NGC4893

My main subject of this image was NGC 4893 in the image center but the field turned out to be far more interesting than I suspected. The field is in Canes Venatici about 1.5 degrees southeast of Cor Caroli, the constellation's brightest star. NGC 4893 is either one or two galaxies depending on who you read. The NGC Project considers it two galaxies made up of IC 4015 and IC 4016. NED and Seligman consider NGC 4893 to be only IC 4015. IC 4016 is sometimes known as NGC 4893A which Seligman calls stupid since it already has a perfectly valid IC designation. First time I recall that term used in naming galaxies. Actually, there's a third member of this group, starlike ASK 519181.0. NED refuses to classify any of these. The NGC Project says the northern galaxy is S? while Seligman gives it two classifications. Under the NGC 4893 number he says E2? but under the IC 4015 entry he says E2? pec?. The galaxy was first discovered by Heinrich d'Arrest which Dreyer recorded as NGC 4893 on April 24, 1865. On March 21, 1903 Max Wolf found it but got the coordinates a bit off so Dryer recorded it as a separate entry in the IC catalog as 4015.

IC 4016 was found by Wolf at the same time and given the entry IC 4016. NED again doesn't classify it, The NGC Project says S? while Seligman gives two classifications for it. Under his discussion of NGC 4893, he says IC 4016 is S?? (that double question marks again) while under its own entry in the IC section of his web page he says it is S0? pec, only one question mark.

It is quite obvious these two galaxies and likely the third are interacting and have been highly distorted. It could be the starlike galaxy has lost all its outer stars leaving only a core. The mess is about a half billion light-years distant. I'd love to have the HST look at this mess as I was unable to find any detailed images of this group. Measuring the size of these considering that they are in common halo is difficult. I measured the east-west halo diameter of each rather than the larger combined north-south halo. That gives a size of 104,000 light years for NGC 4893 and 40,000 for IC 4016.

Several other NGC galaxies are in the image. In the upper right corner is the classic spiral NGC 4868. It is listed as SAab? by NED, Sa by the NGC Project and type Sab? by Seligman. It was discovered by William Herschel on March 17, 1787. At only 220,000 light-years it is less than half the distance of the NGC 4893 group. While it appears much larger that is due to it being much closer. I measure it at just about 100,000 light-years in size. It isn't in either of the Herschel 400 observing programs.

Far larger in the upper left corner is NGC 4914 a huge shell elliptical galaxy. I had no idea of the shells as nothing I read before taking the image referred to them. The shells extend far out though they don't come through well in the color image due to my insufficient exposure time. If you look very closely you can see the northern shell extends to near the top of the frame. This makes the galaxy huge. I measure it at 380,000 light-years. If only the shells obvious in the color image are used it is still 234,000 light-years across. Classification confusion continues as NED and the NGC Project say simply E, Seligman says E4 while one paper says E5/S0. No one mentions the shells but the paper thinks it has found within the galaxy the remains of one it ate. Shells are the result of such a diet so they may be right. I couldn't find it however in my image and only a faint hint of it in the Sloan image. It was discovered by William Herschel the same night as NGC 4868 and is in the second Herschel 400 observing program. Unfortunately, my notes for that program didn't survive the move up to Minnesota.

We aren't done with NGC galaxies in the image. In the lower right corner is NGC 4870. NED again refuses to classify it. The NGC Project says S while Seligman says S(rs)a?. It was discovered by Lawrence Parsons on April 1, 1878. I measure it at 137,000 light-years in size. At nearly a half billion light-years distant it is likely a member of the NGC 4893 group. Its disk has an odd gap in the northern half not seen in the southern half.

IC 4027 as a barred spiral that too is likely a member of the NGC 4893 group. While NED doesn't classify it Seligman says SB0?? (that double question marks again). Max Wolf had a very productive night on March 21, 1903 having found this and the next three IC galaxies all as well as others mentioned above that night. I measure its size at about 72,000 light-years.

Next is IC 4034 which only Seligman classifies saying it is E0?? trying to drive me nuts with that double question mark again. I measure its size at 56,000 light-years. At 400 million light-years it apparently is not part of either of the two main groups in this image but does have a companion, IC 4038. Only Seligman classifies it and to drive me insane says it is S0??. It has some faint extensions that give it a somewhat larger size of a bit over 100,000 light-years.

