ARP043

Arp 43, IC 607 is a spiral galaxy in Arp's class: Spiral Galaxies with Low Surface Brightness Companions on Arms. The "companion" is 2MASX J10241018+1643557/ASK 647046.0, the blue blob on the southeast edge of the galaxy. Apr 43 is about 230 million light-years distant in the constellation of Leo just a degree southwest of Arp 263, the much closer, highly irregular loon-like galaxy. It was discovered on March 29, 1889 by Lewis Swift.

Unfortunately, with no redshift data on the "companion", I've put it in quotes since there's no way to tell if it really is a companion. Possibly just a line of sight alignment. Arp's comment reads: "One side of ring obscured or disrupted; other side has low surface brightness companion." This means that if there is distortion to Arp 43 it is on the wrong side! Everything is normal on the side with the "companion". Could be the "companion" passed the other side hundreds of millions of years ago and now, while seen near the other side it now too far away to cause further distortion. But then why isn't it distorted? It would be nice to have more information on this pair. I found very little though with all the snow I've been dealing with lately I haven't had much time to look. A similar blue blob of a galaxy is seen 3 minutes northeast of Arp 43, is it related? There is a hint of a possible tidal tail from Arp 43 going down to the south-southeast to a very red galaxy, 2MASX J10241324+1642567/ASK 647046.0. Again, no redshift data. This is more likely noise as the image is noisier than many due to winter airglow and ice in the atmosphere which greatly increases my sky noise.

Edit: Since this was written the SDSS has had additional data releases which show redshift for many galaxies in this image (see the annotated image). This shows it is not a true companion as its redshift puts it nearly 7 times the distance of IC 607.

While NED shows some 2280 galaxies within this image only Arp 43 has any redshift data. (see edit above as this has changed) I don't know why so I can't prepare my normal distance annotated image. However, there are 8 asteroids in the image, all but one very faint. Since many are hard to spot I've prepared an annotated asteroid image for them. Looking at the image you will see it happened yet again. An unknown asteroid seems to have slipped into the image. Being that it was taken last February it is a bit late to try and pick it up again so it will have to remain unknown until one of the automated asteroid hunting scopes picks it up again. I've listed the estimated magnitudes of known asteroids by the Minor Planet Center. These are rough estimates it would seem. Some rated brighter than others appear fainter in my image. Some asteroids are very red. My camera is not very red sensitive. This could partly explain the differences but doubt it explains all of it as such asteroids aren't all that common.

Edit: Actually the asteroid had been discovered when I took this image. Why I was unable to identify it at the time I don't know. It is (388920) 2008 SW129 at an estimated magnitude of 20.4. I've updated the annotated image.

As I couldn't find a link-able Sloan image of this one I've posted one. It shows no hint of a connection to the red galaxy so think it most likely doesn't exist.

Arp's image
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp43.jpeg

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

Related Designations for ARP043

ARP045

Arp 45 is two or three or four galaxies 400 million light-years distant in the northwest corner of Bootes. Arp put it in his category for spirals with low surface brightness companions on arms. Arp's comment: "One arm leads towards large companion, other towards small companion." Is this coincidence or is there some connection. There's another problem. Is the companion that is on the arm a galaxy as Arp indicates or just a blue knot in the arm? I don't know. UGC and Sloan, for instance, don't list it. Others such as the Vorontsov-Velyaminov Interacting Galaxies catalog as well as the CGCG and MCG list it separately. I find no redshift measurement for it. In the UGC catalog, Arp 45 is 09178. It is a triple galaxy in that catalog but the third member is not the blue knot on the arm. It is somewhat to the northwest, a normal looking disk galaxy, a bit smaller the primary galaxy of Arp 45. While an obvious spiral NED shows no classification for it. The main spiral of Arp 45 is classed S(B?)c. I thought it a rather obvious barred spiral so I don't understand the question mark. The companion, VV2b, is close to being a one-armed spiral though NED doesn't attempt to classify it. The blue object on the other arm of VV2a has neither a magnitude nor classification at NED.

