ARP307

ARP 307 falls under his class: Group Character: Group of Galaxies. It is located in Leo with has more than its share of galaxy groups. Arp's comment: "Possibly not interacting." It consists of three galaxies, NGC 2872, NGC 2873 and NGC 2874. Not exactly right to left. NGC 2872 is the big E2 elliptical. Redshift data puts it at about 160 million light years distant. NGC 2873 is also about 160 million light-years distant by redshift. NED doesn't give a Classification. The NGC Project says Sb which seems reasonable. It certainly is a red spiral, a new class of galaxy to come out of the Galaxy Zoo project. This leaves the big barred spiral, NGC 2874, also a red spiral or maybe a normal spiral in the process of turning red as most new star formation has apparently long ceased with the massive blue stars long dead but some slightly blue ones left in a few knots. Classed at NED as SB(r)bc and questionably (to me) as Sc by the NGC Project. It seems a very obvious barred spiral. Though the Hubble Space Telescope image makes the bar less obvious. Redshift data puts it at 180 million light years distant. This could be due to random motions in the group or could really mean it is unrelated. I lean toward it being part of the group as there appears to be a hint of interaction at the southwest end.

There are two other nearby NGC objects. NGC 2871 is just a blue star at the north end of NGC 2872. This type error is rather common in the NGC. Things get a bit more interesting with NGC 2875. I find two positions and two identities suggested for it. Both are shown in the annotated image. There's no question this object is in the northeastern part of NGC 2874. NED's description and position point right to knots in the northeastern arm. The NGC project, however, points to an area just above two apparent stars where the galaxy is rather dim. But gives almost exactly the same position as NED. Then says "This is the north-following part of NGC 2874. Lord Rosse's micrometrically measured offsets point exactly at the rather knotty spiral arm, and his description is consistent with the appearance on the Sky Survey (DSS 1)." This seems to describe the arm NED points to but their diagram points where I show it in the annotated image. Most likely their diagram is wrong.

NGC 2872 and 3874 were discovered by William Herschel on March 15, 1784. They didn't make either H400 observing program. NGC 3873 was found by R. J. Mitchell on February 22, 1857. Lawrence Parsons is responsible for NGC 2875 on March 7, 1874.

A couple notes about the annotated image. Two faint galaxy clusters are anchored by a cD galaxy. These are noted by G/CG with the distance shown being that of the cD galaxy. At bottom center, there's an object that NED lists in some catalogs as a galaxy with an AGN and others call a Quasar. It is marked G/Q for that reason. Labels are immediately west of the object unless that would cover up some other object. In those cases, a line points to the object.

There are 5 asteroids in the image. They are labeled in the annotated image. Here's the list in order of closest to furthest from the center of the image. Magnitudes are estimates of the Minor Planet Center. These aren't always very accurate. Note that Burkam is listed as at more than a magnitude brighter than the rest but appears dimmer than the brightest. Some of this may be due to the lack of red sensitivity in my sensor.

(155041) 2005 QZ172 19.8
(158647) 2003 DL2 18.7
(14570) Burkam 17.3
(97481) 2000 CF61 18.2
(121727) 1999 XQ155 18.7

Naming citation for Burkam:
"Ann Burkam mentored a finalist in the 2002 Discovery Channel Youth Science Challenge (DCYSC), a middle school science competition. She teaches at the Buckeye Valley Middle School, Delaware, Ohio."

When taking this object the first blue frame was dimmed by clouds. The following night I took two more blue frames. I seemed to get better color including the first blue than I did not using it so this is why there are 3 blue frames and only 2 of the other colors.

