise, it is a pretty dull field but for Arp 230.

Hubble image:
http://apod.nasa.gov/apod/ap960822.html

Arp's image:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp230.jpeg

14" LX200R @ f/10, L=4x10 RGB=2x10x3, STL-11000XM, Paramount ME

Related Designations for ARP230

ARP231

Arp 231 is a peculiar galaxy system in northwestern Cetus about 250 million light-years away. Arp put it in his category: Concentric Ring Galaxies. Often his categories had little to do with what was going on, rather they were just an attempt to categorize by appearance. Often a category would contain galaxies of very different natures that just happened to look the same. That isn't so much the case with his concentric ring category. These are thought to be caused by the interaction of two or more galaxies. Sharp rings as in this case coming when a small, dense gas-poor galaxy merges with a much larger one with warm dust and gas. Arp 231 appears to be such a system. For a paper showing how such galaxies are created see: http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1988ApJ...331..682H&data_type=PDF_HIGH&whole_paper=YES&type=PRINTER&filetype=.pdf

Arp 231 consists of two parts IC 1575a and IC 1575B divided by a curving dust lane with IC 1525a being the golden colored northern part and IC 1575B the bluer southern part. I suspect, can't prove, the golden IC 1525a would be the compact, dense gas and dust free galaxy and virtually everything else is debris from both plus the large galaxy it is interacting with. The galaxy was discovered by Lewis Swift on September 5, 1896.

Arp's note on the system reads: "Faintest arc extends about 2' S of the nucleus with absorption." Here he missed mentioning an even fainter arc to the west (right) running behind a blue star that extends out even further than the one Arp saw. I've placed the label for Arp 231 beside the western arc's southern end. I saw hints of even more distant ones in the original FITS but so weak they could be noise. In any case, they didn't survive color addition. This one will need more time to decide the issue as I didn't find anything deeper than mine on the net.

While everything indicates this is two interacting galaxies NED seems to disagree. It classifies parts a and b as simply Part of a single galaxy. Though it does show the north part listed as MCG-01-03-002 and the southern as MCG-01-03-003. NED Classifies the system as S0+ pec. No classification is given for either part though the northern part is stated to have the morphology of a dusty elliptical. This even though they give its size as only 12 seconds of arc (that of the golden core). I still think most of what is seen above and below the dust lane is the larger disk galaxy that the small dense elliptical ran into. I found no papers on this system other than a few that mention it in passing as similar to what the authors were studying. Too bad as it appears to be quite interesting.

I took this one over two nights. First night had excellent seeing but very poor transparency that got worse as the imaging went on. Only the luminance data was usable. The second night had good transparency but horrid seeing, three times worse than through the heavy haze of the night before. The result was good detail in the first image and the ability to see deep in the second but with no resolution. Also, I had bright asteroids pass through the image both nights. I ended up using the second night for color (resolution issues not so important) and for the faint outer parts of Arp 231. The first night's luminance was used for everything else including all the stars and other galaxies. This left me with color tracks of two bright asteroids with no luminance track to go with it. I went back and added in the asteroids from the second night to the luminance data rather than eliminate the color trails. One bright asteroid (lower middle) was from the first night. You can see the seeing difference comparing its trail to that of the two from the second night. It is much finer thanks to far better seeing. Since no color data was not usable the first night it has no color trails. Since seeing the second night was poor I took the color data first hoping by the time it got near the meridian seeing would be better for the second run of luminance data. That was not the case, however. But it does explain why the color comes before the luminance trail. The night before I'd waited until the object was closer to the meridian then took luminance on the east side and color on the west but due to the wait fall fog nailed me. I didn't take that chance the second night. Didn't much matter as seeing never did improve. It was taken October 3rd and 4th, 2010 UT.

The first-night asteroid (without color trails) is (9146) Tulikov at magnitude 16.8. It also shows in the lower right corner from the second night. That's how far it moved in 24 hours. The bright asteroid to the lower left of Arp 231 is (21986) Alexanduribe at magnitude 16.9. 4 other fainter asteroids from the second night were lost when I limited that night to showing only the shells and bright obvious asteroids I had noticed before I started searching the data. One fainter one I did notice and thus include is (110618) 2001 TC149 19.1 in the upper left corner.

