ARP180

Arp 180 is a pair of interacting galaxies. The second is the small blue dot near the core of the main galaxy and right on the arm. In fact, much of that arm may be a plume from this second galaxy thus explaining why this arm is so much brighter and bigger than the northern arm which barely registers in Arp's photo. I find no catalog that names them separately. They are known by several other names MCG -01-13-034 and VV 822 seem the most commonly used. This is the first Arp galaxy I can find virtually nothing on. No distance data at all. Arp's comment is: "S arm kinks back, thin filament connects nuclei." What little I found on it also only mentioned the south arm. I don't know why the north one gets so little respect but it is very faint, nearly in the noise level of my image. The filament that Arp says connects the two looks little different from the short bright arm seen in Arp's image on the other side of the larger galaxy. So the "connection" may be due to perspective and not a real connection.

Also, is it possible the arms trace the path of the little galaxy? That is, it starts to lose stars as it comes in from the north, loses more and more as it passes behind the larger galaxy then loops back toward the core. Seeing the last part more edge on makes it brighten as it closes in on the core. Is it on a death dive or just flying by above the core destined for another trip or two before finally either losing all its stars or being devoured. Either way, its stars are likely destined to join the main galaxy. All this is just my guess but since the core of the main galaxy isn't oriented as if to support these "arms" It makes it a bit more likely to my eye to be a possible explanation. Also if on a death dive the gravity of the little guy could pull a tidal plume to elongate the larger galaxy creating the similar brightenings on either side to the NE/SW.

The galaxy east (left) of Arp 180 is 2MASX J04533482-0448443 at about 900 million light years. The rather bright large galaxy near the left edge below center is LEDA 146644. Again, no information. The field has about a dozen 2MASX IR strong galaxies in the image but only the one already mentioned has any distance data. Most of the rest are anonymous.

Arp's image
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp180.jpeg

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

Related Designations for ARP180

ARP181

Arp 181 is a pair of NGC objects in northern Draco about 429 to 440 million light-years away. Arp put it in his category for galaxies with narrow filaments. In this case, he is apparently referring to the long drawn out tidal arm going to the west of NGC 3212. His comment reads: "Long faint filament extends westward from south arm." This certainly fits NGC 3212, the galaxy on the right (west). But then the confusion sets in. Arp says he is referring to NGC 3210! NGC 3212 is indeed the galaxy with the long straight filament but NGC 3210 is just a double star above the faint part of the arm. The other obvious galactic companion lies to the east so has the higher designation of NGC 3215. The NGC Project says this about NGC 3210: "NGC 3210 is a close double star about an arcminute west-northwest of NGC 3212. WH's description is appropriate, and his position (for all three objects; the third is NGC 3215) is good. There is another star of similar magnitude about 23 arcsec preceding the double; is it possible that WH glimpsed this, too? If so, it would probably have added to the illusion of nebulosity. - Dr. Harold G. Corwin, Jr." It is just the two rather bright blue stars north of the filament. Arp's image of Arp 181 cuts off the eastern side of NGC 3215 but does include the double star. So was he meaning 3212 and 3215 when he said 3210 and 3212? All papers seem to think so. But if that is right it is the only image of all 338 entries to fail to include all of the galaxy(s) involved. Since he was so meticulous in his images I find it odd he failed to include all of the objects. In any case, I'll go with the majority, besides, if I left out 3215 I'd not have much to talk about.

NGC 3212 is classed by NED as S? as SB by the NGC Project and SBb?? by Seligman. I really don't see a bar, just a bright spot on one side of a round, typical core of a SA spiral. Redshift puts it at 440 million light-years. NGC 3215 is classed as SB? by NED, S by the NGC Project and SBbc? by Seligman. So does it have a bar? I see a slight hint of one mostly due to how the arms begin a bit out from the core as if there's a rather obscured bar present. It would seem to also fit Arp's category for three armed spirals as there appears to be a faint southern arm beside the closer in the brighter southern arm. NED gives it a redshift putting it a bit closer, 429 million light-years. That would make it some 140,000 light-years across, a very large spiral. Still, could it pull out the tidal arm of NGC 3212 without it showing much distortion? Or is the tidal arm of NGC 3212 due to something it digested or interacted with in the past? I tend to favor the latter.

