ARP246

Arp 246/NGC 7837-8 is a pair of spiral galaxies Arp put in is very oddly named category for galaxies with the appearance of fission. As with all others in this category, I don't begin to see anything suggesting these are due to the division of what was once one galaxy. Arp apparently didn't either as his comment reads: "May not be physically connected." So why he put it here rather than in his double galaxy class I don't know. If his object had an NGC number he normally noted this yet for this pair that column in his atlas is blank. The pair was discovered on November 29, 1864 by Albert Marth.

The galaxy pair is located in Pisces. Of the two only NGC 7838 on the left has a redshift in NED. That puts it 510 million light-years away. Thus we can't begin to determine if the two are interacting. (Edit: Since this was written NED shows 7837 as being 470 million light-years distant by redshift. The difference may not indicate a real distance difference. It is quite likely these two are related but are they interacting?) While the field contains 7 NGC galaxies, including the two in Arp 246, only three have redshift values. The two show a much lower redshift. (Edit: A few more have distance or classification data at NED. The annotated image has been updated to show this new data.)

There are a lot of galaxies in the image, but only a few are listed at NED. All that are noted on the annotated image along with the three known redshift light travel distances in billions of light-years. There is one asteroid in the image, 2000 SC290 at an estimated magnitude of 19.5. Perspective has it traveling very slowly so the trail is short and bright compared to a typical 19.5 magnitude asteroid. The lack of a number usually indicates that it hasn't yet completed one full orbit. If this applies here this one must orbit out near Jupiter. It was only a bit under 14 degrees from Jupiter which is too close to be a Trojan asteroid of Jupiter.

Arp's image
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp246.jpeg

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

Related Designations for ARP246

ARP247

Arp 247 is a pair of interacting galaxies; IC 2339 and IC 2338, left to right and top to bottom. A common arm connects them. At least Arp seems to say this when he says: "Spirals have common arm, N spiral arm continues NE." The latter comment seems to refer to the southern arm of IC 2339 that goes north and continues as a faint tidal streamer far beyond the galaxy. He seems to have missed a similar streamer going mostly west and a bit north on the other side. It is fainter and out of his image. Apparently, he didn't know it was there. It is classed under his category: Galaxies (not classifiable as S or E); Appearance of fission. Odd but his comment calls them spirals then he puts them in a class saying they aren't identifiable as spiral or elliptical. I see several problems here. One is that while the arm may appear "common" to both galaxies this is possibly a perspective issue and if seen at a different angle one is likely in front of the other and we are seeing an overlapping of two separate arms. Since colliding galaxies can merge but not split as they are already separate objects this might be fusion (a merger in progress) but certainly not fission. Or is he referring to that tidal arm as splitting off? We now know these almost always collapse back into the merging galaxies though some stars may never return, most do. At least in the simulations I've seen or run.

Redshift data on both galaxies shows virtually the same radial velocity which translates to a distance of about a quarter of a billion light-years. This strengthens the idea they will merge in the future. Or already have and the light just needs a quarter of a billion years to get here to tell us. Actually, due to the expansion of the universe, it will take a bit longer than that to reach us through the ever-growing universe. The pair is part of what is known as the Cancer Cluster. The main part of the cluster is well out of my field of view to the west-southwest. Quite a few galaxies across my image have a similar distance so are likely members of the cluster as well.

