ARP277

Arp 277 is in Arp's category for interacting galaxies. While there are many dozen interacting galaxies in his catalog he has only 6 entries for this category, all NGC galaxies. This pair is NGC 4809 (top) and NGC 4810 (bottom). Both are classed as Im pec and are found in Virgo. Neither shows any organized structure that I can see. Redshift indicates a distance of a bit under 60 light-years while Tully and Tully-Fisher measurements put them a bit over 70 million light-years distant. The redshift distance would make them likely members of the famous Virgo galaxy cluster. The pair was discovered by R. J. Mitchel on April 18, 1855.

At the top of the image is NGC 4799. I moved Arp 277 low and right to get it into the image. It too shows hints of distortion. There seems a hint of a tail going due west from the galaxy. My exposure is too short to show it as more than a hint. The SDSS image seems to show it as well but there's a problem. The galaxy is on two different SDSS images processed slightly differently. The result is the southern frame seems to show the plume while it is not very distinct in the upper frame. So is it just noise or real? I'd hoped this would have been enough exposure to answer this but it wasn't. Still, I think there's some reality to it. I'll need to try again. NGC 7499 has a redshift distance of about 140 million light-years and is classed simply as S or S? and is listed as a Seyfert galaxy. If the redshift is correct it is apparently well beyond the Virgo cluster. Seyfert status gives some validity to it having had an interaction and thus makes the faint hint of a plume possible. It was discovered by William Herschel on April 30, 1786. It isn't in either Herschel 400 observing program.

I've made an annotated version of the image. Toward the right side, I've noted the position of a galaxy cluster with 12 members (NSCS J125416+024611). It has about the same position as listed for the galaxy SDSS J125416.01+024600.0 also shown on the image. The cluster likely lies beyond the galaxy. The position for the galaxy doesn't quite match that of a very large, low surface brightness galaxy. But there is no galaxy shown at NED where the galaxy is located. Nor is there any distance listed. So I show 2 question marks for it, one for the location error and another for no distance. (Edit: I've since determined the galaxy is indeed that very dim tiny near starlike object. The large low surface brightness galaxy is SDSS J125415.87+024545.1) It's listed magnitude of 18.9 is fainter than I'd estimate the galaxy but brighter than anything in the area other than the galaxy. There is a tiny galaxy at the exact position shown. It is far fainter than magnitude 18.9 however. This all seems to be an error in the SDSS or in NED's representation of it. My line goes to that faint galaxy. You will likely need to enlarge the image to even see it as it is lost in the eastern edge of the big galaxy. It's likely a member of the galaxy group and thus 2.8 billion light-years distant. That leaves the identity of the large blue galaxy unknown. I'd put its coordinates at J125415.88 +024545.0 (about 3" west and 13 south of NED's position).

This area seems full of confusion. Also in the immediate area is SDSS J125414.47+024616.7. SDSS lists it as a quasar. But it certainly is fuzzy, not starlike, in my image. A check of the SDSS image also shows it as fuzzy though the core is very compact and bright like a star. It's also in the Veron-Cetty+Veron 2006 edition of A Catalogue of Quasars and Active Nuclei as a Seyfert 1 galaxy. Maybe it is both. I've listed it as Q/G. It is rather close for a quasar at only 2.9 billion light-years. It may be a quasar in a galaxy in the galaxy cluster listed at 2.8 billion light-years.

There are two asteroid trails in the image: (65702) 1992 EK4 at an estimated magnitude of 19.0 the upper right and (45722) 2000 GA56 at an estimated magnitude of 18.5 to the upper left. They are noted on the annotated image.

Arp's image
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp277.jpeg

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

Related Designations for ARP277

ARP278

This is Arp 278 or NGC 7253, a pair of interacting galaxies. They are about 200 million light-years from us. NED, my distance source seems to have a problem here. It lists the distance to each individual one as about 191 to 194 million light years. So take your pick. This image was taken at 0.5" per pixel on a good night rather than my usual 1" per pixel my seeing often limits me to. The asteroid leaving a prominent trail is (307771) 2003 WS42 at magnitude 18. Note the dim spot two-thirds of the way along the trail. This is due to clouds which reduced my transparency for about 10 minutes during the 60 minutes that I collected luminosity data. Down in the lower right corner is UGC 11981, a face on spiral galaxy about 278 million light-years from us. This image was cropped somewhat but not so much as to lose the spiral. NED classifies it as SA(s)c. Also, there are a lot of faint fuzzies in the background.