Arp's image:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp307.jpeg

Sloan image:
http://astronomerica.awardspace.com/SDSS-19/NGC2872-4.php

Black and white HST image
http://upload.wikimedia.org/wikipedia/commons/c/cf/ARP307-NGC2872-NGC2874-HST-702.jpg

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

Related Designations for ARP307

ARP308

Arp 308 is a pair of galaxies; NGC 545 and NGC 547 that is associated with the radio source 3C40. That is NGC 547 is considered to be the source of 3C40. Arp put the pair in his category of simply double galaxies. His simple remark says: "Close ellipticals." which isn't very informative. NGC 545 to the north is listed as an SA0 galaxy while NGC 547 is E1 and a bright cluster galaxy. Redshift puts it at 6 million light-years further from us that NGC 545. However, NED gives a D-Sigma distance determination that is the same for both. Likely the difference in radial velocity is due to relative motion rather than distance. The exact same D-Sigma distance is found for NGC 541 (Arp 133) as well. A 1964 paper concludes NGC 545 is not interacting with NGC 547. I find that hard to accept.

Notes about the annotated image.
Objects considered part of Abell 194 are listed by name.

Redshift distance using NED's 5 year WMAP assumptions are used. They are expressed in billions of light-years. Differences in cluster member radial velocity are most likely due to relative velocity around the cluster's center of mass rather than a true distance indicator. Most, likely lie within a few million light-years of each other. The label is immediately right of the object when possible. Otherwise, a line will connect the object and its label.

XMMU J012535.9-012546 is an X-ray galaxy. It appears to be a very compact dwarf of some sort.

ARK 45: A note at NED says "Together with NGC 0547 this is the radio source 3C 40." I'm not sure how this was determined, especially since NGC 545 is in the middle yet not considered part of 3C 40 that I found. Also, note its redshift is surprisingly different.

NSCS J012537-011739 is a galaxy cluster at 4.97 billion light-years. It contains 36 members. The diameter isn't specified. I see a dozen or two within a few minutes of the center. Many look like faint stars.

WHL J012538.1-011301 is another galaxy cluster at 5.3 billion light-years. It contains only 8 members. Its center is a couple seconds of arc from a faint galaxy, probably the anchoring member. The NED position is only approximate so likely means to point to this galaxy.

The UvES (Ultraviolet Excess Source) is likely a quasar given its distance.

Arp's image of these galaxies is made from the same plate and cropped to exclude the other atlas entry. Most of his images are shorter than the one hour exposure on 103a-0 image. The added time is likely due to losses in the "Polaroid" filter. He lists the seeing as average 1" to 1.5".

NGC 535 and 543 were discovered by Heinrich d'Arrest on October 31, 1864.
NGC 541 was discovered by Heinrich d'Arrest on October 30, 1864.
NGC 545 and 547 were discovered by William Herschel on October 1, 1785. It isn't in either Herschel 400 observing program.
NGC 548 was discovered by George Searle on November 2, 1867.

Arp's image of Arp 308
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp308.jpeg

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

Related Designations for ARP308

ARP309

ARP 309 is made up of two interacting galaxies, NGC 942 (lower) and NGC 943 (upper). The pair is located in Cetus about 200 million light-years distant. They are the largest two of a group of galaxies known as the USGC S088 group. NED lists it as having 8 members. While they are not identified there are 8 galaxies with known redshift values which indicate they are at the same distance as Arp 309. Since no other galaxies in my field have redshift values I've not labeled any but those probably in the group.

Arp put #309 in his class for double galaxies. Arp apparently missed or wasn't interested in the large plume going north from NGC 943 or the smaller one going south from NGC 942. His only comment addresses the very red dust ring in NGC 943 when he says: "Peculiar absorption ring, possibly broken." Both were discovered by Frank Muller sometime in 1886. The exact date is unknown.