The last IC galaxy in the image is IC 4043. Finally, NED classifies it saying Sc-IRR. Apparently, it can't make up its mind. I can't recall that combination before. Seligman has the same indecision as he says SBd/Irr?. At least only one question mark this time. It appears to be part of the group of much larger galaxies at 220 million light-years. I measure it at 74,000 light-years in diameter

This field is full of double identities and even a triple. ASK 519150.0 is also listed as LEDA 2096904 at the same position but different distance. A quasar is listed at twice also at two very slightly different distance. While I annotated only one entry for ASK 519156.0 it is also listed at a very slightly different distance under a Sloan survey ID and at yet another very slightly different redshift under a 2MASS designation. All round to 2.61 billion light-years so I didn't note this. Still, I've not run into this before in any field I've taken.

To add to the confusion there's a neat low surface brightness, very blue galaxy on the eastern side of the image near LEDA 2094904 (another galaxy likely part of the NGC 4893 group). This galaxy isn't listed in any survey I have. Yet NED shows an entry in the Sloan survey for what to me looks like a piece of a north going arm. I've noted it in the annotated image though the galaxy itself gets a question mark (only one) since I can't find it anyplace. Well below this object is LEDA 2092313 a dwarf likely related to the others at about 220 million light-years. it has a bright star cloud at its southern end. At first, I thought it might be a field star but I've verified it is a star cloud in the galaxy. There's lots more to explore in this image but it would take a book to cover it all and I've likely lost 99% of you by now anyway.

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

Related Designations for NGC4893

NGC4911

NGC 4911 is one of the few spirals in the Coma Cluster. Due to interaction with NGC 4911A to the southwest, the galaxy is surrounded by a huge faint plume of stars pulled from it. Other galaxies in the cluster have similar large plumes around them such as the red disk galaxy NGC 4919 about 5 minutes east-northeast of NGC 4911. The HST has taken the best image of this galaxy and has a more complete discussion about it. If you have decent internet service ignore the warnings and download the "highest-quality" image, about 15 megabytes in size.
http://hubblesite.org/newscenter/archive/releases/2010/24/image/

The largest and brightest spiral in the Coma Cluster is NGC 4921. It is rather red and the arms rather indistinct as star formation is very low in this galaxy. Likely collisions and encounters with smaller galaxies in the cluster has stripped it of most of the dust and gas needed to fuel star formation. Star clusters often kill galaxies as the constant close encounters and mergers disperse the dust and gas that would fuel star formation. Spread around the core of the cluster it is too hot to condense to form more stars or galaxies. Maybe in billions of years as the galaxies in the cluster cool and die this dust and gas will cool and condense sufficiently to create more galaxies. Or will the radiation of the first stars to form disperse this gas preventing and further star formation? A more complete discussion and false color image of this galaxy by the HST is at:
http://spacetelescope.org/news/heic0901/
The orientation is similar to mine being rotated a bit clockwise from north at the top.

Containing over 1000 galaxies the Coma Cluster -- Abell 1656 is the largest, richest "nearby" galaxy cluster being about 320 million light-years away. It is anchored by the two huge elliptical galaxies, NGC 4874 and 4889. NED puts the long diameter of NGC 4889 at 2.8 minutes of arc. That would make it about 260,000 light-years across. In December 2011 it was announced this galaxy is the home of the largest known black hole with a mass of 21,000,000,000 solar masses. Though the error bar for this is huge ranging from 6 to 37 billion solar masses! NGC 4874 is nearly as large but apparently doesn't harbor a record-smashing black hole. It has another number 1 claim. It has 30,000 globular star clusters. Though, many, like some around our galaxy are now thought to be the cores of dwarf galaxies it has been "feeding" on for the past few billion years. The stars were stripped from all but the cores of these dwarf galaxies leaving something that looks much like a typical globular cluster, only larger.
http://www.spacetelescope.org/images/potw1138a/
To confuse this globular issue a note at NED reads: "The power spectrum for NGC 4874 is clean and the fit is very good. NGC 4874 has a normal globular cluster population." http://iopscience.iop.org/0004-637X/550/2/503/pdf/52870.web.pdf (page 520)
I'm not sure how you reconcile these two statements.