The pair was discovered by Albert Marth on September 9, 1863 and is located in Pegasus. Both galaxies are almost as large as the Milky Way Galaxy we live in so rather large for spiral galaxies. The upper galaxy is classified by Seligman as SABc? while the lower is Sc?.

Arp's image: http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp278.jpeg

14" LX200R @ f/10, L=2x20'x1 RGB=2x10x2, STL-11000XM, Paramount ME

Related Designations for ARP278

ARP279

ARP 279, NGC 1253 and NGC 1253A is a pair of interacting galaxies in Eridanus that are about 70 to 75 million light-years away. Close by compared to most Arp galaxies. Arp put them in his class, Double Galaxies: Interacting. Arp had no comment about these two. The main galaxy is classed as S(B)c by the NGC Project and SAB(rs)cd by NED. The companion is SB(s)m per NED. How you get a barred spiral out of that mess is beyond me. It does have that curving arm-like feature but I'm not sure what it was before the encounter. Comparing my version of this companion to that in Arp's image I'm surprised how bright a couple star clusters are in my image compared to his. This difference holds in the POSS 1 and 2 plates as well. They seem overly bright in my raw FITS files as well so it isn't processing. Maybe instead of knots, they are variable stars in our galaxy caught with both at maximum. Considering I took the data over an eight day period and they show the same in both I find that unlikely. So, for now, its unexplained. My color data for this one is highly suspect. I need to retake the color due to heavy cloud issues. Some of the blue stars are really red I believe. Trying to adjust I just made a mess of the galaxy so left it as is.

For some reason, this pair reminds me of a big fish or maybe sea turtle chasing a small ray that is slashing its tail trying to get away. The big one is leaving a double wake behind it. In any case, these are both distorted in very unusual ways, even for Arp's catalog. NGC 1253 was discovered by William Herschel on September 20, 1784. Like most Arp galaxies he discovered it isn't in either of the Hershel 400 observing programs. I suppose since the Astronomical League also has an Arp program they didn't want many duplications. Only a guess since their various programs do have duplications.

This field is little studied so not much information on the other galaxies in the image. Only the three biggest galaxies besides the Arp 279 pair have any redshift data. They are KUG 0311-031 near the bottom edge a bit west of Arp 279. It is in both the ultraviolet galaxy catalog (KUG) and the IR catalog (2MASX J03134761-0256056) so is both a strong UV and IR emitting galaxy. One NED note says it is "leaf shaped". I don't see that in my image. NED shows a redshift that puts it about 273 million light-years away.

The other two galaxies are along the western edge. The lower is 2MASX J03131021-0254121 at 274 million light years, thus a neighbor of KUG 0311-031. Well, above it is 2MASX J03130881-024319 an S0 galaxy about 375 million light years distant. The brighter background galaxies are mostly listed only in the APMUKS catalog which is just an automated plate survey of objects in the UK Schmidt telescope in Australia. A few are from the 2MASS survey of IR galaxies. Most are not in any catalog I could find.

Three satellites/space debris cross the image. Two are sun glints with faint trails and angle down and to the right. The brighter one goes nearly horizontally across the upper part of the image. I didn't remove them for some reason.

Arp's image
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp279.jpeg

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

Related Designations for ARP279

ARP280

Arp 280/NGC 3769 is a pair of probably interacting galaxies in Ursa Major at a distance of 50 million light-years most say. Redshift puts it a bit closer at 44. It is a member of the Ursa Major Cloud of galaxies which are thought to range about 50 to 55 million light-years distant and includes M108 and M109 as its most famous members. Arp put it in his class of interacting double galaxies. It was discovered by William Herschel on February 5, 1788. It isn't in either Herschel 400 program though is within easy reach of an 8" telescope from dark skies at a visual magnitude of 11.7.

Note the knot in the western end of the major member. Everything I saw on this pair refers to it as a knot, including the Kanipe-Webb book on the Arp Atlas. But in my color image, it came out with an orange core and blue outer parts as if it were a separate galaxy. Knots are almost always blue. If red then its H alpha red due to large clouds of ionized hydrogen in them. This got me searching further. I found a Hubble image (attached) that shows it clearly is a separate barred spiral galaxy. NED doesn't include it either as part of a galaxy or as a separate galaxy. Is it a distant galaxy or a dwarf spiral being digested by Arp 280? Its arms are distorted but I still think it more likely a background galaxy. It wouldn't take much to change my mind, however.