William Herschel found is all three NGCs 3210, 3212, 3215 on September 26, 1802. HE got two out of three right. None are in the Herschel 400 observing programs.

The only other galaxy in the field that NED has redshift data for is MCG +13-08-013 near the right edge of the image just above centerline. It is listed at 1 billion light-years. NED makes no effort to categorize it. It is huge at about 200,000 light-years in diameter. I'm surprised it isn't the core of a galaxy cluster but apparently, it is a huge lone galaxy. Maybe it ate all its companions. That would explain its size.

With nothing else in the field with any data to speak of and many of the galaxies not even listed in NED, I didn't prepare an annotated image. I lost 4 L images to clouds and horrid seeing as well as 4 color frames. The weather has been a constant menace in 2012 with many images being affected by it I'm finding. I wanted to go much deeper but the weather had other ideas. This results in the image being noisier than I was expecting.

Arp's image:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp181.jpeg

14" LX200R @ f/10, L=4x10' RB=3x10' G=2x10', STL-11000XM, Paramount ME

Related Designations for ARP181

ARP182

The spike of Arp 192 turned out to be a false alarm and was only an asteroid. But Arp 182 has an even longer and almost as narrow spike that too is virtually straight and darned hard to explain. It also looks artificial and unreal but this one does really exist.

Arp 182 is also part of a group known as Hickson 96. It is a tight group of 4 galaxies about 375 million light-years away. The main one is NGC 7674, Hickson 96A, classed as SA(r)bcP. It is interacting with NGC 7674A or Hickson 96C. The result is a rather normal small plume to the north with a detached (in my image that is) plume further north. The really strange one is the narrow, well-defined one heading in a nearly straight line to the east-northeast. Since it barely shows on Arp's image I didn't see it before my image started to come in. After the first frame, I was sure I had a reflection. I moved it on the sensor but the "reflection" moved like a real object so I went back to my original position and finished the shoot figuring I'd just deal with it in processing. It looked too real when I got around to processing it over 6 months later. A bit of research was called for, looking at Arp's notes, in this case, turned up the fact he had noticed it. His comment: "Long straight, very faint filament like bow wave from companion." Also, I should have noticed his classification under Galaxies: Narrow filaments. I just thought he meant the stuff on the north side. Hubble has taken a great image of this galaxy. It is oriented with east down rather than to the left as my image is. Oddly the filament is dimmer on that image than mine yet his shows the filament I see as detached as connected to the galaxy. I don't know why the difference other than it may be due to my far lower resolution. In fact, it appears the "detached" filament is really an extension of the outer arm much like in the Whirlpool Galaxy, M51, Arp 85. It's the short one tucked in between it and the galaxy that may be harder to explain. Is it part of the other arm? How the long straight eastward filament fits in I just don't know. It does appear to curve into the companion which has a tidal plume at the other end. Problem is the plume is somewhat blue and the other plume is rather red. While the companion has some gas and dust was it enough to trigger such massive star formation in the plume? Apparently, it was.
Hubble's image: http://www.spacetelescope.org/images/heic0810bp/

The third member of the group shows in the Hubble image with some detail. In mine, it is just a small blue oval to the left of NGC 7674. It is Hickson 96D or PGC 71507. The 4th member doesn't fit in the Hubble image frame. It is further east, left, and is NGC 7475, Hickson 96B. Most sources say it is an SAB(s)0 galaxy. NED agrees one place and another says it is E2. It sure has the color of an elliptical galaxy. S0 galaxies usually are white to slightly orange in color. NGC 7674 and 7675 were discovered by John Herschel on August 16, 1830.

There's little information on the other galaxies in this area. The odd spiral directly above NGC 7674, near the top edge of my image, that appears to have but one spiral arm in a otherwise amorphous disk is PGC 071506/CGCG 406-113. It is a bit further away at nearly 550 million light-years. The oval ring galaxy to the southwest is 2MASX J23273713+0841028/PGC 1351684. I have no distance data. The bright galaxy in the upper left corner is PGC 071560/CGCG 406-117, a spiral that also appears to be part of the same group as it too is located at about the same distance.