Arp's image
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp309.jpeg

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

Rick

Related Designations for ARP309

ARP310

ARP 310 and 311 is an odd combination in Arp's catalog. Arp 310 consists of IC 1259, a close pair of galaxies. Arp 311 consists of Arp 310 and adds IC 1258 to its southwest and IC 1260 to its southeast. Arp 310 is classed under Group Character: Galaxy pairs while 311 is under Group Character: Galaxy Groups. There are other galaxies in the area but as far as I can determine they aren't included in 311 by Arp. Arp 311 is also known as WBL 640 and is listed by NED as consisting of only 4 galaxies. But the SDSS lists a cluster centered on Arp 310 called SDSS-C4-DR3 3143 consisting of 47 members. It puts the average redshift for the group at 8394 km/s while that of Arp 310 is a bit less at 8100 km/s. The difference is insignificant as relative motion within a cluster can easily exceed this difference. So apparently the group is much larger than Arp realized. Using this latter redshift the distance to Arp 310-311 would be about 375 million light-years. Arp's comment on Arp 310 was simple that it consisted of two close elliptical galaxies. He had nothing to say about Arp 311. These galaxies are located near the head of Draco, just east of the Draco Dwarf Galaxy, a satellite galaxy of our Milky Way Galaxy that is one of the dimmest galaxies known consisting mostly of "dark matter" and a handful of stars.

Arp 310's two galaxies are classed as S? (right) and S0 pec (left) by NED. This disagrees with Arp's elliptical statement but does agree with my image that shows them as having a somewhat bluer cores than the outer halo. Most ellipticals have a far redder core than these do. IC 1258 is classed by NED as Sab? I'd put a pec on that. It does appear to have somewhat blue arms but this is an illusion. Looking at the three color planes red is slightly stronger than blue yet it appears blue to my eye when compared to the red of the nearby galaxies and its own core. My image seems to show a bridge of red stars between the two galaxies. As best as I can tell Arp usually used a blue sensitive film with a yellow filter to take most of his images. This won't pick up a bridge of red stars very well but I think I see a hint of it in his image when shrunk down. Odd he never commented on it.

There's a lot going on in the image. I've prepared an annotated image. Galaxies in the SDSS-C4-DR3 3142 cluster beside those of Arp 310 are listed by name with no distance while those far beyond the cluster are listed by distance. Quasars are also listed by distance. One is very near Arp 310. Something Arp considered meaningful rather than a coincidence nearly all other astronomers agree it is.

In the annotated image note the two very close quasars in the lower right corner, both of which have virtually the same redshift showing a distance of 8.7 light-years. The redshift of the one on the left is z=1.269000 while the left is z=1.269040. I find nothing to indicate they are the product of gravitational lensing. Their colors are not the same, the left one has far more blue in it. Two quasars this close, 7 seconds of arc, is rather unusual I'd think. I'm only guessing here.

Arp's images:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp310.jpeg
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp311.jpeg

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

Related Designations for ARP310

ARP312

ARP 312/HOLM 758 is a group of galaxies in northern Hercules located about 525 million light-years away. It falls under Arp's category Group Character: Groups of Galaxies. There are several Arp galaxies in this area northeast of M92. While the galaxies of Arp 312 have about the color of elliptical galaxies they are a bit bluer than most leading me to wonder if these were spirals and have interacted sufficiently to eject their dust and gas so are turning into elliptical galaxies. I find very little on this group so this is pure speculation on my part.

How many of the galaxies Arp considered to be in the group is also a bit difficult to determine. NED seems to list only 2, the two northern ones sharing a common halo of stars. Webb and Kanipe include the bright galaxy to the southwest. Arp included the one to the northeast by a star in his photo. His comment reads; "Diffuse connection between central members of the group." Obviously, the two brighter members show a common halo. Look closely and it extends to the southwestern one as well. That would be 3 members, not just "central" ones. So is Arp referring only to the two with the obvious halo and considering the northeast and southwestern ones members not sharing a "diffuse connection?"

The three major galaxies are: MCG+8-31-4, the southeastern one; MCG+8-31-5, the largest of the group; and MCG+8-31-6 the easternmost galaxy of the three. The one hiding behind the star to the northeast is 2MASX J16495421+4643284 a strong IR emitting galaxy. But that applies to the other three as well as they too are in the 2MASX catalog which was conducted at the 2 micron IR/microwave wavelength. I find redshift data only on MCG+8-31-5. I'd assume the three in the MCG catalog are all about the same distance due to the common halo. Most everything else in the area is a mystery, unfortunately. No one seems to even be trying to classify any of the 4.