Another confusing object in the image is the orange star at the upper right. At 6th magnitude, it blasted across my image causing one heck of a huge halo with my old generation 1 filters which are very prone to such halos. Taming the halo rather distorted the appearance of the star. But what has me confused is that the star is classed A2. That is normally a rather blue-white star. I checked several catalogs all say A2. I know my filters scatter far more blue light than red but never have they changed a star's color that much. The rest in the image are reasonable in color. It is quite red on the Sloan image as well, not shown in my attached images. Though the DSS plates show it brighter in blue than red. I know spectral color changes with whether the star is on the main sequence or off it in some other category but can they change this much? Why is it blue in the DSS but red in Sloan and orange for me? I can understand the IR of the Sloan image making an orange star appear red but how does it happen to a blue-white star? Anyone know what is causing this?

Several quasars are in the image, one at 3 billion light-years is closer than some galaxies in the image. Two however are at more respectable distances being over 9 billion light-years away.

In the upper left of the enlarged cropped image is an odd blue object or objects. NED lists only a 21st magnitude star in that position. In my and the SDSS image, it appears the star is one of three blobs that makes up this object. It is the one to the upper left of the other two. They appear to be galaxies but neither are listed in the SDSS according to NED. My image doesn't go as deep as normal so the SDSS lists many galaxies fainter than I am picking up yet misses these.

Arp's image
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp45.jpeg

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

Related Designations for ARP045

ARP046

Arp 46 falls under Arp's category "Spiral Galaxies: Small, high surface brightness companions on arms. The big spiral, UGC 12667, is not Arp 46. Arp 46 is the much smaller, distorted spiral down to the right (southwest) of the bigger spiral. Arp 46 consists of UGC 12665, the distorted spiral and its small companion VV 314b. Arp's comment: "Companion connected to main spiral." I'm not all that convinced that is correct. There is a nice tidal arm coming from VV 314b and overlapping UGC 12665. But I see no way to tell if they are connected. Most likely they aren't. But that tidal plum is nice in the 2x enlargement.

The pair is in northern Pegasus. They are about 230 million light- years distant based on redshift and about 210 based on corrected Tully-Fisher estimates. This is quite good agreement as these things go. UGC 12665 is classed as SB(rs)d pec. Considering its northern arm is so distorted to be unrecognizable I'd have to say the peculiar designation is well earned. I find no classification of the companion. I'd say S0 pec as drawing such a tidal arm is easier from most S0 galaxies than elliptical galaxies.

This field is out of the Sloan survey area so there's not a lot of data on the other galaxies in the field except for UGC 12667. The spiral is Scd or Scd?. Redshift puts it at about 160 million light years so it isn't related to Arp 46 at all.

The apparent distorted edge on spiral about 10 minutes to the northwest (upper right) of Arp 46 is 2MASX J23330718+3010153. I find little on it. The apparent edge on spiral (normal) directly north of the face on spiral UGC 12667, near the top edge, is 2MASX J23334841+3012482. These two are the only other galaxies in the field that I could find any catalog entry for in NED.

Arp's image:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp46.jpeg

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

Related Designations for ARP046

ARP047

Another Arp pairing

Arp 328/Hickson 72/UGC 09532. This is a chain of galaxies located in Bootes. All but one of the galaxies are about 600 million light-years distant, the other nearly twice as distant and thus not a member. Before going further and looking only at the full or cropped image, see if you can determine which is the odd galaxy out. It may not be the one you think. Arp put this group his class for galaxy chains and had this comment: "6 galaxies more or less in line; center one has semi-stellar companion." There are 7 in the chain including the sneaky interloper. Hickson also includes only 6 but one he includes is the "fraud". NED shows 7 galaxies for Arp 328 while Arp himself limits it to 6 as does Hickson. Both leave out the most southern. Yet one note at NED reads: "With respect to the original Hickson list we have included the amorphous object g which clearly interacts with galaxy c. This is the one I've marked as VV164g. G is blue and does seem to have a bulge toward c but I'm not sure this is sufficient for it to be clearly interacting. This brings us to the "semi-stellar companion" I assume he is speaking of D. While in my image it may appear to have two cores of about the same brightness the SDSS image clearly shows the southern one to be a star. There is a slight brightening north of the core but it isn't semi-stellar. Nor can I see much of anything in the burned-out core of Arp's image as it is on the website. But E does show what appears to be a distant galaxy through its disk on the east side. Could this be what Arp refers to? It does show in his image. If the possible 7th galaxy is included then E would be in the center. I've found nothing to decide this issue.