Obviously, doing one of my typical annotated images would be a masochistic nightmare. Instead, I did note all NGC, IC and CGCG, KUG and GIN galaxies. Distance was not noted as all are at members of the cluster so are about the same distance from us. I left out several hundred of 2MASS and Sloan Survey cataloged galaxies. I also saw over one hundred very distant galaxies listed. I decided to mark those over z=0.5. Then I ran into a problem. Most were from a catalog listed as [ANM98]. After trying to locate 10 of them without success I gave up. NED lists their position as uncertain. But does indicate they should be in a 30" error circle. With so many galaxies in such a small area, a 30" error circle made identification impossible. There was no explanation for this huge error bar. One from the Sloan survey at 5.9 billion light years and fainter than nearly all of the unidentifiable galaxies was easily found under NGC 4874. I did mark that one.

Normally I'd go into who discovered these many galaxies and when but there are just too many. I covered some of them in the ComaCluster post. You are on your own for the others.

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

Related Designations for NGC4911

NGC4922

NGC 4922 is a pair of colliding galaxies on the northern edge of the Coma Galaxy Cluster that Arp didn't include in his atlas. Some papers see three galaxies here but most see only 2. NED shows no object at the position of the middle galaxy of the three. Nor can I see anything there in the Sloan image though that is overexposed. No matter how I stretch my image is anything seen at the middle galaxy's position: 13h 01m 24.67s +29d 18' 33.0". I'm only going to address the two seen in my image.

The southern galaxy is listed by NED as Sb Sy2. How you get Sb out of that mess I don't know. Likely that's a good estimate of what it was before the collision. It does have a nice blue plume to the south but otherwise is surprisingly red in color. The northern galaxy is listed at NED as S;HII;Sy2 LINER. That's a lot for that little guy. The NGC project has a classification of E0 for NGC 4922. I can't tell if that is for one of them or both or what. In any case that's quite a difference of opinion. The Seyfert classification of both is likely due to the black holes being well-fed thanks to the collision in progress. The strong red color of both would seem to indicate there's been no star formation in these guys except the outskirts for a few billion years. Something seems to have stopped star formation long ago. The plume, however, is very blue so has new stars. The pair was discovered by Heinrich d'Arrest on April 19, 1865.

Several other Coma Cluster members are in the image, many are small and many have very low surface brightness. For that reason, I labeled by name those that appear likely cluster members. The big ones have IC numbers or an MCG listing. The rest have rather obscure and usually quite long catalog names.

While the cluster with the common name of Coma Cluster is Abell 1656; a much smaller, in angular size at least, Abell 1661 is also in the image but instead of being about 330 million light-years distant like the famous Coma Cluster, it is 2 billion light-years away and can be found in the lower part of my image a bit left of center. Right below it is a pair of galaxies, one a member of the Coma Cluster (famous one) and the other a much more distant galaxy though they do look like they are very close together they are some half billion light-years apart.

Several other distant galaxy clusters are in the image if the distance to the anchoring bright cluster galaxy is different than that of the cluster by redshift measurement I list both with the cluster's distance first. If the distance has a "p" after it it is photographically determined which carries less accuracy than spectroscopic distances. If the BCG has a spectroscopic distance that is likely the more accurate of the two.

I was rather surprised to find only about 3 quasars in the image.

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

Related Designations for NGC4922

NGC4938

NGC 4938 is a barred spiral in northern Canes Venatici about 380 million light-years distant. It sits in front of a distant galaxy group about one and a half billion light-years distant. What drew my attention is that the southern part of the galaxy is much brighter than the northern though the features, if you ignore brightness, is rather symmetrical. It was discovered by John Herschel on February 17, 1831. I measure its diameter at about 88,000 light-years.

Also drawing my attention to this field is UGC 08168 near the top of my image. It appears to be the result of a collision of two galaxies as it has two red cores each with a huge plume or arm. To the west of the lower core is a huge blue star cloud. I suspect it was created by the collision but it may just be a third galaxy. I doubt that it is. This collision is unrelated to NGC 4938 being nearly 160 million light-years further away. It must be a spectacular sight for any beings much closer to it. The size of this train wreck is about 195,000 light-years including the plumes. I suspect the individual galaxies were less than half this size prior to their smash-up that scattered stars far and wide.