IC 2339 is classed as an SB(s)c pec galaxy while IC 2338 is SAB(s)cd pec. I've not mentioned much about classification so let me go into more detail here. SB(s)c can be broken down to SB indicating a barred spiral, one whose bar is straight, if it curved some it would be SAB. The (s) means the arms that come off the bar go only one way, If they had gone both left and right from the bar then it would be (r) for ring even if that ring was far from complete. The c indicates how loosely or tightly wound the arms are. Tightly wound gets an "a" very loose gets a "d". Pec, of course, means peculiar so it sort of fits the previous classification or is thought it did before something happened to it like running by this other galaxy. IC 2338's classification as SAB means the bar is somewhat curved, not straight in that the spiral part that comes off the arms in a gradual transition rather than a sharp one as in SB class. (s) has been covered and the cd means it is looser than a c class but not as loose as a d class. And of course, it is peculiar due to its run in with IC 2339. This is a somewhat oversimplification of the de Vaucouleurs classification. Hubble's class would be simply SBc and SBcd. It has fewer divisions. Just is it spiral or elliptical or a spindle. If spiral does it have a bar and then how loosely the arms are wound. Elliptical galaxies are given a number, 1-5 depending on how elliptical they are 1 being a sphere. Spindles are just S0 in Hubble's system. Those that don't fit any of this are called irregular. De Vaucouleurs adds a class Sm which could be called a messed up spiral. Too messed up for the normal spiral classes but still recognizable enough not to be an irregular. The Magellanic Clouds would be such an example and is the reason for them to denote this class. For a good link on all of this and a lot more (big Powerpoint file) see: http://www.astro.ufl.edu/~vicki/galaxies/Lecture2.ppt There was a much better PDF version but it seems to have vanished to be replaced with the ppt file of the same URL except for the ppt extension.

The large galaxy above Arp 247 is IC 2341, an S0 galaxy also about a quarter billion light years away so a member of the Cancer Cluster. The Sc spiral down and left of IC 2341 is LEDA 142820, a 16th magnitude spiral in the Cancer Cluster.

There are 10 asteroids in the image. See the annotated image for details. IC 2338, 2339 and 2341 were all discovered by Stephane Javelle on March 2, 1896. All the action is happening in Cancer a couple degrees NW of M44.

The Sloan image can be found at:
http://astronomerica.awardspace.com/SDSS-5/IC2338.php

Arp's image:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp247.jpeg

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

Related Designations for ARP247

ARP248

Arp 248 or Wild's Triplet, named for the British born Australian astronomer (John) Paul Wild, is a triplet of interacting galaxies whose redshift puts them about 250 million light-years from us and is in western Virgo. Most sources say they are connected by bridges of stars. I'm not quite sure I agree. I really see little hint of a bridge between the left two Yes, there is a hint of a vertical bar of debris but it seems to just over-run the tidal arm of the northern galaxy without actually merging with it. The obvious tidal streamer from the middle one to the western one seems to overrun the western galaxy rather than connect to it. The tidal arm of the eastern galaxy seems to ignore its presence indicating none of its stars are involved. The streamers could lie in front of or behind the companions.

The main galaxy in the middle is MCG -01-30-033, it is also in the 2MASS IR source catalog indicating massive star formation is going on that is heating dust to create all this IR radiation. It is classed as SB(s)b: pec with HII regions. The western galaxy is MCG -01-30-032. It is classed SAB(rs)b? pec. and is also a 2MASS object and thus a strong IR emitting galaxy. Between these two and below the main tidal streamer is the near edge on spiral 2MASX J11463870-0351363. It too is a strong IR emitting galaxy. Is it involved? The one paper I found that mentions it says it is likely a distant galaxy. But gives no reason for thinking this. Though it does appear to be possibly a large galaxy which would require it to be more distant. Still, I've seen cases where this logic leads to very wrong results. So I'll just say I don't know.

The northern member of the triplet is MCG -01-30-034, Yep, it too made the 2MASS catalog. It is classed as SB(s)c pec. It's redshift, if an accurate distance indicator, puts it about 10 million light-years more distant. More likely this is just a difference in their orbital motion from the near collision and their mutual gravity and not necessarily a true distance difference.

Arp put this in his Galaxies (not classifiable as S or E): Appearance of Fission category. Again I don't see what he sees as the "appearance of fission". Only thing I can see is that it may look like the center galaxy is pulling away from the western one stretching its arm in the process. He left no comment on this one.