Below and left of component g is yet another compact golden elliptical like galaxy, SDSS J144759.73+190202.0 at 18th magnitude. No one considers it part of the group. Nor is any redshift data available for it. There are several small galaxies about component A as well. Are they satellites of A or distant line of sight galaxies? Probably the latter though a note at NED considers this possible.

A is classed as S0, B as S0?, C as E2, D as SB0, E as Scd, F as S0 and G as S0?.
___________________________

Arp 47/MCG +03-38-014 is classed by Arp under Spirals with low surface brightness companions on arms. I suppose that refers to the little galaxy off the north arm that curves back sharply. That galaxy is 20th magnitude SDSS J144715.24+185134.8. No redshift is given so it's unknown if it is truly a companion. There is the very obvious galaxy to the west of MCG +03-38-014. It is 16.6 magnitude NPM1G +19.0402. NED and other catalogs consider these two a pair. In fact, NED lists these to under Arp 47. Seems way too bright to be the companion on the arm Arp refers to. So which is it? I still think it the one that definitely appears to be on the arm and certainly is faint. Unfortunately, NPM1G +19.0402 doesn't have a redshift value either which doesn't help us any. NED makes no attempt to classify this obvious spiral or either "companion".

Arp's image is one of his poorest. This isn't Arp's normal work. Makes me wonder if some night assistant took this data rather than Arp himself. He may have had quirky ideas bordering on crackpot in later years but his telescope work was very precise. One possibility is Arp did, like I did, and took both of these with one image. This would have pushed the Winn Corrector to its limits and maybe beyond. Arp 48 may have been right at the edge of the image where the Winn Corrector couldn't quite handle the prime focus distortions. The stars radiate away from the position of Arp 328 like it was centered and this one just too far away for full correction. The elongation of the star in the lower right corner seems greater which fits this idea. I can't see Arp guiding this poorly.

There's no redshift data on anything in the field other than these two objects. NED lists several thousand galaxies in my field but except for these two Arp's, there's nothing on it. Note however that both are at the same approximate redshift distance and thus quite likely part of the same group.

Arp's image of 328
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp328.jpeg

Arp's image of 47
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp47.jpeg

14" LX200R @ f/10, L=8x10' RGB=2x10'x3, STL-11000XM, Paramount ME

Related Designations for ARP047

ARP048

An Arp 3 fer in Pisces!

Arp 88 (Very small pair, in cropped image above center to the right)
This one falls in his category Spirals with large, high surface brightness companions on their arms. There is very little on this one. It is also known as PGC 004728/VV 445 and listed as a galaxy pair in the VV catalog as well as the Arp Atlas. The larger spiral carries the designation 2MASX J01190524+1228240 so is an IR source. NED gives no distance data nor attempts to even classify it as a spiral. Even its magnitude estimate is blank! I'm literally drawing a blank on this one. Even the note at NED is very strange. There's only the one. I guess when as a researcher you draw a blank this is what you write:
"One of the rare cases where the companion at the end of a spiral arm is also a spiral. Here, a chain of H II regions encircles the massive condensation thus forming a small spiral ripening at the periphery of the larger one and liable to gemmate." I really doubt it is reproducing by budding as his comment would seem to indicate! The note does date to 1977. Likely he is being descriptive in a more poetic way than Arp. http://adsabs.harvard.edu/cgi-bin/bib_query?1977A%26AS...28....1V
It's a 41 meg download, I didn't download it just trusted NED's note.


Arp 119 (The obvious pair)
Arp put it in his category of Elliptical and elliptical-like galaxies close to and perturbing spirals. The southern galaxy, MCG +02-04-021, is the more interesting. It shows two radial velocities with an emission knot between the core and northern galaxy showing a radial velocity about 800 km per second faster. NED classes it as SBc with an AGN while in another place it says Sdm: LINER. A note says SA(r)cd pec. I don't really see the ring many papers mention but otherwise, I agree with this last classification.