The naming citation for Alexanduribe reads:
Alexander Tyler Uribe (b. 1990) is a finalist in the 2005 Discovery Channel Young Scientist Challenge (DCYSC), a middle school science competition, for his physical science project. He attends the Willow Creek Middle School, North Lehi, Utah.
Yes, the asteroid name cuts his first name two letters short for some reason.

The naming citation for Tulikov reads:
Composer Serafim Sergeevich Tulikov (b. 1914), People's artist of the U.S.S.R., is the author of many lyrical and patriotic songs that are very popular with the Russian people.

Arp's image:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp231.jpeg

14" LX200R @ f/10, L=8(4)X10' RGB=2X10'X3, STL-11000XM, Paramount ME

Related Designations for ARP231

ARP232

Arp 137/NGC 2914 is the other peculiar galaxy in the image just to the southeast (lower left) of Arp 232. It falls under Arp's category of Elliptical and Elliptical-like Galaxies: Material emanating from elliptical galaxies. It does have a plume of material coming off the south end and a small faint one off the northern end. Arp's image makes it look like there's an odd hook like arm coming off the northern side as well. I don't know which he is referring to. In my image that northern "hook" is seen as a continuous ring-like structure, or is it a one-armed spiral? Also of interest is the very high proper motion of a star near the "bright" star to the east of Arp 137. In Arp's image, it is northwest of the "bright" star while some 45 years or so later it has moved to the south-southwest of it. I've marked it as HPM in the annotated image. William Herschel found this galaxy on March 3, 1786.

Arp 232/NGC 2911 turned out more interesting than I thought it would be when I was looking at the raw data and Arp's image. Arp put it in his category: Galaxies (not classifiable as S or E); Appearance of fission. I really don't see it in either his image or mine but it sure does have some interesting dust lanes. Two linear ones that make an X near the core rather similar to NGC 660 just not as spectacular. Another forms an arc. Could it be the cause of his fission category? Arp did comment on the larger linear dust lane saying "Absorption lane reaching away from galaxy." It barely shows in his image. I don't see the other dust lanes in his image. Note that Dennis Webb's webpage puts this one in the concentric rings category. He tells me that from Arp's notes it was ambiguous which category it belonged in. He thought it looked more like concentric rings was the right category and put it there for the web page. Later researching this one for their book Dennis contacted Arp who told him it belonged in the fission category. That is what the book shows but the webpage hasn't been updated as of the time I am typing this.

Arp 232 is NGC 2911 and is part of a group of galaxies that includes 3 other NGC objects though one is subject to debate. One of the others is also an Arp galaxy as well though I didn't realize it at the time. Nor did I realize it a month later when I took it though that data is not as good so I'm going with this image. It was discovered by William Herschel on March 11, 1784. Like the other one in this image, he found it isn't in either of the Herschel 400 observing programs.

Arp 232 is classed as SA(s)0:pec;Sy LINER by NED and the NGC Project. NED puts it about 155 million light years distant by its red shift. All that dust is very unusual for an S0 galaxy as is the very distorted shape of its outer envelope. While I found nothing on it, it does appear to me it interacted with or ate a companion. Something had to trigger the Seyfert and LINER activity of its nucleus. I didn't see anything indicating it was interacting with Arp 137 but certainly that galaxy has had a run in with some other galaxy to create its southern plume and odd arm structure. Arp 137 is classed as SB(s)ab by NED and and the NGC project. So none of them see the arm as a ring like I was thinking. It's nearly identical red shift puts it at 160 million light years making the separation between the two at about 225 thousand light years if they were at the same distance from us. Close enough I'd suspect some interaction.

To add to the oddities in this image there's a star-like object just off the NE arm of Arp 137. NED identifies it as SDSS J093403.79+100646.8 saying it is part of Arp 137. It isn't a star, that is certain. Its point spread function (how its light is distributed) shows it to have an angular size and not just a point source like a star. But is it truly part of Arp 137? I don't think so. The galaxy shows no hint of star clusters at my resolution. For there to be a single one making this bright blob and for it to be just off the side of the "ring" doesn't seem reasonable. Adding to the confusion NED, while saying it is part of Arp 137 with a redshift of 160 million light years gives this object a redshift that puts it 1.8 billion light years distant. Far beyond Arp 137. NED doesn't say why it ignores this and thinks it's part of Arp 137. Though I've seen a couple cases where the SDSS redshift was apparently very wrong I doubt this is one of them. I don't have a final answer, however.