The western member is by far the larger and is classed as SB(r)b:. The NGC project has it as Sb. Considering it appears to have an obvious bar I am a bit puzzled by the NGC project's classification. The eastern member is classed SBm Pec by NED. Looks more like a blob with a few knots to me. The eastern blue blob (a pair actually) carries its own designation PGC036008 Its redshift puts it at 44 million light-years. The same as NGC 3769. So they are a true pair.

In the southwest corner of the image is the galaxy cluster MaxBCG J174.22470+47.81605 at 3.1 billion light-years with 32 members. The diameter isn't listed, however. Is the red galaxy at 3.1 billion Light-years that is well east (left) of Arp 280 a member? If so it is pretty large.

The large galaxy west of this cluster at a distance of about 470 million light-years is UGC 06576, an SB0 galaxy with a very large faint outer disk. It appears to have a small companion to its southwest at about the same distance.

A couple very blue quasars are in the image. In processing it I couldn't help but notice a super blue starlike object east of Arp 280. I was sure it would be a quasar when I went to look it up but nope. It is listed as a white dwarf and X-ray source in the ROSAT catalog All-Sky Survey Bright Source Catalog of X-ray sources, 1RXS J113836.9+475459. That's one hot white dwarf. So where is its planetary nebula? Has it already dissipated? It is labeled as WD/X in the annotated image.

After writing this I found limited data on the western part of this galaxy pair at the Hubble Legacy site. I did a quick enhancement of the mono data there. It supports the idea the blob at the north end of NGC 3769 is indeed a separate galaxy.

Arp's image
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp280.jpeg

14" LX200R @ f/10, L=4x10' RGB=2X10'X3, STL-11000XM, Paramount ME

Related Designations for ARP280

ARP281

ARP 281/NGC 4631-4627 is the first of 6 entries under his category for infall and attraction. The two NGC galaxies that make up Arp 281 are in the process of merging and are gravitationally bound. Nearby NGC 4656 is also gravitationally bound to this system and likely interacted with it hundreds of million years ago by most accounts. The system is likely about 25 million light-years distant though I found no good consensus on its distance. Redshift, unreliable this close, says 40 million light-years. Tip of the red branch estimates at NED showS a distance of about 25 million light-years while Tully fisher measurements show a closer distance of about 16 million light-years. Some papers say 30 million. Non-redshift measurements of NGC 4627 gives a distance of 30 million light-years compared to 19 million for all for NGC 4631. Balancing these and others I decided on 25 million light-years which give a size of NGC 4631 of about 116,0000 light-years. Some sources say it is a starburst galaxy but NED didn't note this in its classification. Still, it seems quite likely after its interaction with two other NGC galaxies. NGC 4627 is 17,000 light-years in size including its plumes using the same distance.

The pair was discovered by William Herschel on March 20, 1787. NGC 4631 is in the original Herschel 400 observing program. My comments using a 12.5" f/6 scope at up to 150x on an excellent night in the New Mexico on April 27, 1984 desert reads: "WOW! edge on with many faint knots but no dust lane, Round companion appears larger than in photos but maybe I'm not seeing the full length with NGC 4631. In same low power field with NGC 4656." Arp's comment: "Knots resolved with 48-inch. Diffuse counter tail on companion."

NGC 4631 is often called the Whale Galaxy though I've also heard it called the submarine galaxy. The annotated image lists all galaxies that NED had redshift data on.

Arp's image: http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp281.jpeg

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

Related Designations for ARP281

ARP282

Arp 282 is an interesting interacting pair just under 200 million light years from us. It consists of a large but distorted spiral, NGC 169, and a small companion with tidal arms, IC 1559. Ned calls the small companion a SAB pec though I see no hint of spiral structure. Most papers I saw classed it as E3 or S0 which makes more sense to me. Arp classed the pair as Group character: infall and attraction, whatever that means. He explained a bit saying "Companion appears to rain into the nucleus of spiral." The famous Whale galaxy, Arp 181/NGC 4631 is similarly classed by Arp.

Distortions to NGC 169 include a core that is well west (left) of center as something seems to have drawn the arms on the east side way away from the core. Likely the companion passed by this side sometime in the past. While the companion seems to be "falling" into the core it likely is well in front of the galaxy after looping around the east end. The orbit is likely unstable and the two will eventually combine some time in the future. Note too that NGC 169 seems to have a large bulge of halo stars "above" (north) of the plane of the galaxy. This would indicate the companion may have made several passes to cause both tidal distortions.