The northern galaxy is MCG +02-04-022. It is classed as E? This seems odd to me as well. A note at NED says: "Our images show a clear stretching of this galaxy along the direction towards Arp 119S. We observe two definite components: an inner region (a < 16") where the surface brightness profile seems of de Vaucouleurs type, and other external region (a > 18") where the {mu} profile looks like a exponential profile. However, the geometric profiles do not show evidence for disky structure. At this point, the galaxy could be classified as E3 ... The total ... color is representative of E, S0 types." That I can agree with. Its radial velocity is about half waybetween the two measurements for the southern galaxy. It does appear they are interacting.

Arp's comment on this pair reads "Some material seems attracted, some repelled." Using the northern galaxies radial velocity the distance to this pair is about 640 million light-years.

The Odd looking blue galaxy below Arp 119 is MRK 0983. It is classed simply as Peculiar though appears to be a distorted spiral. I wouldn't be surprised if it isn't actually two interacting galaxies but I have nothing to support this but what I see in my image. Its radial velocity puts it at about 630 million light-years. This likely means it is part of the Arp 119 system and may have tangled with one or both Arp 119 members.

Arp 48 (lower left corner if full image -- inset in cropped image)
The third Arp entry is Arp 48 to the southeast of Arp 119. Arp put it in his category: "Spiral Galaxies with low surface brightness companions on arms." I put it in the lower right corner of the enlarged and cropped image as there wasn't much in that corner but it is a bit confusing to put it there. When I imaged Arp 119 I knew Arp 88 was coming along for the ride but missed Arp 48. In fact, I imaged it separately a couple months later never realizing I already had it. Good thing as the intentional image had poor seeing compared to the Arp 119 image. It wasn't until I went to process this image I noted Arp 48 but thought it one Arp missed until I looked it up. The pair is also known as CGCG 436-026.

Individually the lower galaxy carries the IR source designation of 2MASX J01195923+1220377 and shows a radial velocity and shows a radial velocity distance of 635 million light-years. So it too is likely part of the same group as Arp 119. NED has no notes on it nor does it attempt to classify it. It does say this: "Low surface brightness companion on end of arm. M51 Type." Now, which of three objects is this referring to, the golden galaxy, the odd blue knot or galaxy by the cut-short arm or the galaxy to the south? I see no hint of an M51 type arm structure reaching over any of these. I could sort of make this work for the smaller blue fuzz patch, though that seems more likely a part of the northern galaxy's mostly missing arm.

The northern galaxy with one good and one not so good arm is another IR source listed as 2MASX J01200039+1220537 and also as PGC 4789. NED has absolutely nothing on it. Not even a magnitude. Odd, as it appears to be the major galaxy here. Arp certainly considered it the main one. It also appears that he considered the fainter blue fuzz patch as the companion on the arm and ignored the southern galaxy entirely. His comment reads: "Some material seems attached, some repelled." This "repelling" comment may be due to the sudden cut off of the arm. Without a redshift, it is impossible to say with certainty the northern galaxy is even related to either of the other two. I'd like some confirmation here. Neither the blue knot that's Arp's "companion" nor the golden galaxy just east of the northern spiral are in NED at all. This is a very poorly researched area it would appear.

There's an obvious galaxy cluster below Arp 48. This is NSCS J01195 at 4 billion light-years. NED shows it as containing 64 members. It extends south out of this field of view. While I got all of it in the later image of Arp 48 the seeing is so bad it isn't worth processing. This view will have to do.