The tiny blue galaxy NE of Arp 232 is another problem. Some sources say it is NGC 2912. Other sources say NGC 2912 is a duplicate entry for NGC 2914 (Arp 137) The NGC project, however, says NGC 2912 is just a star. I like Dr. Corwin's logic and will go with him and NED saying NGC 2912 is a star. Seligman agrees with Dr. Corwin on this. The star was first recorded by Herman Schultz on April 3, 1870. The PGC records it as PGC 3325919. That leaves this blue galaxy. NED and Seligman say it is PGC 027167. They put it at a redshift distance of 172 million light-years making it a dwarf member of the group. They class it as Im, an irregular dwarf of the Magellanic type. To me, it looks like a very small spiral but that likely is due to my limited resolution.

There are many more minor members of the group as well as one large member, NGC 2919 in the upper left of my image. It shows a lot of interesting detail. NED classes it as SAB(r)b: with a redshift that puts it only 127 million light-years away. Is it truly a member of the group with a somewhat unusual red sift due to its motions in the cluster or just a foreground object. I flipped a mental coin and it came up with it being a member of the group. It was discovered by William Tempel on February 1, 1877. The annotated image lists galaxies that have a redshift indicating they are members of the group listed by catalog name and distance. Galaxies and quasars not members of the group with redshift data are listed by their redshift distance. All distances are in billions of light years and determined using NED's 5 year WMAP option.

Arp 232/NGC 2911 was discovered by William Herschel on March 11, 1784. NGC 2912, just a star, was cataloged by Herman Schultz on April 3, 1870. Arp 137/NGC 2914 was discovered by William Herschel on March 3, 1786. Neither of Herschel's discoveries are in either of the Herschel observing programs. NGC 2919 was discovered by Wilhelm Tempel on February 1, 1877.

If all this isn't enough there are two asteroids in the image also identified on the annotated image. Both are near the top of the image. (51757) 2001 LA4 at magnitude 19.4 is directly above Arp 232 while (78275) 2002 PU30 at magnitude 19.8 is about 3 and a half minutes northeast of it coming out of the right side of a rather bright star.

I've included an SDSS image of this Arp pair. For some reason, it doesn't show the dust lanes of Arp 232 nearly as well as my image yet has higher resolution.

Arp's image of Arp 137 is at:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp137.jpeg

Arp's image of Arp 232 is at:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp232.jpeg

14" LX200R @ f/10, L=4x10' RGB=2x10'x3, STL-11000XM, Paramount ME

Related Designations for ARP232

ARP233

Arp 233/UGC 5720/HARO 02 is a blue compact galaxy in Ursa Major about 75 million light-years distant. It is a starburst galaxy. NED classifies it as Im Pec with HII emission lines. Arp put it in his category Galaxies (not classifiable as S or E): Appearance of Fission, one of his largest categories. He made the comment: "Narrow faint absorption lane in south-following direction." This is likely the reddish band best seen on my enlarged cropped image on the southeast end of the brightest part of the galaxy. The HARO catalog lists blue galaxies with emission lines. It is also MRK 0033 which lists ultraviolet excess sources and SBS 1029+546, a catalog of emission line source. None of this was known when Arp made his atlas.

In my image, the galaxy appears rather noisy due to a grainy appearance. This is likely real as the rest of the image shows no such "noise". Though the SDSS image doesn't seem to show this nor does it show the thin red band that is in my image.

While Arp's image seems to have a hint of a narrow "waist" to the galaxy that may be the reason for his "appearance of fission" classification it really doesn't show in my image. Though I have a blue region to the NE and more white brighter region southeast of it. That could be what is making the two lobe hint to Arp's image. "Appearance of mitosis" seems a more reasonable description to me.