The edge on spiral at the right edge in the center is PGC 071461/2MFGC 17605. It is only 260 million light years away so probably not related. The galaxy at the very bottom center edge is 2MASX J23275583+0835513. I have little on it. It appears to be another ring galaxy, round this time. Unfortunately, this field is out of the SDSS survey area so most galaxies are uncatalogued. There's an interesting pair of small very blue apparently interacting galaxies NW of Arp 182. Unfortunately, like most in this image they are uncatalogued (Edit: They now are listed as Ultraviolet sources but no distance, see annotated image). A similar pair is to the right of the oval ring galaxy 2MASX J23273713+0841028 halfway to the edge (Edit: They too are now listed as Ultraviolet sources but without any distance). There's also an X-ray galaxy with a very active AGN in the image, HELLAS 209. I've included other galaxies without distance data in the annotated image.

The image contains three asteroids. The brightest to the southeast of the center is (60171) 1999 UP47 at an estimated magnitude of 18.2. Much fainter to the southwest of center not far from the bottom halfway from the center to the right edge is 2005 TF1 at magnitude 19.3. The lack of a number indicates it hasn't yet been observed long enough to make one trip around the sun. (EDIT: It has now received its number and is (272397) 2005 TF1) The third is a bit brighter and is east and a tad north of NGC 7675. This is now my 3rd unknown asteroid. I really do need to check these for unknown asteroids ASAP rather than 6 to 9 months later. It will stay undiscovered for a while longer it appears. Edit: It has now been discovered and is now known as (454899) 2015 TR99. It was previously known as 2004 TN248. Why I didn't pick it up in 2009 when this was written I don't know. Could be it was lost for a while. Oddly it is in the Minor Planet Center database twice. Once with the number and once without. The entry without an number is shown at a position well northeast of the correct position which is shown by the entry with the number. Both show it with a magnitude that is about a full magnitude too dim. I'm used to these estimates being a bit off but never this far wrong. The position, speed and direction of its motion all agree to the prediction so I'm sure this is the right asteroid.

Arp's image:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp182.jpeg

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

Related Designations for ARP182

ARP183

Another twofer deal in Arp galaxies located in Canes Venatici, about 3 degrees northeast of M3. Arp 183 on the left is UGC 8560 and Arp 36 on the right is UGC 8548. Both are about 240 million light-years distant. Both appear highly distorted yet are cataloged very differently by Arp. This image was taken through some haze for 4 of the 6 luminosity frames so doesn't pick up the faint parts of the galaxy as well as I'd have liked. Another I should revisit but probably won't.

Arp 183 is in Arp's class of galaxies with narrow filaments. Apparently he is referring to the very faint spur above the apparently drawn out arm. At least that's what his comment probably refers to when he says: "3 faint patches constitute third arm or filament." The patches are better seen in his image. The two galaxies along the long drawn out arm of Arp 183 are SDSS J133451.48+312306.9 of unknown distance and 2MASX J13345139+3123014/SDSS J133451.36+312301.3 at 1.5 billion light-years. The latter is obviously not related to Arp 183. The former, if at the same distance as Arp 183 seems way too small to be involved. NED classes Arp 183 as an Sb spiral about 240 million light-years distant. The best candidate for what distorted Arp 183 is nearby Arp 36 which is also apparently distorted.

Arp 36 is, like Arp 183 about 240 million light-years distant. It is classed as SB? Arp put it in his Spiral Galaxies: Integral sign class. Though it makes a rather poor integral sign to me. His comment: "Knots in arms approach appearance of small companion." I would certainly agree with that comment. In fact, some catalogs do list the brightest knot in the eastern (left) arm as a separate object. Oddly, a note at NED under Arp 36 actually refers to Arp 183 when it says: "SB with a double companion at the end of the single developed arm." As shown above, at least one of these "companions" is a distant background galaxy. Another note, this one on Arp 36 asks the question "Two cores?" I don't think so. This other bright object seems, in my image, to be a blue knot of new massive stars at the end of the western bar where the arm starts. There's a similar dimmer one at the start of the eastern. Several others are visible as well. Such massive star formation is common in near galaxy collisions as may have happened here. Both galaxies certainly show this effect.