While this area has been surveyed by the Sloan project no redshift data for the entire field was found in NED. There are lots of interesting galaxies but while I can put names on them that is about all I can do so I haven't bothered to prepare an annotated version. The bright star is a 7th magnitude K2 star that gave me fits when processing this image.

Sloan image:
http://astronomerica.awardspace.com/SDSS-12/MCG8-31-4.php
Their image really shows what a pain that K2 star was!

Arp's image:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp312.jpeg

Besides the normal full image I've attached a cropped version at 0.5" per pixel, twice my normal resolution.

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

Related Designations for ARP312

ARP313

ARP 313 is a trio of interacting galaxies. The biggest member in the center is NGC 3995, to the west (right is NGC 3994. The glow-worm like the galaxy to the northwest (upper right) is NGC 3991. Redshift data shows these to be about 150 to 157 million light years from us. NGC 3994, the undistorted one having a redshift that could indicate that it is a good 5 million light years closer thus explaining why it shows so much less distortion. Still, it is a LINER galaxy which indicates something is going on. LINER stands for Low Ionization Nuclear Emission Region. A very complicated way of saying that the core of the galaxy has emission lines indicating there's a lot of gas in the core that is slightly ionized -- that is not many of the electrons are missing but more than you'd expect. The cores of most galaxies are pretty dust and gas free. That is out in the disk of the galaxy where we live. But in galaxies that have interacted with others or that have really active cores due to a hungry black hole, it is seen. Since NGC 3994 doesn't seem to have an active black hole the LINER status would indicate it is feeling the interaction with the other two. Also if you look closely you can see some tidal arms coming off the north and south ends of it. Unfortunately, again taken in moonlight, I can only bring out a hint of this without making the image very noisy. I've attached a crude stretch to show this halo. It appears to connect to NGC 3995 but that is mostly noise from the moon and not real. I need a moon free night to tell more.

NGC 3995 and NGC 3991 are certainly interacting as shown by the very weird nature of both as well as the very blue colors in both indicating massive new stars have formed in these galaxies in the last few million years. Considering the galaxies are at least 10 billion years old this is very young astronomically speaking.

NGC 3991 and 3995 were discovered by Heinrich d'Arrest on February 5, 1864 while he found NGC 3994 on April 6, 1864.

Arp's image: http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp313.jpeg

14" LX200$ @ f/10 L=4x10' RGB=2x10'x3, STL-11000XM, Paramount ME

Related Designations for ARP313

ARP314

Late last summer I started to have problems with elongated stars. I had to throw out frames and retake them to eliminate this. I couldn't track down the problem. This is probably the most affected image. Retaking didn't help, I just had more elongated stars. I was getting desperate. I decided to regrease the gears and see if that helped. I also had a bad USB cable that needed replacing. These route through the axes. I opened the Dec axis' compartment to pull out the bad cable and found it totally packed with sunflower seeds some little critter (mouse or vole most likely) had stashed there. Once the seeds were removed my oval stars went away. I plugged the openings around the cables with steel wool and set traps. Traps didn't trip or have bait eaten so I assume the critter had already met up with one of the owls that hang around here, great horned and barred. I never retook it. The tracking problems were quick so only distorted brighter objects. Galaxies seem to have been immune to the quick excursions caused by the seeds. Even tiny star forming regions in the "shock wave" like features of the two highly distorted galaxies are well resolved.

Arp 314 is classed by Arp under groups of galaxies. Most sources say it is a three galaxy group leaving off the one to the southeast that appears to be creating some sort of shock front full of star forming regions. Arp did include it in his photo and mentions it in his comment saying "Faint filament leads SE to faint dwarf." So I think he was including it yet most catalogs don't include it. Maybe that's because there's no redshift data so it's possible it is at a very different distance. Possible but doubtful what with its odd distortion and that arm leading toward it. Or maybe he was referring to the condensation at the end of the filament. It isn't cataloged anyplace I could find as a separate object but maybe that is what he means.