Note at NED makes the following comments on the pair: "These two galaxies have dramatically different colors; galaxy A has very blue, star-forming colors; galaxy B displays the colors of a reddened elliptical, yet has a disk morphology." I assume A is IC 1559 and B NGC 169. Another note says: "Pair in contact, made up of NGC 0169 and IC 1559 MRK 0341 = IC 1559, a small peculiar lenticular."

The MGC catalog says of IC 1559: "It is of elliptical shape with the major axis having stubby ends. The continuous spectrum is diffuse in the blue-violet region and becomes brighter in the ultraviolet. H{alpha} is observed." Both galaxies were discovered by R.J. Mitchel on September 18, 1857.

I had a lot of problems processing this image due to the bright star, SAO 78148, right beside the pair. It is a K2 giant of 6th magnitude and cast all sorts of junk across the image that was a major pain to deal with.

The third member of this group, 11 arc minutes to the SW (lower right) is NGC 160. It is at about the same distance as Arp 282. It is classed as SA0(r) pec. One note says of it: "Very small nucleus, isolated at center of faint double (R). Non-interacting pair with NGC 0169." That is, it has a double ring structure. I assume that refers to the inner yellowish band around the core as well as the bright bluish outer edge to the galaxy. Normally the outer edge of a spiral fades away but this one ends abruptly after a narrow suddenly brighter rim. Some stars are seen outside this bright rim at either end but they also seem to end abruptly rather than fade into the background. So did it interact with Arp 282 sometime in the distant past to get this odd structure? NGC 160 was discovered by William Herschel on December 5, 1785 but isn't in either of the Herschel 400 observing programs.

Above NGC 160 and right of the bright star is UGC 354 at 240 million light years. A bit farther than the others but possibly a group member. Note that some catalog listings incorrectly show it as NGC 162. The Sky's database has this error. The description of NGC 162, however, shows it to be a very different object. It reads eF, stellar, 160 sp which translates to extremely Faint, starlike, NGC 160 south preceding. But UGC 354 certainly isn't starlike, nor extremely faint nor is NGC 160 preceding it across the sky but following it. Thus most feel that NGC 162 is one of many stars incorrectly thought to be faint galaxies when seen at the very limit of visibility in scopes of the era. It is likely the star east (left) of the top edge of NGC 160.

These 4 are the only galaxies in the field that NED shows redshift data. About 15 more galaxies are cataloged in NED (all IR emitting in the 2MASX catalog) though a few also carry extended LEDA designations. Thus most of the galaxies in the image are anonymous as far as I can tell.

Arp's photo with the 200" Hale telescope is at:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp282.jpeg

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

Related Designations for ARP282

ARP283

Arp 283 consists of two interacting galaxies, NGC 2798 right and NGC 2799. Arp classed them under Group Character: Infall and attraction. He adds this comment: "Arc of barely resolved knots curves into nucleus of larger galaxy". It does appear the interaction has created huge tidal plumes on NGC 2798 and has warped the disk of NGC 2799 into a sort arc. Unfortunately the night I imaged this wasn't very good with below average seeing and transparency so this image is well below what I'd have liked. Still, you can see a hint of the curve of NGC 2799's arc toward NGC 2798. This could be just a perspective illusion.

NGC 2798 is classed as an SBa or SBb galaxy depending on who you read. In any case, it is classed as a barred spiral. Its core seems so distorted. I don't see much of a bar and the spiral arms seem to come from nothing rather than end of a bar as you'd expect. Their beginning ends are 180 degrees apart as you'd normally see with a barred spiral. The interaction has obviously greatly altered the galaxy.

It shows no new stars in visual light but IR data shows massive star formation going on hidden behind extensive dust. The core region contains most of this star formation. The spiral arms are quite red, rather than blue. I can't tell if this is real or scattered dust has absorbed much of the bluer light letting only red through. It was discovered by William Herschel on January 14, 1788 though he missed NGC 2499 or more likely saw them as one object. It isn't in either of the Herschel 400 observing programs.

NGC 2799 is seen nearly edge-on. Most sources consider it an SB galaxy, that is a barred spiral, but a few consider it as Sc. Considering it is edge on and highly distorted this is an argument that I doubt can be settled.

