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."

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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

ARP287

ARP 287 is a pair of interacting galaxies, also known as NGC 2735 and NGC 2735A, located in northern Cancer. Arp put these in his category: Double galaxies, Wind effects. In fact, it is the very first entry in this category. Arp said of the pair: "Slanted parallel streamers off each edge of main galaxy." That certainly is the case. They certainly are strange compared to the standard plumes seen in interacting galaxies. Many years ago I spent many days playing with software to model interacting galaxies. I found it easy to make all varieties of "normal plumes" seen in his catalog but I never could make the "wind effect" type no matter what I did. Such software was primitive (as was the computer) compared to today's, still, I've not seen a simulation that creates these types of plumes. If anyone has run across one please let me know. Besides the streamers note that there is a dust lane between them that extends completely across the main galaxy to the companion. So are the streamers really coming from the companion as the dust lane appears to be? Seems possible to me.

Redshift data at NED puts the main galaxy at about 125 million light years and classes it as SAB(rs)b? pec. Many papers, however, class it as a "Red SBa" spiral. The companion is a blue compact galaxy classed as Im: pec and showing a redshift that puts it a bit further away at 130 million light years. This difference is easily within the normal range of galaxies in groups. They are likely at virtually the same distance. The thin sliver of a galaxy to their east (left) is also at the same distance (SDSS J090253.00+255612.5). So this is more of a triple than a double system. It just isn't interacting with the other two. NGC 2735 was discovered by Édouard Stephan on February 26, 1878.

Arp later noted that quasars seemed to be found around his strangest galaxies and thought that the low redshift ones were nearest the galaxy and the largest redshifts belonged to the most distant. Most astronomers considered this coincidence but it led Arp the belief that some, if not all, quasars were actually nearby objects ejected from these strange galaxies. He even came up with what many would call crackpot physics to support this idea. This and other factors led to him being kicked off the 200" scope and sent packing for Europe where a few still thought at least some parts of his ideas needed to be further investigated. Few if any buy them today, however. Geoffrey Burbidge, who died before Arp, was one of the few that still held out hope for non-cosmological redshift but not using Arp's "warped" physics. `In the case of Arp 287, there is a "nearby" quasar just north of the main galaxy that is "only" 4.9 billion light years distant. See the annotated image to find it. A bit further out along the same line is one 8.2 billion light years out and following the line the other way even further is one of 11.6 billion light years. But if you go further the idea breaks down with a quasar to the northeast of the last one that is only 4.4 billion light years away, the lowest redshift of all. But if you want to save the nutty idea then maybe these are something different. It was partly due to Arp's ability to rationalize away exceptions that helped ruin his reputation. All scientists constantly come up with wrong ideas. The good ones know when to let go and move on. For some reason, Arp found this impossible as to his anomalous redshift idea.

The annotated image. as usual, shows the distances to galaxies and quasars in billions of light years. The limiting magnitude of the image appears to be about magnitude 23.5 for the processed image. The raw luminosity images goes a bit deeper. I've labeled one such galaxy with its green magnitude. It is one of dozens you will see if you enlarge the lower southeast portion of the image. To me it appears there's a galaxy cluster there but I found none listed at NED for this area. Looking at the image though you will see the galaxies tend to fall into groups. There's one at about 1.1 to 1.3 billion light-years, another at about 4.3 to 4.7 billion light years. If there's no redshift listed by an object that means I didn't find one at NED. This includes some rather "bright" galaxies.

The image contains 6 asteroids. Late evening images to those a few hours after local midnight show those that are moving in retrograde motion if near the meridian where I image. Thus they move "backwards" from east to west as we pass them taking our shorter and faster inner track around the sun. But this image was taken just before dawn and caught them in their "normal" west to east motion. So they are moving right to left. But the tracks are short indicating they soon will be changing to retrograde motion. The short tracks make them harder to pick out so I've labeled them in the annotated image. 3 are magnitude 19.7. The obvious bright one above Arp 287 is magnitude 18.6. The faintest at magnitude 20.1 is just above a "small" galaxy in the lower right corner. The one right on the bottom edge near the right edge as well is 19.9, I barely caught it. One of the 19.7 ones is named Desai. Seems if you do well in the Intel (used to be Westinghouse) science contest you get an asteroid named after you. This is the second I've run across in my images. The naming citation reads: "Kshitij A. Desai (b. 1992) was awarded second place in the 2008 Intel International Science and Engineering Fair for his medicine and health sciences project. He attends the Michael E. DeBakey High School for Health Professions, Houston, Texas, U.S.A." Do they have high schools for astronomy professionals?