The triplet gets its name from (John) Paul Wild, a British born, Australian astronomer who studied this group when at Cal Tech in 1953. I can't find if he used the 200" scope but that would seem likely. Arp often drew upon recommendations from other astronomers (much like Messier) for additions to his catalog. He likely was well acquainted with Wild's work on this group.

Going north and a tad west from the western galaxy you come to a red star with a round galaxy right beside it making it look like a double star but the western one is fuzzy. This is MAPS-NGP O_614_1267245. I can't find anything useful on it. Continue north to a similar fuzzy star but without a real star beside it. This is 2dFGRS N174Z156 which is 1.2 billion light-years distant. Since this field is not part of the SDSS I'm having to go to some rather obscure catalogs to find anything on many of the galaxies.

The bright star at the top of the image is SAO 138399 a 7.57 magnitude F2 star that gave me fits when processing the image. West of it are two rather bright red galaxies. The first is 2MASX J11462460-0345433 at about 675 million light-years. The round one is 2MASX J11461879-0345353 at about 660 million light-years.

The northern part of my image is in the SDSS but it doesn't go far enough south to pick up Arp 248 so I have no SDSS image but I did turn up one taken at the University of Arizona's Mt. Lemon SkyCenter atop Mt. Lemon which has excellent seeing I lack here.
http://www.caelumobservatory.com/gallery/wilds.shtml

Arp's image is at:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp248.jpeg

14" LX200R @ f/10, L=5x10' RGB=2x10', STL-11000XM, Paramount ME

Related Designations for ARP248

ARP249

ARP 249 is a pair or trio of interacting galaxies known as UGC 12891. Arp put them under his Appearance of Fission category. I've never figured out if he really thought they were splitting or just gave that appearance. He later decided quasars were ejected from galaxies but was more mainstream at the time he put the atlas together. His comment indicates he sees three galaxies here while some catalogs only see two and a plume or jet depending on who you read. It does have three listings in the PGC catalog 25, 200388 and the plume or galaxy being 1679585. Arp says: "Straight connection from faint material on east to middle galaxy." Which he sees as the appearance of fission I don't know. One note at NED refers to this eastern plume as "arrow-like projection." So what is the condensation in the plume? None of the catalogs at NED list it but I can see why Arp considered it a third galaxy. The Sloan survey, nor any other general survey covers this part of the sky so information is hard to find. NED lists the distance to the two main condensations as 511 and 512 million light years. While the pair appear to be elliptical galaxies NED doesn't even try to classify them.

Besides a dearth of information on Arp 249 that also applies to most of the field. Only one other galaxy in the image has any redshift data with the vast majority of the galaxies not even listed at NED. In fact, one of the few carries the note that it really is only a field star! The edge on spiral without much of a dust lane northwest of Arp 249 that's above a rather bright blue star is PGC 00004. Since that catalog starts at 0 hours right ascension this galaxy almost marks that point being only 3" of time east of that line. NED classes it simply as Spiral (written out not S as you'd expect. The red-shift puts it at 188 million light years.

A dozen or so other galaxies in the field are in the 2MASX catalog of IR galaxies but without even so much as a magnitude estimate. Apparently, no one looks very hard at this part of the sky.

Arp's image:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp249.jpeg

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

Related Designations for ARP249

ARP250

A few Arp galaxies are very photogenic, Arp 85 (M51) for instance, most are at best interesting. Then there are those so far away or so small they are the photographic duds. Unfortunately, Arp 250 falls into this category, in this case, because it is so very small yet could be two colliding small galaxies.