So what caused this starburst activity? It's usually associated with a close encounter with another galaxy. I meant to try and include UGC 5676 in this image. Somehow I made a couple math errors and missed it by a wide margin. This galaxy is highly distorted. I need to go back and image it. Its redshift is virtually the same as Arp 233 making it a likely candidate. It isn't a starburst galaxy but is very blue indicating it has a lot of very young super hot stars which could be caused by an interaction with another galaxy. Certainly, some encounter is responsible for its distortions. While I missed imaging it I've included the SDSS image of it anyway.

But there's yet another candidate. Being about 80 minutes away it may seem too far but these are close galaxies. The distance between the two not much greater than that between M81 and M82 for instance and M81 is usually considered the reason for M82's starburst activity. The galaxy I'm referring to is Arp 217/NGC 3310. I imaged it early in my digital career and severely damaged the color data by stupidity not saving the original so I can't go back and fix it. It is on my re-shoot list, however. I prefer UGC 5676 but needed to mention this one as well.

Arp's image
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp233.jpeg

14" LX200R @ f/10, L=4x10' RGB=2x10'x3, STL-11000XM, Paramount ME

Related Designations for ARP233

ARP234

ARP 234, NGC 3738 is a large irregular galaxy that's a member of the Canes Venatici 1 Cloud though is located in Ursa Major at the bottom of the bowl of the big dipper. Arp classed it in his galaxies with appearance of fission category. As with most in this category, I have no idea what he is seeing. I just see a very blue irregular galaxy with no defined core but a large number of star-forming regions toward the center. I screwed up when taking this image. I knew that NGC 3756 would be in the same field if I put Arp 234 a bit high in the field. But I forgot which side of the meridian I was on. With it west of the meridian the camera is upside down so I should have put it low in the field, not high. The two are completely unrelated but it would have made a more interesting image with a second rather large galaxy in the image. I found many different distance estimates for Arp 235. Most fell in the 11.5 to 15 million light-year range. That would put it just beyond the local group. It was discovered by William Herschel on April 14, 1789. Like so many Arp galaxies he discovered this one too isn't in either of the observing programs for Herschel objects.

The only other galaxy in the image to show much detail is CGCG 268-054 to the NW of Arp 234. It is a 15th magnitude face on spiral at about 390 million light-years away. I sure wish it was closer as it shows some arm structure that looks really interesting. The tiny nearly star-like deep orange galaxy just to its southwest is SDSS J113459.03+543907.5, a 20th magnitude galaxy some 3.8 billion light-years distant. To its northwest making a flat isosceles triangle is a somewhat blue star-like object. It is the quasar SDSS J113455.00+543925.7 at 9.3 billion light-years. Continuing NW about the same distance you come to SDSS J113450.67+543953.0 at 1.8 billion light-years. Seems most objects in this field are rather distant except for Arp 234.

The 17th magnitude barred spiral galaxy west and a bit north of Arp 234, well south of a rather bright star is 2MASX J11344865+5433429 at 1.5 billion light-years.

North and a bit west of Arp 234, between two bright stars, is the red spindle of 2MASX J11344865+5433429, an 18th magnitude galaxy about 1.7 billion light-years distant. The spindle points southeast, just past a blue star to a blue galaxy, SDSS J113549.21+543950.4 at just under 1 billion light-years. Continuing southeast quite a ways brings you to another red spindle SDSS J113621.51+543725.3 also 1.7 billion light-years away. Going Northeast from this red spindle brings you to a rather large and bright blue possible edge on galaxy, SDSS J113644.19+543859.6, at 260 million light-years. A pretty close galaxy for this field! Follow the galaxy's plane to the northeast. You will come to a 19th magnitude blue quasar, SDSS J113722.84+544155.2 about 60% of the way to the upper left corner. It is 11.3 billion light-years distant.

There's an even more distant quasar in the image. Go directly east from Arp 234 almost to the eastern (left) edge. There's a bright blue star there. Just to its east are three "stars" in a flat triangle. The brightest is a bit north of the bright star and is really the galaxy SDSS J113737.23+543211.5. Below it and a bit west is the second brightest of the three. It is the quasar, shining at magnitude 22.0 in green light SDSS J113736.87+543149.5 at 12.2 billion light-years. The fainter, third member to the west and a bit south is the 22.2 magnitude galaxy SDSS J113735.03+543146.9. Makes you wonder if any of the stars in the image really are stars! NED has no redshift data on these two galaxies.