It appears that if NGC 2799 is in front of NGC 2798 that the dust lane in NGC 2798 is really dust pulled off the end of NGC 2799. Otherwise, it is rather hard to explain I'd think. It was discovered on March 9, 1874 by Ralph Copeland.

The pair appears to be about 90 million light-years away.

Actually, this is a three galaxy system. The spiral below them, UGC 4904, shows the same redshift as the two others. It too shows strong signs of interaction. In fact, it resembles M64 as being a "black eye" type galaxy though, in this case, is more a "reddish brown eye" in my image. The core also seems made up of several condensations with only a rough indication of spiral structure. It too is classed as a barred spiral though it appears too chaotic for me to see that structure. It may show at other wavelengths, however. In any case, it appears all three have interacted with each other.

On the far left a bit above center are two galaxies, the western being fainter. It is 2MASX J09185002+4200433 an IR galaxy about 560 million light-years away. The other is 2MASX J09185523+4200133 also at about 560 million light-years.

Halfway back west toward Arp 283 and below a bright orange star near a brighter blue one is the small nearly vertical galaxy SDSS J091808.53+420020.8 at 880 million light years. Continuing west and up a bit past a white star is the somewhat larger appearing galaxy SDSS J091756.39+420054.1 at the same distance so they form another pair. Just below it and a bit left is the star-like galaxy SDSS J091756.99+420039.3 but I have no redshift data on it.

Starting at the lower left corner move along the bottom, under a star then pass over a much fainter one and you come to a small galaxy most of which is in the frame with only its very south end cropped. This is SDSS J091831.58+414533.0 at 1.3 billion light years. Up and to its right is a somewhat larger redder and brighter galaxy. It is 2MASX J09182805+4146242 at 1.8 billion light years. It obviously is a really big galaxy to be magnitude 17.5 at that great distance.

There are other galaxies and quasars in the image. The above galaxies and the other distant objects are shown in the annotated image with their distance in billions of light years per NED using their 5 year WMAP data.

My image has several very distant quasars so I've also attached an annotated image point these out and the distances to some of the other galaxies in the image.

This one is located in Lynx. Arp's image is at:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp283.jpeg

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

Related Designations for ARP283

ARP284

ARP 284 is a pair of interacting galaxies NGC 7715 and NGC 7714 left to right. Arp classifies these under the heading of "infall and attraction" whatever that means. They are located a bit over 100 million light-years away in the constellation of Pisces. NGC 7714 is a starburst galaxy. It has strong H alpha emission though I didn't take it in that light so it's not well seen in my shot. The starburst occurred some 3 to 9 million years ago. Note the odd reddish tidal arm at the lower right that just doesn't seem to fit the rest of the galaxy. The red color is due to mostly H alpha light so it is one huge area of ionized hydrogen. The companion NGC 7715 has H alpha emission and is not a starburst galaxy. It is classed as an irregular galaxy and is not an edge on spiral as it might appear. 7714 is an SB spiral that has been highly distorted by the interaction. Its core has emission lines that classify it as a LINER galaxy, a type with an active black hole in its nucleus.

The bright star at the upper right is also very interesting. It is SAO 128268 and is 126 light years away. What is interesting is that it is moving very rapidly through the sky. I was checking the POSS1 plates taken in the 50's at the Hale Observatory on Mt. Palomar when I noticed it wasn't in the same place as it is in my photo. Click this link http://stdatu.stsci.edu/cgi-bin/dss_search?v=poss1_red&r=23+35+25.46&d=%2B02+13+48.6&e=J2000&h=15.0&w=15.0&f=gif&c=none&fov=NONE&v3= to see that plate image. Note the two stars on either side of it are above it in that photo yet below it in my shot. It is moving upward and a bit to the east at a rate of about 1/3rd of a second of arc per year. In the approximately 50 years between the photos, the motion is quite obvious. Some stars show a high proper motion (movement through the sky) because they are close, Barnard's star is an example, while others do so because they really are moving fast. In this case, it is a little bit of both. NGC 7714 was discovered by John Herschel on September 18, 1830. It's not in either Herschel 400 program. NGC 7715 was discovered by Bindon Stoney on November 4, 1850. An HST image of NGC 1714 is at: http://cseligman.com/text/atlas/ngc7714hst.jpg but only shows a short piece of the arm that connects the two.