While there are two galaxies here only the one to the west is considered to be Arp 250 which he classed by Arp under Galaxies (not classifiable as S or E): Appearance of fission. It does indeed appear to be a galaxy that has been cut in half right through the core. Or else it is two spirals about to collide. It is only about 70 million light-years distant, two and a half times closer than Haro 1 in the lower left corner. It is a rather small galaxy. The only catalog entry for its "companion" to the east is in the PGC where it is listed as #2063674 at magnitude 17.5. My image is poor but it appears distorted so may be involved. There's just not enough information to know. In all, there's a dearth of data here. I figured its odd double nature should have generated some papers but I found none. Heck, Arp apparently didn't have anything to say on this one. At least I couldn't find any comment from him on it. Nor any by anyone else other than a visual sighting with a 25" scope.

After I wrote the above paragraph I'm finding some sources, such as NED consider the eastern two armed spiral as Arp 250. Same happens when I enter it into the STScI DSS server using SIMBAD to resolve the coordinates. Yet SIMBAD itself gives the western galaxy. Arp's image is framed to give equal prominence to both. The only object showing anything that could be construed as splitting would be the two colliding galaxies to the west.

Little information is available on anything in the image. The very blue tiny galaxy west (right) of Arp 250 is HS 0732+3529 at the same distance, 180 million light-years as Haro 1. HS stands for Hamburg/ESO QSO Survey. Apparently, it looked for compact blue objects as likely QSO candidates and found this galaxy in the process. NED lists no other catalog entry for it.

There's another very blue galaxy SE of Arp 250. Appears to be a spiral. Oddly no catalog I checked includes it. Is it too at 180 million light-years? I have no idea. I can't even give it a catalog entry.

Galaxy in Southeast corner is Haro 1/NGC 2415 classed by NED as possibly an irregular Magellanic galaxy. Redshift indicates a distance of about 180 million light-years. Seems large for a dwarf and while the spiral structure is distorted I don't see it as an irregular galaxy. Haro galaxies are blue with emission lines. It is thought paired with one or two other galaxies described as 22 minutes north which puts them out of my FOV. The only candidate, out of my field, I can locate is UGC UGC 03937 but it is 23 minutes NNE with a redshift distance of 190 million light-years. HS 0732+3529 is only about 17.4' away so may not fit though its distance and very blue color would seem to say otherwise. Only catalog entry anyplace for the one (or is it two) blue galaxies just to the west of Haro 1 is PGC 213406 with little other information. I see a wisp of stars below it but not quite connected to it. No nucleus to it. So is it a tidal arm pulled from this galaxy or another galaxy entirely, just one with no defined core? One reason Haro 1 looks distorted is there are three stars superimposed on its arm structure making them look more distorted than they really are. You have to look closely to see them. I wouldn't have noticed them except for one paper that mentioned them.

Haro 1 seems to have confused the keepers of the Hubble data archive. I checked the archive to see if Hubble had imaged Arp 250. I was happy to see two images. At least I'd have a black and white image. Nope. It was Haro 1. So I tried other catalog names for Arp 250. All brought me back to Haro 1 -- oops. So I tried Haro 1 and got a lot of images of it, none the two filed under Arp 250. Interestingly the mono image labeled Arp 250 was the best data. I then took color filter data from Haro 1 data and made the attached Hubble image of Haro 1. It's a tad better than mine. Though is it billions of dollars better? Hmm. NGC 2415/Haro 1 was discovered by William Herschel on March 10, 1790. It is in the second Herschel 400 observing program where it is described as "tiny." With a diameter of about 50,000 light-years, I'd not say it is "tiny." Just that it appears tiny from our distance but it is far larger than the two galaxies that make up Arp 250.

Just off the bottom left edge of the image is the galaxy cluster, ABELL 0590. There is a possible QSO just on my image. It is only 2.5 million light-years away. NED says it is a galaxy, SIMBAD says QSO. In my image, it appears to be a very orange galaxy right along the lower left edge of my image, NE of Haro 1 so I have to vote for the galaxy designation. Likely one with a very active nucleus.

http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp250.jpeg

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

Related Designations for ARP250

ARP251

This is one of Arp's least photogenic catalog entries. Big and bright it's not! You'll need the 2x enlarged view to see much detail in these apparently extremely distant galaxies.