There appear to be two galaxy clusters listed in my field. Both are at a distance of about 1.5 billion light-years and contain lots of galaxies spread over a wide area. They do overlap. Could this just be one cluster but with Zwicky and Abell not agreeing as to the position of its core? Neither show a galaxy, large or small, at the center point of the clusters. The Zwicky cluster appears to be behind NGC 4938. One galaxy can be seen through NGC 4938 that is listed as being the Bright Cluster Galaxy for the small cluster of 23 galaxies. The cluster is listed as being 1.4 billion light-years distant though by some error the bright cluster galaxy is shown at a distance of only 380 million light-years, the same as NGC 4938. It can't be both a bright cluster galaxy and a tiny dwarf being eaten by NGC 4938. That Asian astronomer Sum Ting Wong seems to be involved here. He didn't stop there, however. Another galaxy just south of NGC 4938 is listed at the position of a 13 member group. The group is at 1.45 billion light-years while the galaxy is again at 38 million light-years. Both the bright galaxies at this 380 million light-year distance are listed as having their distance determined by the Friend of a Friend method. I don't understand this method. It appears they just assumed these are at the same distance of NGC 4938 and ignored others considering them members of more distant groups. I'd think this discrepancy would merit at least a mention at NED but I found nothing on it. I think it quite likely these small groups are parts of the larger Zwicky and Abell clusters.

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

Related Designations for NGC4938

NGC4939

NGC 4939 is another rarely seen face on spiral galaxy, about 160,000 light-years distant by redshift, located in southern Virgo about 5 degrees west of Spica and 6 degrees east of the far more well known Sombrero Galaxy, M104. It was discovered by William Herschel on March 25, 1786 and is in the second Herschel 400 Observing Program. It made my to-do list for both being a very lonely but disturbed looking face on spiral and for being on the that Herschel 400 list. At -10 degrees I need a very good night for it and this year those just didn't happen. Seeing turned awful right after I started the run but since I was sleeping I didn't know that until I went to process it.

I say it looks disturbed because in higher resolution images than I could achieve this night it is crossed by several very straight dark dust lanes. I'd hoped to pick up the stronger ones. Instead, two of the strongest blended together to make the vertical dark line just to the right of the core region. Problem is I also see hints of one to the left of the core that doesn't show on high-resolution images so has to be just noise. It could be the other one is also just noise in my image that happens to coincide with the location of the lane that really does exist there. I need a much better night though with so many good objects in this area still on my to-do list I can't see that happening any time soon.

While NED classifies NGC 4939 as SA(s)bc with a Seyfert 2 active core the de Vaucouleurs Atlas of Galaxy Types uses it as an example for a SAB(r)bc galaxy. That is having characteristics of both a spiral and barred spiral. Notes at NED also see a bar hidden in the bright reddish oval core region. The NGC Project, like NED, doesn't see a bar structure. At first glance the spiral arm structure looks rather normal for a wide open two arm spiral but on closer inspection it appears far more disorganized with the southernmost wide arm and the one inside it both coming off the same inner arm structure while the tighter arm fades away then reappears as the northern arm that doesn't begin to match the far southern going arm in structure nor match the angle of the arm it appears to be related to. The fade then reappearance of the arm at this odd angle gives the galaxy the appearance of being a three-armed spiral. Yet it is so lonely with nothing seen at its distance in the frame or for a wide area around it, it seems an unlikely candidate for having had an encounter that could account for this. Apparently, it is just natural for this somewhat peculiar galaxy.

NED lists only extremely distant galaxies so faint they barely show in my very poor data. For that reason, I didn't prepare an annotated image. Not only did the seeing go to bad a fog developed over my lake that raised my background level by a factor of 5 to 10 which would have required a lot more and shorter subs to have cut through. Since I was unaware of this that didn't happen. While the blue frames were taken before the fog but at the time of the worst seeing, I had a large discrepancy in star sizes for the color data. Green was so hit by fog only one frame was sort of usable. The other useless. Most of the green data for this one is pseudo green I created with my own technique leaving the color a bit suspect. That's the best I could do finding the problem now that the sun is in Virgo when I went to process the image. That made it impossible to get more data.

14" LX200R @ f/10, L=4x10' RB=2x10' G=1x10'+pseudo green to compensate, STL-11000XM, Paramount ME

Related Designations for NGC4939

NGC4958

The NGC 4958 galaxy group is a small group of galaxies in Virgo, 4 of which are in my image. All share a somewhat similar range of distances in mostly the 60 to 80 million light-year range. Though if you stick with just redshift or just non-redshift distance measurements they are somewhat scattered values with some having higher non-redshift distance and others higher redshift values. They may be outlying Virgo cluster members. I'm going to arbitrarily pick 70 million light-years as an approximate distance to all 4.