Arp's image:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp287.jpeg

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

Related Designations for ARP287

ARP288

ARP 288 is a triple galaxy system in the very northeast corner of Virgo about 320 million light-years away. Arp put it in his catalog under Wind Effects. Apparently referring to the northern member of the trio, NGC 5221. It has some faint but huge plumes. South of it is the odd galaxy pair of NGC 5222. It consists of a small blue spiral and a larger golden elliptical galaxy. Arp's comment refers to NGC 5221 when it says: "Streamers in both directions from edge of spiral". Why he included the pair that is NGC 5222 I'm not sure. They are related in that their redshift is about the same but neither shows distortion that could easily explain NGC 5221's plumes.

NED classes NGC 5221 as Sb. I'd have thought the plumes would earn it a pec designation but apparently not. The spiral itself is quite ordinary looking though I suspect that is due to our highly tilted viewing angle. One note at NED says it is a barred spiral.

NGC 5222 is an odd pair of galaxies, a small blue Sa spiral and a far larger elliptical (E). The spiral has some distortion, best seen on the Sloan or Arp images. Redshift puts them about 3 million light years further away though this is likely due to their motion about a common center of gravity rather than a real difference. Still, these two have virtually the same redshift indicating a closer relationship. The papers I found consider the elliptical as the cause of NGC 5221's plumes. I'm not so sure. The distortion to the much smaller and likely nearer blue companion is not nearly as great yet such a tiny galaxy should be greatly distorted. Though if the interaction is just starting this would be the case. Still, I'm not convinced.

The other large galaxy in the image is NGC 5230, an M101 like spiral. It has a redshift distance of 324 million light years. One note at NED says it might be distorted by the elliptical NGC 5222. Again I'm having problems with this. Shouldn't the elliptical show some distortion after interacting with two large and one small galaxy? I can understand the small one but not the other two. Would it be more likely that NGC 5221's plumes are due to it interacting with NGC 5230 in the distant past? Seems more likely to me. Nothing I found in the literature suggests it, however. Both were discovered by William Herschel on April 12, 1784 but aren't in either Herschel 400 observing program.

There are quite a few other galaxies in the group in my image. The largest after these three is NGC 5226, the small spiral north of NGC 5221. At a redshift distance of 346 million light-years, it could be a distant member though again this might be due to its motion relative the rest rather than a true distance difference.

All possible members with redshift data are shown by name in the annotated image. Those without a catalog designation are too distant to be considered possible members of the Arp 288 group.

Arp's image:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp288.jpeg

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

Related Designations for ARP288

ARP289

ARP 289/NGC 3981 is a spiral galaxy in far eastern Crater just barely in Crater rather than Corvus. At almost 20 degrees south it is the most southern Arp galaxy I've been able to image. Its distance is put at about 100 million light-years by redshift and about 75 million by other methods, mostly Tully-Fisher. Arp put it in his category of Double Galaxies with wind effects. His comment reads: "Very faint diffuse streamers." NED classes it as SAB(s)bc pec.

The problem is that most sources don't see the second galaxy. Of the notes at NED only a very old one (1968) about the time of Arp's Atlas speaks of it being an M51 like galaxy. Apparently, Arp and the note are referring to the blue blob at the south end of the brighter part of the galaxy. The Kanipe-Webb book on the Atlas identifies the blue blob as VV8B. VV stands for the Vorontsov-Velyaminov Interacting Galaxies catalog. But NED shows VV8B as Part of Galaxy, not a separate one. Most today seem to consider the object a massive star forming region in the galaxy rather than a separate galaxy. So what distorted it? Like Arp 184/NGC 1961 some say the distortion is just the way this one was made. Even if true how do you explain it was "made" so differently? Hubble hasn't taken but one very underexposed and useless image showing nothing I can recognize so no help there. Kanipe-Webb just leaves the issue of one or two galaxies here as open to debate. The galaxy was discovered by William Herschel on February 3, 1788 but isn't in either of the H400 observing programs.

I can't buy those plumes being just the way this galaxy is. I think it merged with something and the blue blob something left over from the merger which created the huge plumes. I'd love to see some rotational studies of it but couldn't find anything on this.

Modern paper (1994 -- latest at NED) read:
"The two well-defined principal arms of the grand design type in NGC 3981 have high surface brightness. They can be traced for about half a revolution outward from their origin near the center until they abruptly decrease in surface brightness, become more open, and exhibit a smooth appearance. It is the plume-like appearance of the very faint outer "arms" that gives the notation (tides?) in the classification, although no companion is present. The designation simply describes the morphology, not the cause, which probably is not interaction via an encounter but rather is endemic to the galaxy. The heavy main print shows faint HII regions in the outer extensions of the inner arms and in a separate outer arm not connected with the two main inner arms. This third faint outer arm can be faintly seen as a straight segment along the major axis (at the top of the facing print) which then sweeps at a large pitch angle to the right in the orientation of the image here."