Arp 251 is a triple galaxy in western Cetus. Arp classed it under Galaxies (not classifiable as S or E): Appearance of Fission. Probably because the two spirals appear connected and "trying" to split apart. More likely their arms overlap as seen from our point in the universe. Arp's comment: "Outside arms diffuse and bifurcate." The northern galaxies "bifurcated" arm appears more like a true arm and a detached star cloud. The southern arm appears split in my shot more than Arp's for some reason.

The northern galaxy is cataloged as 2MASX J00534840-1351148. The Kanipe/Webb book lists it as MCG -02-03-037 but NED says this is all three as it lists it as a triple. In any case, NED has little on it, not even a magnitude. The southern galaxy is 2MASX J00534765-1351358 and is listed at magnitude 15.1 but that's in near-infrared light (I band) and may not say anything about its visual magnitude. The third member to the southeast is anonymous, only being listed in the UK's automated plate measurement catalog as APMUKS(BJ) B005119.43-140753.8 which gives it a magnitude of 17.8 but no filter is listed. A note at NED on Arp 251 says the southern and southeastern galaxies are 16th magnitude. It doesn't give an estimate for the brighter northern galaxy. That's the extent of what I could find on these three galaxies -- virtually nothing. No distance measurement, little spectral data and fuzzy magnitude data. That's it.

Edit: Since the above was written I found one amateur page that cited a z value of 0.075300 (22575 kps). That would translate into a distance of about one billion light-years. Does that make this the most distant of his entries? Some say it is the most distant but as I can't find a redshift for others, I can't verify this.

The near edge on galaxy to the northwest is 2MASX J00533671-1349541. It has a magnitude listed at 16.4 and a redshift distance of just over 700 million light-years. The magnitude lists no filter. It is larger in angular size than the galaxies making up Arp 251. This could mean they are further away but it could also mean they are smaller galaxies in the first place and are really closer. There's no way to know. Most of the other galaxies in the image are only listed in the APMUKS catalog, only the one galaxy has any redshift data.

Even my The Sky database for Arp galaxies got confused and centered me on the near edge on spiral to the upper right. I checked this with SIMBAD and the DSS II plates which centered on a spot halfway between the two. I went with my database without checking further so it isn't as centered as I'd like. Also, this is about 13.7 degrees south nearly at my normal 15 south limit so seeing isn't very good. That's what I get for moving north to get dark skies instead of New Mexico or Arizona.

Arp's image: http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp251.jpeg

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

Related Designations for ARP251

ARP253

Arp 253 is a pair of probably interacting galaxies located near the western border of Sextans about 100 million light-years distant. At least that's the distance to the western galaxy which is also cataloged as UGCA 173. A secondary distance estimate puts it at 90 million light years. Since galaxies have motions besides that of the expansion of the universe the difference is really quite normal and expected. It is classed by NED as SB(s)dm? The eastern galaxy is UGCA 174. There are no distance estimates for it but likely it is truly interacting with UGCA 173 and thus at the same distance. It is classed as SB(s)m? Arp's only comment indicates there may be some stellar resolution or else HII regions. At that distance, the latter would most likely be what he was seeing. Arp classed it under Galaxies (not classifiable as S or E); appearance of fission. As with most galaxies in the classification, I don't seem to understand why he says that. Does he mean the two galaxies look like two rod-like bacterial splitting? They often move around like two train cars before splitting completely. Or is he referring to the various parts of UGCA 173?

The reddish round galaxy SW of Arp 253 is 2MASX J09430672-0518514. I have no information on it. Far more interesting is PGC027825, the "large" galaxy south of Arp 253. Its redshift puts it also at about 100 million light years indicating it is part of the same group. It is not mentioned by Arp but sure looks peculiar enough to have made his catalog. NED classes it as SB(s)d pec. It may also have interacted in the past with other galaxies in the group.