Directly east of Arp 234 a short ways, under a rather bright blue star is the somewhat blue 17th magnitude galaxy, 2MASXi J1136165+543150 at 260 million light-years. Further east and a bit south brings you to another blue spindle, SDSS J113645.38+543034.4 at 270 million light-years. Going north from 2MASXi J1136165+543150 brings you to a bright 17th magnitude blue-white galaxy, 2MASX J11361710+5433537 at about 770 million light-years. Northeast of it is the very red star-like galaxy SDSS J113625.97+543418.8 at 3.6 billion light-years.

Just east of due north of Arp 234, near the top of the image, is the rather bright 17th magnitude disk galaxy, 2MASX J11360396+5442187 which is 1.3 billion light-years distant. NE of it is a tight triangle of 3 objects. The brightest is MAPS-NGP O_130_0297875, below and to its left is the galaxy SDSS J113615.91+544259.4. The third object is really a tight unequal double star if you enlarge the image enough you will see this though at first glance it appears to be a galaxy and had me fooled for a bit. I have no distance estimate for either galaxy. As that's the case with the rest of the hundreds of galaxies in this image I'll stop the tour here.

The annotated image I've attached will help you find the galaxies and quasars mentioned. They are listed by distance in billions of light years. There are some really tiny nearby galaxies that appear smaller than some several billion light-years away. The close ones are really small dwarf galaxies compared to the distant ones.

Imaged April 29, 2009.

SDSS image:
http://astronomerica.awardspace.com/SDSS-27/NGC3738.php

Arp's image:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp234.jpeg

14" LX200R @ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME

Related Designations for ARP234

ARP235

ARP 235/NGC 14 is an irregular peculiar galaxy in Pegasus. Arp classified it under: "Galaxies (not classifiable as S or E); Appearance of fission. He also noted; "Faint outer oval and resolution into stars". Was he referring to all the star clusters in the core of this galaxy? I see nothing else in his photo with the 200" scope that would fit. http://nedwww.ipac.caltech.edu/level5/Arp/Figures/big_arp235.jpeg. Film grain is very obvious in the image but I see no sign of stars. This galaxy is nearby at only about 24 million light years. Therefore some earth based scopes should be able to resolve stars in it using today's detectors. In fact, the star clusters look almost like stars in the Sloan Deep Sky Survey but they are far too bright to be individual stars. It was discovered by William Herschel on September 18, 1786. It's not in either Herschel 400 observing programs.

Toward the lower left corner is a small blue galaxy with an even bluer blob within the halo just right of its core. It too is about 25 million light-years away per its redshift. It is KUG 0007+154. The small blue blob carries the designation of SDSS J000952.87+154406.9 and is listed as a separate galaxy. Both have about the same redshift. Makes me think it is more likely a star-forming region in HUG 0007+154. To be this small at this distance KUG 0007+154 would have to be a very small dwarf galaxy with the possible companion being a subdwarf.

The galaxy above ARP 235 is SDSS J000846.00+155142.2 at 530 million light years. It is very blue and seems to have an off-center core. Yet I see nothing around it that could have caused this.

To the west (right) of Arp 235, a short distance (in my image), is a small red galaxy. This is SDSS J000834.99+155011.8 at 2.07 billion light-years. It has been severely reddened by all the intergalactic dust and gas its light passed through to get to us.

At about 10 o'clock from Arp 235 is a very blue "star" at about the same distance from Arp 235 as the above galaxy. Two stars to its lower left point about at it, the lower of the two is somewhat orange in color. This is the quasar SDSS J000856.79+155045.7 at 9.0 billion light years, the most distant object in the image of which I'm aware.

To the lower left above KUG 0007+154 is the trail of asteroid (93258) 2000 SX165. At a distance of about 18 light minutes, it is the closest object to us in the image. That means the quasar is about 600 trillion times further away than the asteroid! Now that's a large depth of field!

Arp's image: http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp235.jpeg

14" LX200R @ f/10, L=4x10' RGB=2x10'x3, STL-11000XM, Paramount ME

Related Designations for ARP235