1968 paper says:
"Third, after M 51 and NGC 7752-3, classical example of interacting galaxies, the bridges to one of them being the spiral arms of the other, caught by a companion. It is now well-established that M 51 is not unique of its kind, but in its time was an important proof of the generality of the composition and origin of spiral arms and bridges between galaxies. Type: vB - Sbt, Morg - fS6. Photo: VV Atlas No. 8; Arp No. 289. Companion here of type Irr?."

M51 is Arp 85, NGC 7752-3 is Arp 86 which is a true M51 type galaxy pair. Neither paper mentions merger so maybe I'm way off base. Still, I like the idea.

Being so far south my image is rather poor. If seeing would hold this low for several nights I could take a pure RGB image which would be much clearer as I could remove the prism effect that so elongates the stars in my luminance channel. Even RegiStar had trouble aligning the color channels. I probably should have run them through a second time as there's still some nasty prism colors in the corners. Most of which I removed by brute force processing, that is, clone it out. This prism distortion greatly reduced my resolution. Most nights I can't go this low at all so I'm just happy I could get this result. Due to atmospheric absorption this low a lot of light was lost. Even with 60 minutes rather than my normal 40, I couldn't go nearly as deep as normal. Still, I went nearly as deep as most images on the web taken by more southerly located telescopes.

The galaxy is out of the Sloan survey field so there's a dearth of information on the other galaxies in the field.

The bright oval red galaxy in the upper left corner is MCG -03-31-003, a SAB0 galaxy with a redshift virtually the same as Arp 289. It is likely a member of the same group as Arp 289. I see no distortion to it so it likely has nothing to do with the distortion of Arp 289, just an innocent bystander. Just below at the 5:30 position is a very tiny, likely dwarf galaxy, [MPP88] 1154-1935. It has a very small redshift putting it possibly much closer, say 20 million-light years away. If true it is a very tiny galaxy. I have some trouble with this. It likely is further away than its pure redshift indicates. MPP is the Monk Penston Pettini galaxy catalog. I don't know what characteristic it is using for deciding what galaxies to include. No other catalog lists this galaxy that NED has in its database.

The "large" spiral galaxy half-way down the left edge of my image is ESO 572- G 024. It is classed as SBd?. Its redshift is also about the same as Arp 289. Likely another member of its group but again looks quite undisturbed. A couple more likely members of the group are out of the top of my frame. For some reason, I thought they were lower so moved the galaxy up. Think I was looking at the declination and assuming it was positive rather than negative. I've done that before. So I missed them. Just more smudges so not much missed. The only other "interesting" galaxy in the image is the smudge of a galaxy toward the right center of the image. It is ESO 572- G 016. Nothing much is known about it. The rest of the galaxies in the image carry unusual catalog names and no red-shift distance if they are listed at all, most aren't.

Arp's image oriented the same as mine for a change:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp289.jpeg

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

Related Designations for ARP289

ARP290

ARP 290 is classed by Arp as Group Character: Wind Effects. It does appear "wind blown". The small galaxy is IC 195, the wind blown one is IC 196. Both have a redshift consistent with a distance of about 155 million light years and are magnitude 14 and 13.6 respectively so within range of a 10" scope from a dark site. They are located in Aries.

IC 195 is classed as SAB0 while IC 196 is SBb. Both were discovered by Lewis Swift on October 20, 1889

The only somewhat blue galaxy in the image is SDSS J020352.74+144140.0 SE of Arp 290 3 minutes, just west of the nearby asteroid trail. It is 740 million light years away yet still somewhat blue. The little vertical galaxy below it is 2MASX J02035353+1440074 and IR galaxy at 740 million light years.

The tiny vertical galaxy above IC 196 is 421 million light years distant so not related to Arp 290.

Most interesting to me is 2MASX J02032466+1441521, another strong IR emitting galaxy. It is the "tiny" face on spiral to the west-southwest of Arp 290. It stands out for being so red yet being a spiral. It certainly isn't a tiny galaxy as it is 1.7 billion light years distant. It has to be one heck of a big galaxy. Is the red due to galactic reddening.

There are 3 asteroids in the image. The bright one near Arp 270 is (113736) 2002 TD155. Below it near the very bottom of the image is much fainter 2008 UU198. It was discovered only days before I took this image, though I didn't know this at the time. As indicated by its designation it was the 4970th asteroid discovered after October 15th and before November 1. These automatic systems are finding them rapidly! I took this image Oct. 31 UT. The third asteroid is directly west of the second and a bit fainter. It is 2003 WC175. So while fainter it was found almost 5 years earlier. It is faint as it is estimated, by the minor planet center, to be magnitude 19.7.

SDSS:
http://astronomerica.awardspace.com/SDSS-3/IC195.php

Arp's image of this pair with the 200" Hale telescope is at:
http://ned.ipac.caltech.edu/level5/Arp/Figures/big_arp290.jpeg

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

Related Designations for ARP290