Above Arp 253 about the same distance as MCG -04-25-033 is south of it is 2MASX J09432459-0510450, a small round galaxy of unknown distance or classification. Toward the upper right corner is another orange galaxy just below and right of a blue star. It is 2MASX J09423777-0509328 at 750 million light years.

The orange galaxy near the left edge several minutes of arc below the top edge is 2MASX J09442604-0511330 at about 800 million light years. Above it, right in the top left corner is 2MASX J09442771-0508030, yet another IR strong galaxy. It too is at 800 million light years.

While there are a lot more galaxies in the image only those in the 2MASS survey are cataloged and I've listed all with redshift data. SDSS hasn't covered this region nor has Arp 253 been imaged by the HST.

The asteroid is (84901) 2003 TF13 at an estimated 17.9 magnitude.

The last blue exposure was 10 seconds too long as the object reached the mount's meridian limit. So there was a short blue trail on each bright star. I didn't even notice it until I was about to post this and suddenly saw it on the bright star to the lower right. At first, I thought it another asteroid trail until I realized fainter stars had similar trails. I only cloned out the bright one so the fainter ones are still there if you look closely enough.

Arp's image is at:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp253.jpeg

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

Related Designations for ARP253

ARP254

Arp 254 is a pair of interacting galaxies, NGC 5917 (MCG -01-39-002) and MCG -01-39-003/PGC 054817. They are located in Libra, about 96 million light-years away. Arp put them in his category for Galaxies: Appearance of Fission. I can't fathom how he sees these two as appearing to be dividing. Arp had no comment on the pair to help shed some light on this. NGC 5917 was discovered by John Herschel on July 16, 1835.

NGC 5917 is classed as Sb pec? and is the northern galaxy. It has a rather large faint outer halo and is somewhat disturbed. It is listed in the 2MASX catalog of InfraRed objects so likely has some dust heated by star formation we can't see. While sometimes a sign of interaction that isn't necessary. The southern galaxy with the two huge plumes is MCG -01-39-003. Redshift puts it slightly more distant but this is likely just due to relative motion rather than a real distance difference. It is classed as S0 pec. A note at NED indicates the northern plume reaches NGC 5917 and thus is a bridge. I certainly don't see that in my image nor in Arp's but if there would explain his fission category as he uses it mostly for galaxies that are apparently connected by a tidal stream of stars. The note also notes the system is "perfectly isolated". Maybe but I'd like to know more about LEDA 1017437 to the south of MGC -01-39-003. It is off the other plume and at 800 million light-years. With the plume headed toward it, I find it a "galaxy of interest", as the detectives say.

Kanipe and Webb have this to say about the pair. "This strange pair of galaxies is connected by a tenuous bridge, visible both in the Arp Atlas photograph and Richard Miller's image (above). Close examination shows that the interiors of both galaxies have been stirred by experience. Since the system is totally isolated in intergalactic space, the bridge and the disturbed appearance of the disks suggest a galactic sideswipe." Richard Miller's image, which includes a 2005 supernova is at http://www.338arps.com/arp_254.htm

I agree a sideswipe likely is the cause, however. The note above agrees to the note at NED. Could that note be the source of their comment? The note dates to 1963 so was likely known to Arp at the time he took his image. Could it also have influenced him to put it in the fission category? NED has nothing newer on the system which bothers me. Link to the note: http://ned.ipac.caltech.edu/cgi-bin/nph-datasearch?search_type=Note_id&objid=40559&objname=NGC%205917&img_stamp=YES&hconst=70.5&omegam=0.27&omegav=0.73&corr_z=1&of=table

When I first wrote this my monitor showed no sign of the bridge in my image nor any other including the ESO image below. Since then I've changed my mind as I do see it now in my image as well as the ESO image. Apparently, I was distracted by the hook to the arm thinking it hooked back which it seems to have done but some stars continue up in a very faint connection.
http://www.eso.org/public/news/eso0622/

Color data in my image is very poor. The object is low in my skies and spring fog off the lake really tore up the color frames. I took the color data over three nights under very different seeing conditions. I took all three colors each night but fog ruined each color 2 of the three nights. Only the color I took first that particular night got through. Even then green was really clobbered. I used it but wonder if I should have tried a pseudo green made from the red and blue instead. I'm so far behind in my image processing I didn't try it both ways.