The tight trio of galaxies below Arp 36 consists of WAS 75 at about a half billion light-years and 2MASX J13341649+3117095 at about three-quarters billion light-years. The third galaxy is SDSS J133417.21+311718.0 distance unknown. Below is small S0 like spiral SDSS J133417.57+311645.5 also distance unknown. The two with unknown distances are labeled with a question mark. West of this group is a pair of very red objects. The bright one is 2MASX J13340124+3117057 at 1.5 billion light-years. The SDSS catalog lists the western one as a 20th magnitude star. Its PSF doesn't look like a star in my data. Looking at the SDSS image I tend to doubt the star label but that's what I've labeled it in the annotated image. It could be the halo of the galaxy is causing the confusion so I'll reluctantly defer to the SDSS.

Below the above galaxies is, the IR strong galaxy 2MASX J13341158+3114204 at 1.5 billion light-years. It is classed as S0. It's very unusual for an S0 galaxy to have the star formation in its core needed to reach the level of an IR galaxy. Also, it must be huge to appear so large at such a distance. A quick calculation assuming it is fully face on to us puts it at about 160 million light-years in long diameter. I can't recall an S0 galaxy that large. Sure would like a closer look at this one.

Near the left edge is the distorted galaxy SDSS J133539.83+312336.1 at 800 million light-years. It is partly hidden behind a bright star, unfortunately.

There's one asteroid in the image, (239730) 2009 BL170 at an estimated magnitude of 19.4. It is moving in pro-grade motion rather than retrograde as it was taken early in the morning. It also shows how conditions improved during the image. The first part of the trail (long part) is dimmer than the shorter later luminosity images. Dawn was breaking so I couldn't get any more and never went back. The gap is due to the taking of the color frames.

Arp's images:
Arp 36
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp36.jpeg

Arp 183
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp183.jpeg

14" LX200R @ f/10, L=6x10' RGB=2x10'x3, STL-11000XM, Paramount ME

Related Designations for ARP183

ARP184

This is a reprocessed Arp 184/NGC 1961. Problem is it is at nearly 70 degrees so spends nearly all its time in my Polaris Tree. When I took this data over 2 years ago I had to do so over many nights. Even then trees (pine needles anyway) crept into the image making a mess of the stars and the background. Flats don't compensate for pine needle obstructions! My ability to handle this was limited back then. So I decided to reprocess the image using my improved skills and larger tool set. While I now could deal with the stars and background better there's a loss of resolution due to diffraction effects of all the needles I couldn't eliminate. The trees have continued to grow so doubt I can even do this well again unless I do some trimming. Since they are 100 feet tall that is a bit beyond my ladder's reach and I'm too old to try climbing them. Even a cherry picker can't reach the branches I need to reach. This will have to do.

This time I was able to bring out the many HII regions in this galaxy. Considering it is about 180 million light-years distant these must be huge compared to those we normally see in galaxies. In angular size, they are about the same as those in M101 at only 25 million light years. The distortion to this galaxy is very hard to explain. While it is a member of a small group of galaxies at the same distance (the three largest other galaxies in the image are members of this group) none show any hint of distortion so didn't cause the distortion. The other often cited reason would be a merger but the papers I found say this isn't likely. Maybe not but either this guy is intrinsically distorted or the product of a long-ago merger. I prefer the second choice. NGC 1961 was discovered by William Herschel on December 3, 1788.

Out of the Sloan survey field, NED has distance data on only the three other members of its group in the image and one quasar at 7 million light years very near the galaxy. It's faint and I won't try to point it out. Those interested can look it up at NED or download the DSS image of it. It is IXO 29. Which stands for "Intermediate-Luminosity X-Ray Object."

Edit: I've now made an annotated image that shows what few have distance data at NED. Also since this was taken I had to remove the pine trees as they were in danger of falling on the house or observatory but so far I've not retaken this object.

Arp's image
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp184.jpeg

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

Related Designations for ARP184

ARP185

Arp 185/NGC 6217 is in Arp's class for galaxies with narrow filaments. Though I don't see any in this case. Arp's comment doesn't help much. It read: "Condensed nucleus, faint outer arms less curved than inner arms." Kanipe and Webb seem to indicate he may be referring to the brighter segments of these faint outer arms. They are about the only part of the outer arms visible in Arp's image.

Arp 185/NGC 6217 is located in Ursa Minor just above the bowl of the little dipper and is about 60 million light-years away. Redshift says 61 which may be rather accurate in this case, at least the HST folks give this figure. This was the first image taken with the ACS camera after the last repair mission got it back in working order. The image is at: http://apod.nasa.gov/apod/ap091228.html . The field doesn't include the faint outer arms, however.