Arp 314 is in the constellation of Aquarius just west of Arp 223 under the Circlet of Pisces. It is about 150 million light-years distant, only about 8 million light years more distant than nearby Arp 223. Since orbital velocities in galaxy groups can easily cause even greater redshift differences it's quite likely these are part of the same galaxy "local group."

The northern galaxy is MCG -01-58-009 and is classed as (R')SA(s)bc? pec. The galaxy with the tidal arm is MCG -01-58-010 classed as SB(rs)cd: pec. The third member all agree on is the odd elongated one to the south of MCG -01-58-010. It is MCG -01-58-011 classed as (R')SB(s)dm pec. The fourth galaxy that NED and others don't consider part of Arp 314 for some reason is basically anonymous. It has only been cataloged by aN automatic plate measuring survey with the UK Schmidt camera as APMUKS(BJ) B225548.75-040459.3. The extended PGC lists it as PGC1066529. It lists a magnitude of 17.1 while the APMUKS listing shows it as 16.3. That's quite a difference but could but due to the color this was measured in. It hasn't been classified nor studied that I can find yet seems to be a very interesting galaxy. What is causing that odd arc of new stars "in front" of it? MCG -01-58-011 seems to have a similar arc of new star forming regions to its west as well. MCG -01-58-009 is the only one that only looks sort of messed up. At least its spiral structure is somewhat in tact. That's certainly not the case with the 3 others.

There's a cute little comma of 5 galaxies in the upper left corner just right of a fairly bright star. Two are in the APMUKS catalog, all are otherwise anonymous. Four are about the same brightness. Are they a small group? Brightest is about 20th magnitude.

The obvious asteroid in the upper right corner is (12324) Van Rompaey at magnitude 16.8. Much harder to see toward the lower right corner is 2005 QC1 at magnitude 19.3

Arp's image
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp314.jpeg

Hubble hasn't seen fit to explore this system.

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

Related Designations for ARP314

ARP315

Arp 315/Abell 779 is a group of galaxies in southern Lynx. Arp 315 is just 3 of the 83 galaxies in the Abell 779 galaxy cluster that mark the heart and is likely the anchor of the group. Arp put them in his Group of Galaxies category. The three in his atlas are NGC 2830, NGC 2831 and NGC 2832 right to left. They don't appear to be interacting so are likely further apart than our perspective makes it appear. His comment reads: "Companion E [NGC 2831] is quite compact."

The group is about 300 million light-years from us. NGC 2832 dominates the group. It is obviously a cD galaxy ("central Dominant), also under Yerkes galaxy classification, it means by the c that it is a super giant galaxy and the D that it is diffuse (elliptical), galaxy. NED classes it as E2+2 while the NGC project says E4. NGC 2831 is classed as E0 by both. NGC 2830 is simply S under the NGC Project and SB0/a: per NED. It appears to be nearly edge on.

NGC 2825 was discovered on April 3, 1831 by John Herschel
NGC 2826, 2831 and 2832 were discovered on March 13, 1850 by George Stoney
NGC 2830 was discovered by William Herschel on December 7, 1875 but isn't in either H400 program

I've prepared an annotated image that shows both the catalog entry and redshift distance per NED using 5 year WMAP data. There is quite a spread likely indicating rather high orbital velocities of the galaxies in the group. Including the identification rather than just the distance greatly increased the file size as well as making it hard to put in labels without overwriting other objects. If the object isn't a member of the group I only show its nature (Q-quasar, G-galaxy) and distance. Those without a label had no distance data in NED so I couldn't determine if it was a cluster member or not. A few weren't in NED's database. I noted one of these, a rather bright one, with a question mark. Why these don't make the catalog is still a mystery to me. No one seems to know the answer, at least no one has told me.

Looking around the image there are a lot of galaxy pairs and triples, many of which appear to be interacting others just line of sight pairs. There's a lot going on all over this image if you go looking for it.