The field is out of the Sloan Survey area but the VLT image is far better anyway. Still, I wish it covered the southern plume as well. Without Sloan data, only the "big and bright" galaxies in the field have distance data. I've included an annotated image with the distances to these in billions of light years. Only 12 galaxies in my field are even cataloged at NED, 7 with redshift data. Pretty meager field. I'm used to thousands in the field being cataloged.

Arp's image
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp254.jpeg

ESO-VLT image at full size
http://www.eso.org/public/archives/images/screen/eso0622a.jpg

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

Related Designations for ARP254

ARP255

Arp 255 is another in his category Galaxies (not classifiable as S or E); Appearance of fission. In this case, it does look as if an arm broke off though that is likely only illusion. Even Arp considers it a separate galaxy but does believe the faint tidal arm to the north is really the continuation of an arm of the bigger galaxy as he notes: "Faint arm extends beyond high surface brightness companion." The pair is otherwise known as UGC 05304. They show a red shift indicating a distance of about 565 million light-years. NED calls the smaller one a "late spiral" and the larger simply S? probably indicating there's no agreement as to what type of spiral it is rather than if it is a spiral as it is obviously one. Looks rather like SBc pec to my untrained eye. The arms are unusually red for a spiral except for a detached very blue segment that may be mostly massive star clusters but otherwise, show no visual hint of star formation due to the interaction. Though it may be hidden behind dust. There seems to be little on this pair. Down and to the right of the pair is CGCG 035-075 which has about the same redshift and is obviously part of the same galaxy group. Directly west past an orange star is a rather bright very blue "star". It is the quasar [HB89] 0950+080 at 9.3 billion light years. Directly below CGCG 035-075 is a large faint, nearly colorless smudge of a galaxy. It is LSBC D709-10, an irregular Magellan like galaxy about 150 million light-years distant.

The big galaxy to the left is UGC 05308. It appears highly distorted as well but it likely did not interact with Arp 255 as its redshift shows a distance of less than half the distance at 260 million light years. It too is classed S? by NED. I'm surprised Arp didn't put it in his catalog as well. A couple of the small blobs in the upper part of it are listed by the SDSS as being separate galaxies with no redshift data. One is a short linear fuzzy patch in its NW merging with a star cluster in the arm. The other is the star-like blue object directly east of this feature. It's possible these are just parts of UGC 05308 rather than separate galaxies. Or they could be merging with it and the cause of the tidal distortion in the galaxy or they are far behind it. Without redshift data, I can't tell. Edit: Since the above was written the short linear fuzz patch has been given a distance of 540 million light-years using the Friend of a Friend method. The other blob has a redshift of 550 million light-years. Both are considered by NED to be part of the Arp 255 group.

Below it is the lenticular-like galaxy 2MFGC 07657. It is at a redshift distance of about 545 million light-years so could be part of the Arp group. Above it is another lenticular-like galaxy but smaller that is at about 550 million light-years and another likely group member, SDSS J095323.73+075113.7.

The round orange galaxy southwest of 2MFGC 07657 is 2MASX J09531866+0748067 at 560 million light-years it is likely yet another member of the Arp 255 group. The smaller round galaxy just below 2MFGC 07657 is SDSS J095325.05+074859.9. It is much further away however at 800 million light-years.

The rather large blue galaxy top center is LEDA 087189, a 17th magnitude Sd galaxy about 140 million light-years distant.