NGC 4958 is a rather red SB0 galaxy indicating little recent star formation. It was discovered by William Herschel on March 3, 1786 and is in the original Herschel 400 Observing Program. My entry for it from April 23, 1985 with my 10" f/5 scope reads: "Conditions poor with fog. Round nucleus with an oval halo. Center seems complex but seeing too poor to see much." I was going to revisit it but like my reimaging of objects I could have done better, that didn't happen either. Assuming the 70 million light-year distance it is about 115,000 light-years across.

The only other NGC galaxy in the frame is NGC 4948 which may or may not be IC 4156. It was discovered by Lewis Swift on May 25, 1897. Later DeLisle Stewart using an early Harvard image plate recorded 4 objects. There's nothing at the positions of any of them. These 4 were included in the IC catalog. With some assumptions about his error for objects he noted as extremely faint on this early plate the one for IC 4156 may be NGC 4948. The plate still exists but apparently, no one has gone back to examine it and determine what it shows. NGC 4948 is a rather red barred spiral classed as SBdm. There are some blue regions but mostly it is a rather dead galaxy like NGC 4958. It is about 43,000 light-years across.

The other two galaxies are listed as low surface brightness galaxies from the DDO catalog of low surface brightness galaxies. At the top of my image is DDO 163. It has bluer stars than the first two galaxies. It too is about 43,000 light-years across but its a much fainter galaxy.

At the bottom of the image is DDO 162. It is somewhat brighter than DDO 163 but smaller being only 26,000 light-years across. It is often listed as NGC 4958A though not in the NGC. It's the bluest of the bunch and appears to be a rather active galaxy.

Only one other galaxy in the image had redshift data at NED but it lies some 1.19 billion light-years away so is unrelated to the other 4. While there are a lot of other galaxies in the image I couldn't find much on them. I'd not have prepared an annotated image but there were some very faintly seen asteroids in the frame so I did prepare one to help you find them. Since I did I included a few brighter galaxies without redshift data as well as one very low surface brightness galaxy listed in NED as simply a Uv Source with its GALEX coordinates for an ID. NED doesn't even list it as being a galaxy though it obviously is one. NED lists several dozen more as IR sources from the 2-micron survey that I didn't bother to annotate. A handful carry extended PGC designations NED doesn't carry. When I asked several years ago why they said it was too unreliable and all are covered by other catalogs they do carry. Since many catalogs they carry duplicate others I'm not sure I understand that explanation. This was many years ago, maybe I should try again and see if that opinion has changed.

The night I took this image was very poor. Clouds were constantly blocking the view. Notice the asteroid trails are much fainter than normal for their magnitude and fade in and out, vanishing totally at times. Things got so bad one green frame was virtually lost to clouds. Only about 6 stars can be seen plus the core of NGC 4958. I had to throw that frame out. My color balance is a bit suspect thanks to these clouds but appears about right. There were several other asteroids in the frame that would normally have been seen but due to conditions were not visible even in the FITS files no matter how hard I stretched them. If I relied on guiding I'd have lost the guide star many times resulting in not one usable frame. Another reason why, if the mount can do it taking the time to set it up for unguided imaging can pay big dividends, especially when running under automation.

14" LX200R @ f/10, L=4x10' RB=2x10' G=1x10', STL-11000XM, Paramount ME

Related Designations for NGC4958

NGC5002

NGC 5002 is a barred Magellanic galaxy usually considered a member of the NGC 5033 group in Canes Venatici. NED's 5 year WMAP data shows it to be about 61 million light-years distant though a single Tully-Fisher measurement puts it about 40 million light-years distant. That's the distance APOD puts on NGC 5033 so I'll use it rather than the redshift-distance which is likely distorted by its motions in the group. That makes it about 20,000 light-years in diameter, rather typical for a galaxy of its type. I assume the bar is the linear structure. Odd in that it runs from the core to the edge on one side but not the other so is it a half barred galaxy? A loop of star knots runs through the galaxy. In lower resolution images it looks quite different than in my image. Then there's kkh 081 a very faint irregular galaxy at about the same redshift as NGC 5002. They may be traveling together and thus it is really about 40 million light-years distant same as NGC 5002. When I first brought up the luminance stack I thought it a faint reflection and nearly processed it out. But when I checked Jim Thommes recent image of the area I saw a very faint hint of it then found it very faintly on the POSS plates and Sloan image. There it appeared very "grainy" as it does in my image. Comparing the two the grain pretty much matches indicating the galaxy really is grainy, that is composed of faint star clouds. This is one that deserves a lot more time to see if this goes away or gets stronger. NGC 5002 was discovered by Heinrich d'Arrest on April 27, 1865.