It is classed by NED as (R)SB(rs)bc; HII Sy2. The R and (rs) would indicate a ring structure. The SBbc means a barred spiral with arms intermediate between those of b and c structure (a is tightly wound while d is wide open arms. HII means lots of HII emission which is obvious in the Hubble image. Only the large region at the south end of the bar shows as pink in my image though other show as blue due to the HII being overpowered by the new super hot blue stars created by these regions. It also has an active nucleus of the Sy2 class. This is because it is considered a starburst galaxy by many of the papers I looked at.

It has a rather broken bar with arm segments coming off not just at the ends. One arm seems to come right off the core on the east side. Several arm segments come off the west side, one at the core and two below the core. North of the core it's pretty much a jumbled mess on the west side. I saw nothing in the papers about any ideas how it got this odd structure. Could a merger be involved? I have no idea. Seems possible. I'd expect that to show in a detailed velocity analysis of the galaxy. Apparently, that's not been done as best I could tell. Did anything come of the HST image? Again I drew a blank. The Hubble site only talks about how it shows the ACS camera is again operational.

NGC 6217 was discovered by William Herschel on December 12, 1797. It is in the original Herschel 400 observing program. My notes made on May 18, 1985 with my 10" f/5 at up to 120x on a good night reads: "Oval galaxy with a starlike nucleus. No detail is seen in the halo. Arms can be made out but aren't what I'd call distinct." I've pushed the contrast of the arms in my image. See the included SDSS image for a more natural presentation.

Near the left edge of the image is the strange spiral galaxy UGC 10509. Its arm structure is very weird. Is this really two interacting galaxies on top of one another? I don't really see a core of a second galaxy. Did it interact with either or both of the nearby galaxies to the north? Only one has redshift data. That indicates it is likely at least part of the same local group. Neither companion seems distorted, however. Being much smaller I'd expect they'd suffer far more in an interaction. For now, I'll say they likely aren't interacting but something certainly has it would seem. Unfortunately, Hubble didn't test the ACS camera on it.

Only a very few other galaxies are even cataloged in this field. Coverage up by the pole seems rather poor for galaxies. What I did find were several X-ray sources. All are very bright in visual light. Some are very blue which isn't surprising for an X-ray object. The ones with the RIXOS prefix were found by the ROSAT X-ray satellite's survey. All of those are considered by NED to be X-ray galaxies with active galactic nuclei. But not as quasars though they are so bright and so distant I find that surprising. I'd think only a quasar would be that bright at their distance. One is from the RX catalog. Also the result of the ROSAT X-Ray satellite but apparently not from the survey? I am only guessing as to the difference. These, NED says, were obtained not from a published catalog but from "the literature". The one with that designation in my image is listed by another X-ray catalog (Pietsch+Arp) as being a quasar. It is more distant than all but one and by far the brightest in apparent magnitude.

NED also lists 5 galaxy clusters from the OC05 and OC06 galaxy cluster catalogs (Optical Cluster). Unfortunately, the positions are listed with an error circle of 25" of arc radius! Also, no size or galaxy count is given. Because of there being no way to pin down their location to a sufficient degree and lack of any other data I didn't include them in the annotated image For those interested enough to look them up they are: OC06 J1633+7808; OC05 J1632+7806; OC04 J1629+7811; OC04b J1629+7806 and OC04a J1629+7803.

Most galaxies in the image weren't cataloged any place I looked. Even the rather bright blue fuzz ball southeast of Arp 185. I marked it with a question mark. I really am interested in what the heck it is. Most galaxies of its shape are ellipticals that are very red. It probably is an S0 galaxy seen end on. Usually, they have a higher surface brightness than this one does. It's likely a rare breed, whatever it is.

Arp's image:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp185.jpeg

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

Related Designations for ARP185

ARP186

Arp 186/NGC 1614 is one of the few highly studied galaxies in Arp's catalog. Oddly, the majority of his galaxies have received little attention. This one has been studied extensively at IR and radio frequencies as well as optical by the Hubble Space Telescope. It is thought to be the merger of two galaxies that is nearly complete. The tidal tails are still evident so the merger is very recent. The Hubble web page on this one tells its story so I'll refer you to that link for the details. http://hubblesite.org/image/2302/news_release/2008-16

Arp classed it under Galaxies (not classifiable as S or E): Narrow filaments. It is located in Eridanus and is about 200 million light-years away. It was discovered by Lewis Swift on December 29, 1885.