There's one asteroid in the image, (230947) 2004 XY54 at magnitude 18.5

Arp's image
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp315.jpeg

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

Related Designations for ARP315

ARP316

I was going through all my Arp images trying to get them organized. I found some of my very early ones, back when I was just taking interesting galaxies and paying no attention to the Arp catalog, were very poorly processed. This one is one of them. Arp 316 consists of 3 galaxies NGC 3187, NGC 3190 and NGC 3193 and is located between two stars of the sickle of Leo. NGC 3185 is part of the Hickson 44 group but apparently not part of Arp 316. Arp classifies it under "Group Character: Groups of galaxies. A redundant classification. Reminds me of when I was in college working for an accounting firm. Bookkeeping was done by IBM punch cards on a mechanical rather than computer system. The firm with the equipment forced all users to the same expense categories. There were 9 possible classifications in three levels defined by the numbers 1-9. Each refined the previous category. 9 was Other, 9 under that was Miscellaneous and 9 under that was Misc. I was told that I could never use account 999 for obvious reasons. So they did Arp one better with redundant classes.

The main galaxies of the group include NGC 3185 at the bottom (not part of Arp 316). It is classed as SB(r)a and is thought to be about 70 million light-years away.

NGC 3187 is the wide armed spiral, SBc pec, and is thought to be about 85 million light-years away. Note how the upper arm has lots of fine detail but the bottom one looks all "windswept" and fuzzy. Must have happened in the tidal interaction that gave it such wide spread arms in the first place though I can't recall seeing this effect before. Notes indicate it is interacting with NGC 3190 and maybe NGC 3185.

The big spiral in the center with the very weird dust lanes is NGC 3189 (lower part) and NGC 3190, rest of it. Most sources just use the NGC 3190 designation, however. It is classed as Sa pec LINER and is thought to be 73 million light-years away. Note the two planes to its dust lanes. There's the main lane which at the NW end suddenly seems to separate and go off at a different angle for a short ways. Then toward the other end, it splits with a fine lane resuming about the same plane as the odd piece at the other end. But they don't point at each other, just that they seem to be at about the same angle in relation to the main band. Very odd. Lots of tidal spray around the galaxy as well. This may be the result of a merger that hasn't yet been pulled into one plane.

The upper galaxy is NGC 3193 E2 LINER and has a redshift distance of 79 million light-years but there are indications it is really about 96 million light-years away.

This group is also known as Hickson 44. NGC 3185 and 3187 were discovered by George Stoney in January 1850. Sorry I couldn't find a more precise date. The other two NGC 3190 and 3193 were discovered by William Herschel on March 12, 1784. I find it odd he didn't find the first two as they are seen in my 10" f/5 scope though 3187 is more difficult than the other three. Both of Herschel's galaxies are in the original H400 program. My notes from April 15, 1985 under humid but fair skies at up to 150x reads: "3190: Oval galaxy, gradually brighter toward the center. This galaxy is not a winner except when you take the other three into account. Does form a nice high power pair with NGC 3193. 3193: Small, not quite circular galaxy near a field star. Forms a high power pair with 3190. It has a large bright core with a tight halo about it." It appears this group is photographically much better than seen visually, at least through the humidity I was dealing with that night.

The blue spiral toward the SE corner is LSBC D500-05 an Sc spiral, LSBC stands for Low Surface Brightness Catalog. The galaxy is listed with a redshift that puts it about 200 million light-years away. Thus it must be a rather large galaxy.

Blue galaxy well west of NGC 3190, halfway to the edge of the image is LEDA 086788 an Sc galaxy at about 100 million light years which puts it at least in the vicinity of Arp 316.

The tiny SO like galaxy between NGC 3190 and NGC 3193 is SDSS J101811.88+215130.0. I find no info on it other than the note "candidate dwarf".

The much larger fuzz blob to the southeast of NGC 3193 is SDSS J101833.31+215138.2. There's little on it, however.

Most of the other blue fuzzies aren't even listed in NED which surprises me as this is an area covered by the SDSS yet they aren't in it either.