I found several asteroid tracks in the image. I was perplexed though why one seemed fuzzy. When I ran an asteroid check on the image at the Minor Planet Center I got my answer. It is a newly discovered periodic comet (12/31/2008). I've noted the 6 asteroids and the comet on the annotated version of the image. Magnitudes are estimates of the Minor Planet Center. Magnitude estimates of the comet toward the end of March 2009 when this image was taken vary by 2 magnitudes. The Minor Planet Center made no estimate so I didn't include one. You can judge somewhat by the other asteroids but remember a fuzzy object is a lot brighter than a point source like an asteroid and speed of motion dims the trail the faster it moves. The faintest asteroid at magnitude 21.1 is right at my limit for a moving object. I may not show on some monitors. Note that some of these estimates appear in error. With one listed at 20.0 appearing fainter than two estimated to be even fainter. An asteroid doesn't get a number until it has been followed around a complete orbit. This is why some have numbers and some don't.

Maybe I should title this image James Bond meets Arp 255. Well Ian Fleming anyway, yes that Ian Fleming. That's the brightest asteroid in the image! No space so it's Ianfleming on the annotated image. The naming citation reads: (91007) Ianfleming = 1998 BL30
Ian Lancaster Fleming (1908-1964) was a British writer and journalist. Fleming is best remembered for creating the character of British Secret Service agent James Bond ("007") and chronicling his adventures in twelve novels and nine short stories.

Limiting magnitude for this image is about 22.6, rather typical. The galaxies are in southern Leo southwest of Regulus almost to the Sextan's border.

Arp's image
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp255.jpeg

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

Related Designations for ARP255

ARP256

Arp 256 consists of two interacting galaxies; MCG -02-01-051/PGC 001224 (lower) and MCG -02-01-052/PGC 001221 (upper) at a distance of about 355 million light years. Arp classed them as; Galaxies not classifiable as S or E; Appearance of fission. Using standard galaxy classification the upper one is classed as SBc pec while the lower as SBb pec? So both are considered barred spirals. One note says of the upper galaxy; "It is possible that it alone consists of two overlapping galaxies." Hubble has taken an excellent image of this pair, it is at: http://www.spacetelescope.org/images/heic0810ag/ I'm not sure if it answers the question about it being two galaxies or not. That blue knot between the cores of the two galaxies may be a third galaxy. It carries a redshift that is a bit higher than either of the two galaxy cores. It is about the same as the smaller area of blue stars north of the core of the upper galaxy. Thus there seems to be an overlay of blue stars with a slightly greater redshift (by about 40 to 80 km/s). Whether this is a separate system I don't know. More likely the difference is just due to rotation of the galaxy in a plane tilted a bit away from us. The lower galaxy MCG-02-01-051 has a very interesting tidal tail to the west and in the Hubble image, it too has some of these super hot blue stars that may really be related to the other blue stars rather than the galaxy itself. Note how wild its core is as seen by Hubble.

The entire field is rather interesting and contains one of the most distant galaxies I've ever imaged directly, It's the distance of quasars, not galaxies. Per NED it's redshift puts it a bit over 10 billion light-years away! Did galaxies large enough to shine at 20th magnitude exist in a 3.5 billion year old universe? That seems pushing it, though Hubble has shown large galaxies coming together far faster than we had expected. There's one "but" in this. Seems the redshift distance has been determined photometrically rather than spectroscopically. Thus there's room for a very large error if some assumptions are wrong. The galaxy is directly below Arp 256 near the bottom of the page. Many more distant galaxies and a couple quasars (one quasar candidate is even further away than the galaxy but not by much. There are two asteroids in the image as well. Rather than try to point all this out I've just attached a second annotated image. Quasars are noted with a q in front of the distance. The other distances are for galaxies.

This pair is located at the western end of Cetus the Whale and thus is rather low in my sky reducing my ability to see fine detail. The image is a bit fuzzier than I'd like because of this.

ARP'S IMAGE
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp256.jpeg

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

Related Designations for ARP256