Besides the ordinary full image at 1" per pixel I've included a 2x enlargement of just the galaxy rotated to closely match the Hubble image so that west is at the top rather than north as the full image is oriented.

The near edge on like galaxy south of Arp 186 is 2MFGC 03719. I find no distance estimate for it. There are two blue galaxies to the southwest of Arp 186. The one nearest to Arp 186 is PGC 146387 about 475 million light-years away, or over twice as far as Arp 186. The other one is 2MASX J04342393-0839138 also at about 475 million light years so those two are near each other. The gray galaxy above and a bit left of Arp 186 is PGC 1003489.

Hubble image
http://www.spacetelescope.org/images/heic0810ax/

Arp's image
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp186.jpeg

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

Related Designations for ARP186

ARP187

Arp 187 is classed under Arp's Galaxies (not classifiable as S or E): Narrow filaments. It is otherwise known as MCG-02-13-040A, a radio galaxy about 550 million light-years away.

Arp's image, inverted from mine, shows a faint narrow filament going southeast from the galaxy. It is best seen in my image if the image size is reduced. On the other hand, I show a large filament to the NW out of the frame of Arp's image. It shows on the DSS plates so is real though only slightly above my noise level. I do need to add time to this one. Arp apparently saw the NW filament as shown by his comment: "Faint filament points to dense nucleus. Possible fainter filament toward compact galaxy to NW." The galaxy is located in the northeast corner of Eridanus not far from Rigel. This is likely a somewhat obscured region due to dust in our galaxy. It's also too far south for good seeing from my location.

This field is rather barren of other galaxies. Nor do I see a certain candidate for interaction with Arp 187. It might be that it is the result of a merger that has already happened. The northern filament passes right by a possible candidate. It's just right of the filament and appears like a slightly distorted star. It is the IR galaxy 2MASX J05045039-1013535. Little information is available for it. One note at NED says; "Interacting with compact galaxy to the northwest? Radio-source. M 05-10, 6 arcmin to the north." Is this the galaxy the note refers to? I don't see it being massive enough to have caused this much disruption if at the same distance. It appears to me more likely it is far beyond it. As to the radio source, NED doesn't list it or show any source 6 minutes north of Arp 187.

The obvious galaxy west and a tad south of Arp 187 is 2MASX J05044617-1015169, another IR galaxy with little information available.

The large galaxy near the top right of center is IC 401, an SB(rs)b? and possible LINER galaxy about 150 million light years distant. Far too close to have anything to do with Arp 187. There are a few other IR galaxies in the image but none with much information. It was discovered by Stephane Javelle on February 9, 1893.

Arp's image:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp187.jpeg

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

Related Designations for ARP187

ARP188

Arp 188 is the Tadpole galaxy, PGC 057129/UGC10214 SB(s)c pec. While the image says I used 60 minutes of Luminosity data clouds and lousy transparency limited it to more like 20 under good skies. This made for a very noisy image and I had to do some rather nasty processing to deal with the noise. The lousy light transparency meant I didn't pick up the "tail" all that well. Arp classifies it under "narrow filaments" which obviously refers to the tail which, isn't connected to any of the spiral arms. SIMBAD catalogs it as an interacting pair. It is thought the galaxy that left the long tail is GALEXASC J160601.81+552524.2. I've noted it on the cropped annotated image. It appears little is left but a disrupted core after it created the long tail.

I wanted to find the distance to the little edge-on to its right but had a major surprise. While both NED and SIMBAD list OVER 5700!!! galaxies within 5 minutes of the Tadpole (usually the count is 5 to 10 if the area is really crowded) but the one I wanted to know about was not one of them! In fact, the only galaxy in the area I could find that's in my photo is the golden round elliptical to the southwest (about 5 O'clock) just above a bright blue star. It is at the same distance as the tadpole. So what about those 5700+ other galaxies. All are dimmer than 24th magnitude, thus far below my limit and were taken from Hubble's images of this galaxy.