ARP 316 as a whole is listed by NED at a distance of 78 million light years by redshift.

This was taken on a night of better than normal seeing. So I was able to get a lot of detail in these galaxies. But what really strikes me about the image is that the spread of faint objects is very uneven. There's an area around the 3 upper galaxies and one bright star that has a lot of faint objects in it. But the rest of the image has far less. You normally don't think of dust in Leo but it seems like something could be reducing the background except in that one area. It appears most of the objects in this "enhanced" area are galaxies. I searched NED for some galaxy clusters in the area and came up with two but they are centered near NGC 3187 or a bit above it. Still, they show a distance of over 2 billion light years which does seem to fit. They are NSC J101747+215255 and 400d J1018+2154. They are likely seeing the same group. There's not much data on either as to size density or galaxy count.

Arp's image of the group taken this time with the 48" Schmidt telescope due to the area being too great for the 200" field of view, is at:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp316.jpeg

The SDSS image:
http://astronomerica.awardspace.com/SDSS-21/NGC3193-90-87.php

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

Related Designations for ARP316

ARP317

Arp 317 is also known as the Leo Triplet. It consists of three galaxies, NGC 3628, M65 and M66. M66 by itself is also Arp 16. Unfortunately, my field of view is too small to include all three even in a mosaic of two images as the distance between the two Messier objects and NGC 3628 is just too great. For a view that shows all three in one image see: http://cseligman.com/text/atlas/ngc3628wide.jpg

While many sources consider all three galaxies to be interacting Arp's comment only dealt with two, M66 and NGC 3628 when he wrote: "Both galaxies on east show signs of interaction." M66 has large plumes as well as some large H alpha regions I picked up even without the aid of an H alpha filter. NGC 3628 is rather famous for a long streamer of stars coming off its northeast end heading east. Unfortunately, I took my image of it when I first was getting into digital imaging and had no idea I needed to manage the system noise of my camera. The result was that I lost the streamer due to severe system noise covering it up thanks to my short exposure time. For some reason, I've never gotten around to retaking it. NGC 3628 is often called the Hamburger Galaxy due to its wide, dark dust lane reminding some of a hamburger patty in a bun. I can't say that it works for me but I'm not a big hamburger fan in the first place (sorry McDonald's, Burger King, etc.)

I've included my image of M65 and 66 though you will see that also at Arp 16. I was fortunate enough to catch M65 with a supernova though it was fading when I finally got around to imaging the pair. NGC 3628 has a redshift distance of about 55 million light-years at NED but an average of about 15 non-redshift measurements says it is only about 35 million light-years distant. NED classifies it as SAb pec sp;HII LINER. M65 has a redshift distance of about 53 million light-years but a non-redshift distance of 42 million light-years. It is classified by NED as SAB(rs)a LINER. M66 has a redshift distance of 50 million light-years but a non-redshift distance of 31 million light-years. It is classified as SAB(s)b;LINER Sy2. Even though the non-redshift distances to these three don't agree all that closely compared to the redshift distances most sources put their distances at about 35 million light-years.

NGC 3628 was discovered by William Herschel on April 8, 1784. It is in the original H400 observing program. My comments from the night of April 16, 1985, under fair but humid conditions using my 10" f/5 at up to 100x is pretty bare bones. It reads: "Large, edge on galaxy with a hint of a dust lane. Forms a triple at low power with M65 and M66." How that huge dark dust lane was reduced to a "hint of a dust lane" I don't know. M 65 and M66 were discovered by Charles Messier on March 1, 1780, though many books and articles incorrectly attribute their discovery to Pierre Méchain. You can thank Admiral Smyth for creating this error which was picked up by others over and over again.

Arp's image with the 48" Schmidt telescope:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp317.jpeg

NGC 3628: 14" LX200R @ f/10, L=8x5' RGB=2x10', STL-11000XM, Paramount ME
M65 and 66: 14" LX200R @ f/10, L=4x10 RG=2x10' B=4x10', STL-11000XM, Paramount ME

Related Designations for ARP317