The only other object in my image with a redshift measurement is CGCG 436-027. It is the blue spiral nearest the upper left corner. Oddly, NED makes no attempt to classify it, not even The only other object in my image with a red shift measurement is CGCG 436-027. It is the blue spiral nearest the upper left corner. Oddly, NED makes no attempt to classify it, not even a a spiral. It too appears to be about 635 million light-years away and thus part of the same system that Arp 119 and Arp 48 reside in. Though it appears very ordinary with nicely defined spiral arms. It too is listed as an IR source (2MASX J01200039+1238007). To its lower right is another rather obvious spiral that does appear to have a southern arm drawn well away from its "body". The gap seems oddly dark in fact. It is another IR source, 2MASX J01195236+1235486. I presume it too is part of the same system but can't confirm it without more data. It too may have some distortion.The only other object in my image with a red shift measurement is CGCG 436-027. It is the blue spiral nearest the upper left corner. Oddly, NED makes no attempt to classify it, not even a a spiral. It too appears to be about 635 million light-years away and thus part of the same system that Arp 119 and Arp 48 reside in. Though it appears very ordinary with nicely defined spiral arms. It too is listed as an IR source (2MASX J01200039+1238007). To its lower right is another rather obvious spiral that does appear to have a southern arm drawn well away from its "body". The gap seems oddly dark in fact. It is another IR source, 2MASX J01195236+1235486. I presume it too is part of the same system but can't confirm it without more data. It too may have some distortion.The only other object in my image with a red shift measurement is CGCG 436-027. It is the blue spiral nearest the upper left corner. Oddly, NED makes no attempt to classify it, not even a a spiral. It too appears to be about 635 million light-years away and thus part of the same system that Arp 119 and Arp 48 reside in. Though it appears very ordinary with nicely defined spiral arms. It too is listed as an IR source (2MASX J01200039+1238007). To its lower right is another rather obvious spiral that does appear to have a southern arm drawn well away from its "body". The gap seems oddly dark in fact. It is another IR source, 2MASX J01195236+1235486. I presume it too is part of the same system but can't confirm it without more data. It too may have some distortion.The only other object in my image with a redshift measurement is CGCG 436-027. It is the blue spiral nearest the upper left corner. Oddly, NED makes no attempt to classify it, not even a a spiral. It too appears to be about 635 million light-years away and thus part of the same system that Arp 119 and Arp 48 reside in. Though it appears very ordinary with nicely defined spiral arms. It too is listed as an IR source (2MASX J01200039+1238007). To its lower right is another rather obvious spiral that does appear to have a southern arm drawn well away from its "body". The gap seems oddly dark in fact. It is another IR source, 2MASX J01195236+1235486. I presume it too is part of the same system but can't confirm it without more data. It too may have some distortion.a spiral. It too appears to be about 635 million light-years away and thus part of the same system that Arp 119 and Arp 48 reside in. Though it appears very ordinary with nicely defined spiral arms. It too is listed as an IR source (2MASX J01200039+1238007). To its lower right is another rather obvious spiral that does appear to have a southern arm drawn well away from its "body". The gap seems oddly dark in fact. It is another IR source, 2MASX J01195236+1235486. I presume it too is part of the same system but can't confirm it without more data. It too may have some distortion.

The obvious asteroid in the image is (243847) 2000 VA62 at an estimated magnitude of 17.7. This magnitude seems reasonable.

A second asteroid in the image is more difficult to find. It is near the right edge a bit below center just above a typical white star. It shows as a horizontal line about 7 pixels long so is very short. It is the slow moving asteroid (146703) 2001 VY112 at an estimated magnitude of 19.5. It appears only slightly fainter than the far brighter (243847) 2000 VA62 because its very slow motion greatly increases its exposure time on any one pixel. As there isn't much information on this field the annotated image only points out the three Arp systems and the two asteroids.

Arp's image of #48
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp48.jpeg

Arp's image of #88
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp88.jpeg

Arp's image of #119
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp119.jpeg

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

Related Designations for ARP048

ARP049

Arp 49/NGC 5665 is in Bootes. Its distance is a bit difficult to pin down. Redshift puts it about 113 million light-years distant but a recent Tully-Fisher measurement says only about 65 million light-years. A 40 year old Tully measurement agrees to its redshift. For now, I'll go with the redshift distance as being more likely closer to reality. It was discovered by William Herschel on January 30, 1784 but isn't in either Herschel 400 observing program.