The star just below Arp 284 is one of the very few in all my images that is visible to the naked eye. It shines at magnitude 5.7 which means you can just barely see it on a dark moonless night from a location far from any lights. Averted vision (that is not looking right at it but somewhat to the side) will likely be necessary to see it. So it isn't an easy star to see but it can be seen. Unfortunately, that makes it so bright it made processing this image very difficult. Most of the scientific papers on the galaxy pair mention their measurements are likely tainted by the glare of the star so even the big boys are bothered by it. It is a spectroscopic double star about 100 light-years away known as HD 221950 or 16 Psc. The latter indicates it is a naked eye star, the 16th in Right Ascension order in the constellation of Pisces. These numbers were assigned long ago so precession (a ~26,000 year wobble of the earth's axis) has changed the RA order of the stars in some cases but the original order numbers have been kept.

I've prepared a rather sparse annotated image that has little on the close galaxies but for those in ARP 284 but does show much more distant quasars and a galaxy cluster. Arp made a big deal about quasars around his active galaxies claiming the redshift of them had nothing to do with distance. By his logic, they weren't active massive black holes in distant galaxies but were something ejected from active galaxies. Redshift somehow related how long ago they were ejected. Higher redshift indicated they were ejected before those with lesser redshift. Somehow this involved electrons that changed with age. I've tried reading several of his books and other books trying to explain his logic and I end up a screaming basket case each time so may have this somewhat scrambled. With all the quasars around this actively interacting pair, he'd have had a field day though all have a rather similar redshift. I've not dug through his books to see if he mentions this one or not. My brain can't handle much more of his ideas.

Arp's image: http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp284.jpeg

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

Related Designations for ARP284

ARP285

Arp 1 is obviously the first entry in his catalog and falls under the classification: Spiral galaxies: Low surface brightness. It is classed as an SC spiral. The other low surface brightness galaxies in his catalog are all small irregular dwarf galaxies of the Magellan class. This is the one exception. It is about 230 million light-years distant and is in the front leg of Ursa Major. Thus nearly twice as distant as Arp 285 and therefore a far larger galaxy. Though Arp has always argued against redshift data as a distance indicator, making him a maverick or crackpot depending on your point of view. While it is of low surface brightness it was still much easier to image than Arp 2 was. In fact, I was imaging Arp 285 not even realizing it would be in the same field of view. If I had, I'd have moved it down a bit to better frame both objects. It appears to be a rather classic two arm spiral except the arms are thinner than normal. Also, it has a very small core only a few seconds of arc across that is far brighter than the rest of the galaxy. I found no detail in the core, just an evenly bright star ball of population 2 stars. Those are stars that have low "metal" content having been formed for the most part about the same time the galaxy was born, likely over 10 billion years ago. Thus only yellow, orange and red stars still survive giving it the typical color of a galaxy core. The arms, like in most spirals, are composed of population 1 stars like our sun that have been formed long after the galaxy was formed. Those giving the arms their blue color are likely only a few 10's of millions of years old, up to a thousand times younger than those in the core. It was discovered by R. J. Mitchel on January 9, 1856.

Arp's photo of this galaxy with the 200" telescope is at:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp1.jpeg
His only comment deals with the image. He says of it: "High-contrast print of low surface-brightness spiral."

__________________

Arp 285

This is an interacting pair of galaxies that are rather widely separated. The upper is NGC 2856 and the lower NGC 2854. Arp classed the pair under: Group Character: infall and attraction. I don't know what he saw that caused this classification, maybe it is the odd linear feature appearing to spear NGC 2856. Arp referred to it saying; "Narrow tail leads away from north nucleus." Redshift shows an approximate distance of 130 million light-years and is seen in the front leg of Ursa Major.

Each shows some hint of interaction. Obviously, there's that "narrow tail" which actually came from NGC 2854 per the paper cited below. Also, notice that there are tidal tails coming off both arms of NGC 2854. The southern one looks a bit like "smoke".

A paper by Beverly Smith talks about the "narrow tail" from NGC 2856 to use Arp's term. It is not a jet at all. Here's an excerpt from her abstract.