But there's something even more interesting in this photo. When I download the first frame of a new field I always compare it to the Palomar Digital Sky Survey plates. Since my images usually go deeper than these plates it is common to find faint stars not on the survey but this time I came up with a rather "bright" one. It's the star above and right of the nucleus. It is 6.2" north and 7.2" of arc west of the core of the tadpole. Had I found a Supernova? Yes, it was a super nova but it had been discovered 3 days earlier by the Lick Super Nova Search. It missed me by 3 days to paraphrase Maxwell Smart. Close but no cigar. It is SN 2008dq a type 1-C supernova. These are a core collapse type involving an old massive star that has run out of anything to fuse. A 1-C type has thrown off most of its helium layer prior to the collapse.

This galaxy also had a SN last year SN 2007cu. Two in one galaxy only one year apart is very rare. The one in 2007 was a white dwarf orbiting a normal star very closely. Such a supernova pulls matter from the ordinary star until it reaches the mass needed to reach its detonation point and blows up. Such stars are usually older than those that form a 1c type of super nova. So they are likely unrelated and their closeness in time only a coincidence.

The Tadpole and the elliptical I mentioned are a bit over 400 million light years from us.

Arp's image: http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp188.jpeg

14" LX200R @ f/10, L=6x10' RGB=2x10'x3, STL-11000XM, Paramount ME

Related Designations for ARP188

ARP189

Arp 189/NGC 4651, the Umbrella Galaxy, is a member of the Virgo Cluster of galaxies in the constellation of Coma Berenices. As such it is about 60 million light-years distant. So I'm a bit perplexed with its coverage by NASA's Astronomical Picture of the Day entry for it. They say it is 35 million light-years distant. Its redshift distance is about 51 million light-years while NED lists many distance measurements by Tully-Fisher averaging about 85 million light-years and a Sosies measurement of 77 million light-years. Nothing that I found agrees to APOD's 35 million light-year distance. In other words, does anyone really know its distance?

Arp put it in his category of galaxies with narrow filaments. His comment reads: "Radio source near tail apparently not associated." We now know that its odd structure is due to it eating another galaxy in the recent past. The "narrow filament" is the remains of the galaxy showing its path around the galaxy as it was torn apart by gravitational tidal forces. NGC 4651 was discovered by William Herschel on December 30, 1783. I was somewhat surprised to find it isn't in either of the Herschel 400 observing programs.

I prepared an annotated image as there were some very distant galaxies on the east side of Arp 189. Probably on the other sides as well but for some reason, the Sloan survey only took redshift data mostly in a very small area of my image. All of it on very distant galaxies and one quasar. The quasar is closer than many of the galaxies! While my image is poor in focus it did go deep anyway with galaxies down to 23rd magnitude recorded. You may need to blow up the image to find some of these very faint ones. When you do you will find the field jammed with tiny faint fuzzy spots. I had thought this just background noise but when I looked up the position of these 22nd magnitude and fainter galaxies at 5 and even 6 billion light-years there was one of these fuzzy blobs dead on the position. Most agreed to a few hundredths of a second of arc. If off by more than the error circle of the SDSS data I skipped it. Only happened once. In one 10" circle that I tested there were 5 and every one had an entry in the catalog though only 1 had redshift data. Thus, I'm quite sure these faint blobs (blow up the image 3x or more to see them) are distant galaxies.

One galaxy with redshift data and out of the concentrated area is LEDA 140003 in the lower left corner. NED gives it two entries with no indication that they are duplicates. Both are listed in the 18th magnitude range with positions less than 1 second of arc (less than one pixel) different. The redshifts were slightly different as well. I've listed both on the annotated image. There does appear to be a second bright area that is below the core by three seconds of arc, far more than the separation NED shows and in the wrong direction. Both are listed with a position error circle of 1.25" of arc, more than the difference. But this doesn't explain the difference in the radial velocity measurement.

I've listed a few of the brighter galaxies that had no redshift data by catalog name. This is followed by a question mark as the distances are completely unknown.

Arp's image:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp189.jpeg

APOD image deeper than any of the above or mine with overlay of the path of the doomed satellite galaxy:
http://apod.nasa.gov/apod/ap100415.html

14" LX200R @ f/10, L=16x10' RB=6x10' G=5x10', STL-11000XM, Paramount ME

Related Designations for ARP189