Arp put it in his class of spirals with small, high surface brightness companions on the arms. His comment reads: "Appearance of wake from stellar object in eastern arm." This stellar object is NGC 5665A. Older sources consider it a separate galaxy, newer say it is part of the galaxy, not a separate one. One paper suggests this galaxy is the result of a merger that happened about a half billion years ago. Another concludes the arms couldn't be tidal in nature and its distortions are natural to the galaxy, not due to outside influences. The field is rather barren of any candidates that could have distorted it so that part is likely correct. But whether this is a merger or just a naturally weird galaxy seems still up for debate. There is one more galaxy at the same distance as Arp 49 in the image, LEDA 4421246 to the north. It's a dwarf and likely too small to bother Arp 49 in any way though it is possible it donated many of its stars to Arp 49 long ago.

My color data was severely hurt by varying clouds and haze so is a bit suspect. Still, it seems to agree fairly well to the Sloan image so I'll go with what I have for now.

Arp's image:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp49.jpeg

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

Related Designations for ARP049

ARP050

Arp 50/NGC 1520 is located in eastern Cetus just across the border with Aquarius and is just under 400 million light-years away. It is a rather questionable object in many ways. First, many catalogs, including the database in The Sky 6 that I use to point my scope say Arp 50 is NGC 5625 pointing me to the opposite side of the sky. Thus, when I set up the script file for it then went to bed I got up to find blank images and an error message telling me the object was beyond my scope's horizon limits. By default, the scope parked itself and shut down. So the camera took way out of focus images of the observatory wall two feet away from the front of the scope!

Arp 50 is really IC 1520 so when I entered that I got a good image. Not easy as it is about at my -15 degree declination limit.

Another reason this is a questionable object is Arp's classification of it under spiral galaxies with small high surface brightness companions on the arms. To what is he referring? He doesn't say. The galaxy has several bright knots and arcs in the arms as well as a faint diffuse blob on the end of the southern arm. This NED classifies as a second galaxy. It certainly doesn't have a high surface brightness, however, being nearly indistinguishable from the arm in Arp's image. There's a nice bright knot in the other arm above a short bright arc. Is this knot what Arp refers to, it does have a rather high surface brightness. Some articles I found say there is no nearby galaxy at all. Others call it a M51 type system. I can't find any high resolution images of it on the net. In my image, a few seconds of arc above the "second galaxy" according to NED and left is a near starlike object. The PSF though is not right for a star. This could be due to it being in the fuzz of the arm or because it is a distant galaxy. Flip a coin. I need far more resolution to settle this.

I'm not the only one puzzled by this one. Science writer Courtney Seligman is too. http://cseligman.com/text/atlas/ic15.htm#ic1520 Unfortunately, his image isn't any better than Arp's. Arp's image was taken under what he calls a seeing class of 1. He defines 3 as being 1" to 1.5" with each class about twice as good (5 maximum) or bad (1 minimum). So Arp's image would be taken under 4" or so seeing. And I thought my seeing was bad! The POSS survey plate images are better than his of this entry. The galaxy was discovered by Stephane Javelle on November 4, 1891.

If that low surface brightness blob is a separate galaxy is it nearby and could it have the mass to pull out that arm? There's nothing on it that I find to help answer this. To me, this is a coin flip as to the existence of a second galaxy. If none why is the arm distorted? It is a rather lonely galaxy it would appear. NED has no distance data on any other galaxy in the entire frame. One out of frame to the north is listed at 1.5 billion light-years so not involved. 2MASX J23581154-1400522, to the northeast, is the only likely candidate I find but without any distance data, there's no way to know if this is a reasonable one. Most galaxies in the field are cataloged only by the APMUKS, an automatic plate measurement survey using the UK's Schmidt telescope. This can't provide distance data. I marked one of these and could have marked a hundred or so. As with many modern catalogs, the name gives its position, J2000 coordinates in this case.

My image did pick up 5 asteroids but again, another problem. One is unknown to the Minor Planet Center and is apparently one they haven't included as yet. It might even be undiscovered. If so it will remain that way as this image was taken 2010 September 5.28UT so a bit late for follow-up. (Edit: It is still not in the Minor Planet Center's database 6 years later.) 4 others were in their database and are marked on the annotated image. The unknown is marked with a question mark, the others with their name and the planet center's magnitude estimate. One is buried in the glow of a "bright" (7th magnitude so too faint to see naked eye) F2V type star.