"This system contains a striking example of "beads on a string": a series of star-formation complexes ~1 kpc apart. These "beads" are found in a tail-like feature that is perpendicular to the disk of NGC 2856, which implies that it was formed from material accreted from the companion NGC 2854. The extreme blueness of the optical/UV colors and redness of the mid-infrared colors implies very young stellar ages (~4-20 Myr) for these star-forming regions. Spectral decomposition of these "beads" shows excess emission above the modeled stellar continuum in the 3.6 ¼m and 4.5 ¼m bands, indicating either contributions from interstellar matter to these fluxes or a second older stellar population. These clumps have  12.0 < M B<  10.6, thus they are less luminous than most dwarf galaxies. Our model suggests that bridge material falling into the potential of the companion overshoots the companion. The gas then piles up at apogalacticon before falling back onto the companion, and star formation occurs in the pile-up. There was a time delay of ~500 Myr between the point of closest approach between the two galaxies and the initiation of star formation in this feature." The full paper is available free at the link below.
http://arxiv.org/abs/0803.4218
Images:
http://www.etsu.edu/physics/bsmith/research/sg/arp285/arp285.html
Beads on a string image:
http://www.etsu.edu/physics/bsmith/research/sg/arp285/arp285clumps_labels.jpg
This may also explain Keenan's System, Arp 104.

The two galaxies were discovered by William Herschel on March 9, 1788. Neither made either of the Herschel 400 observing programs.

Arp's 200" telescope photo of this pair is at:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp285.jpeg

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Other galaxies in the image:

The tiny galaxy on the NE edge of Arp 1 is SDSS J092445.35+492234.2 at 2.3 billion light-years.

Above it, the small blue SO looking galaxy is SDSS J092448.70+492353.7 at 380 million light-years.

And above it near the top of the page is SDSS J092450.37+492513.7 at a nice round 1 billion light-years.

East of Arp 1 the larger slightly orange elliptical like galaxy is the much bigger and brighter CGCG 238-051 with no red shift data.

Eastward to the edge of the image is a pair of galaxies known as CGCG 238-053. Oddly only the easternmost one has red shift data. That indicates a distance of 380 million light-years. The western galaxy looks distorted with a drawn out arm. It appears they may be an interacting pair.

SE of Arp 285 is a pair of small blue galaxies. Left to right they are: SDSS J092424.40+490815.3 and SDSS J092423.29+490821.5. Red shift data is available only for the first. That puts it at 980 billion light-years nor is there red shift data on the small galaxy to the NW of this pair.

Nearly due east of the above pair is the very orange galaxy SDSS J092456.78+490746.6. Usually such a color indicated a great distance and that's the case here with a red shift distance of about 2.2 billion light-years.

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

Related Designations for ARP285

ARP286

Arp 286 consists of three galaxies, NGC 5560, NGC 5566 and NGC 5569 right to left in my image. They are in the constellation of Virgo about 80 to 90 light-years distant. Arp put them in his category: Galaxy groups: Infall and attraction. This likely refers to NGC 5560 and NGC 5566 as NGC 5560 appears warped and drawn out by the gravity of NGC 5566. NGC 5566 itself seems distorted. The outer "arms" look more like plumes and are somewhat unsymmetrical. Also, the northern one has a prominent reddish dust lane that's hard to explain other than by tidal effects. Also, I think its disk appears slightly warped as well. Arp's comment on this entry reads: "Connection not visible." I see no tidal star streams connecting any of the three, though there is a faint plume coming off the south end of NGC 5566 heading to NGC 5560. A much longer exposure might show a connection. NGC 5569 seems unfazed and likely is more a line of sight member that appears far closer to the other two than is really the case.

NGC 5660 was discovered by William Hershel on May 15, 1787. It is in the second Herschel 400 program. He found NGC 5569 3 years earlier on March 19, 1784. NGC 5666 was discovered by John Herschel on May 9, 1825.

NGC 5560 is classed at NED as SB(s)b pec and has a redshift distance of about 90 million light-years. NGC 5566 is classed as SB(r)ab and is a LINER galaxy. Redshift data puts it at about 80 million light-years. Tully-Fisher measurements put it at about 86 million light-years. Certainly, it and NGC 5560 are likely quite close whichever measurement you choose. NGC 5569 is classed as SAB(rs)cd. By redshift, it is a bit over 90 million light-years distant though one Tully-Fisher measurement puts it far closer at about 57 million light-years. I doubt this measurement as it involves rotational velocity measurements that are difficult with near face on galaxies. There appears to be a 4th member of the group in the image. A dwarf galaxy at the very top of my image a bit left of center has a redshift distance of 90 million light-years.

NED has distance data on only a few of the galaxies in my image. I've made an annotated image showing these. The field is rather rich in distant quasars.

Arp's image
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp286.jpeg

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

Related Designations for ARP286