Arp's image:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp50.jpeg

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

Related Designations for ARP050

ARP051

This is a redo of this pair of Arp galaxies in western Cetus about 2 degrees northeast of Arp 50. At -13 degrees declination I rarely get very good seeing for this pair. Seeing was poor in my 2008 attempt and fair for this one. Seeing it is better and my research was rather weak last time I'm redoing it. I must have entered something wrong as the galaxies aren't centered.

Arp 51 is the small spiral to the lower right of the odd pair of galaxies, Arp 144. Like Arp 50 it is in Arp's category for spirals with high surface brightness galaxies on an arm. The spiral is an IR galaxy in the 2MASS catalog also known as PGC 475 and MCG -02-01-024. Some catalogs incorrectly call it NGC 7828 which is part of Arp 144. NED has no distance data on it. The companion is ChaBG 069 (Chavira blue galaxies catalog) which NED shows as both a galaxy and as part of a galaxy. So which is it? A knot in an arm or a separate galaxy? Notes at NED on both the spiral and the object refer to it as simply an "object". Like for Arp 50, it is near a pulled out arm which is suggestive but certainly not conclusive. To me, it appears to be a background galaxy unrelated to the spiral. This is just the way it looks to me, of course. What do you see? Arp made no comment on this one.

Arp 144 is in Arp's category for material emanating from elliptical or elliptical-like galaxies. I can't understand what he means by this. Obviously, this is two interacting galaxies one an elliptical-like and one a mess. Arp 144 is about 250 million light-years distant. It is composed of at least two galaxies, NGC 7828 and NGC 7829. The latter is the elliptical-like galaxy as it is classed as S0 pec. NGC 7828 is incorrectly shown as Arp 50 in The Sky's database, maybe this accounts for my pointing error. It is classed as Im pec. So does Arp see NGC 7828 "emanating" from NGC 7829? or is it just the halo of stars around NGC 7829's core that is "emanating"? The Kanipe-Webb book is silent on this which isn't surprising. Arp left no comment to guide us either. Adding to the confusion one note says: "The spiral or a pair of galaxies are perturbed by a compact elliptical galaxy." So this source says NGC 7828 may be two galaxies. I find no other mention of this but it seems possible to me. Both galaxies were discovered by Francis Leavenworth in 1886.

Now, what about the very blue star-like object in NGC 7828? Is it a foreground star or is it a very blue knot of stars in the galaxy? The object is listed as a star in the Hubble Guide Star Catalog but the cores of NGC 7828 and 7829 are also listed as stars in the catalog. So this doesn't help any. NED doesn't show anything at this position so is of no help. The PSF in my image is galaxy like rather than a star so I will say it is part of the galaxy.

Adding to the confusion I found this: "According to a note in the IC II, NGC 7829 is a star [13 mag]." Visually 7829 does appear rather starlike and this note dates back to visual descriptions so isn't surprising.

Arp's images of these two are taken from the same 30 minute exposure on 103a-D film under seeing 3 (1" to 1.5") conditions. Much better than I had though some of the star knots in NGC 7829 seen in his image are barely visible in mine with 2.5" to 3" seeing. Good for so low in the sky.

Yes, I know it looks a bit like the Star Trek Enterprise is shooting a massive photon torpedo out its backside. A bit late as much of the starboard side of the saucer section seems to be missing.

The field is well outside the Sloan survey but a few galaxies in the image have distance data so I did prepare an annotated image for those few entries.

The entry for 6dF J0006212-131716 is labeled a galaxy but considering it is star-like and listed with a redshift of z=2.878448 which puts it over 11 billion light-years out I have to think it is really a quasar. 6dF stands for the 6 degree Field Survey. Another odd catalog is the LSCB which is the Low Central Surface Brightness catalog. LEDA = Lyon Extragalactic DAtabase for numbers above 73197. Numbers lower than this are just duplicates of the PGC catalog.

I labeled some of the brighter or more interesting looking galaxies. Only three besides Arp 144 have redshift data and one of those is mentioned above. Most are from an automatic plate measurement survey so has little information other than magnitude.

Arp's image of Arp 51:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp51.jpeg

Arp's image of Arp 144
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp144.jpeg

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

Related Designations for ARP051

ARP052

Arp 52 is one of the dud Arp galaxies, at least for my system. I needed a good night that would support 0.5" imaging. I've had more than usual of such nights but not the night I imaged it so I settled for my standard 1" pixel size. Arp 52, CGCG 421-027, doesn't have any classification that I can find nor could I find a paper on it. It seems no one but Arp finds it interesting. He classed it as a spiral with a high surface brightness companion on its arm. That's the blue dot at the 1 o'clock position. Though it appears it may be a foreground galaxy. I find no separate identity or info for this companion. It's just that most catalogs show "Arp 52 as a galaxy with companion". Without further data, there's no way to know if the two are related or not. Both are blue which might indicate they are interacting and thus have triggered the creation of a lot of young super hot blue stars. But without any literature to check there's no way to know.

Arp 52 is about 380 million light-years away and seen against the stars of Orion, not far from his left armpit, Bellatrix. There are three other galaxies in this image that are located at about this same distance and are thus likely part of the same group. Two are down near the bottom left corner and are very obvious reddish S0 type galaxies, the brightest two in the field besides Arp 52. The third is near the top of the frame a bit right of Arp 52 and below the brightest star in the area. It too appears to be a spiral but far more blue than the other two at the lower left and smaller as well. While I mention the lower two as looking like S0 I found no classification for any galaxy in this image, Arp 52 included.

Due to extreme cold, the set screws that hold the camera on the scope had contracted enough to allow the camera to tilt some. Due to the way it mounts to the scope it can't fall off when this happens but it can and did tilt. This meant the left and right edges of the frame were very blurred so I cropped them out. This is why the image is narrower than normal. It is still at my standard 1" per pixel. The left side was further out of focus than the right but I cropped it evenly to leave Arp 52 in the center. So you will see the stars on the left side are rather fuzzy due to this problem, especially in the upper left corner.

Arp's photo of this one is at:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp52.jpeg

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

Related Designations for ARP052

ARP053

Arp 53/NGC 3290 is located in Hydra about 490 million light-years distant according to its redshift. Arp put it in his category for spirals with high surface brightness companions on an arm. He made no comment on it. NED classes it as SAB(rs)bs pec with HII emission. The obvious feature of this one is the long arm with a blue knot (the "high surface brightness companion"). But what's really strange is that the arm is shadowed by a fainter more diffuse but disconnected arm that runs parallel to the major arm. The "companion" isn't listed as a separate galaxy at NED but then most of the galaxies in the image aren't cataloged. In fact, NED lists no galaxies within 9.9 minutes of arc of Arp 53! The only galaxy in the image with a redshift measurement besides Arp 53 is the IR source 2MASX J10360744-1721350. It is the vertical oval southeast of Arp 53 and east of the bright M (orange) star in the image toward the lower left corner. It is 480 million light-years away so likely related to Arp 53. Though it shows no distortion so likely has never interacted with it. It was discovered by Francis Preserved Leavenworth in 1886. His logs only showed the year of his discovery. And yes his middle name is Preserved.

So what caused the drawn-out arm with its shadow companion? Likely some interaction which could be due to that blue object on the arm. None of the papers I found seem to see it as a separate galaxy, just referring to the arm as having bright knots. Unfortunately, it is out of the Sloan survey field so they've not weighed in on this issue. A search turned up no likely candidate even well out of my field of view. It could be the blue blob is to blame but I'm not sold on this. I wonder if this one isn't the result of a merger. I see that as more likely to create an apparent shadow arm. There are plenty of examples of M51 type systems with a companion on the arm. None have shadow arms but some mergers do create arcs of stars that haven't yet returned to the galaxy's halo. It could be this is one that, by line of sight, happens to about follow the arm. Yeah, that's a huge reach too. Probably too much of one. So this one will have to await further imaging of it. HST are you listening?

Arp's image:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp53.jpeg

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

Related Designations for ARP053