In preparing the annotated image I came across two galaxies from the TONS12 catalog. I'd never heard of it. That stands for the Texas-Oxford NVSS Structure 12 hour region catalog. NVSS is a radio catalog by the National Very Large Array. That's the NV part, SS stands simply for Sky Survey. How Texas-Oxford fits in I don't know. Anyway, those two are radio galaxies, one, a lone distant but very bright and compact galaxy the other the bright cluster galaxy anchoring a 12 galaxy cluster in the upper right corner of my image. The distance to the cluster has been calculated photographically not spectroscopically, hence the "p" designation. The "est" for the galaxy means it is an estimate. Now how this is done I have no idea. In any case, it means both are likely less accurate than a spectroscopically determined distance.

One faint asteroid is listed in the annotated image. Details are in that image. You may need to enlarge the image to see it as it barely registered. The lack of a number indicates it has yet to complete one orbit since its discovery.

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

Related Designations for NGC5002

NGC5005

NGC 5005 is a bright spiral galaxy in Canes Venatici that's about 54 million light-years distant by redshift and 55 million by Tully Fisher measurements. A surprisingly close agreement. It is considered by some to be a companion to the much more famous, highly warped galaxy, NGC 5033 about 41 minutes to the southeast and thus out of my frame. NED classes NGC 5005 as SAB(rs)bc;Sy2 LINER while the NGC Project says, Sb (no bar). Most notes at NED refer to the bar saying it is offset from the major axis by 30 degrees. I see no hint of it visually. This is likely why the NGC Project doesn't recognize it. It seems rather dust red reddened. Is it the cause of NGC 5033's warp? It seems too normal for that. NGC 5033 has two satellite galaxies that might be a more likely candidate though it could be due to a galaxy it ate and no longer exists.

It was discovered by William Herschel on May 1, 1785. It is in the original H400 program. My entry dated April 28, 1984 with a 12.5" f/5 using up to 150x on a great desert night reads: "Stellar nucleus. Easy dust lane with faint outlying arms. Fairly bright. Good object but the arms weren't seen in my 10" scope."

Above NGC 5005 is the dwarf irregular galaxy LEDA 166157. I couldn't find much more than this about this obviously very blue, low surface brightness galaxy. It did make the Karachentseva and Karachenstev list of new nearby dwarf galaxy candidates. http://aas.aanda.org/articles/aas/pdf/1998/03/ds6146.pdf The distances to some entries were later estimated but not for entry 188 which is LEDA 166157 unfortunately. There is a newer paper on these by the same authors but it is behind a paywall so I didn't investigate further. http://cdsbib.u-strasbg.fr/cgi-bin/cdsbib?2007AstL...33..512K

As with much of the year, the weather took its toll on the image. The blue frames were very bright with a background twice that of red and green. That is very unusual. Again, I was sleeping while this data was taken so I don't know what caused the problem. Even after all my color balance tricks, the galaxy doesn't quite look right to me as to color. Might just be due to below average seeing. Certainly, the luminance frames didn't go nearly as deep as usual coming up a good magnitude short of normal skies.

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

Related Designations for NGC5005

NGC5012A

Usually, it is the major NGC galaxy I'm featuring not its sidekick. In this case, the sidekick is NGC 5012A. Probably a better name would be UGC 08290 or PGC 45884. It is what I call a "sloshed" galaxy. This is in the sense of how the yoke of a fried egg can be moved off center by moving the frypan before it sets. The galaxy's core is far off-center. That's certainly the case with this galaxy. Sometimes you can see the other half of the galaxy is there, just very faint due to a lack of bright stars. NGC 5474 near M101 is an example. In its case, it is thought its interaction with M101 caused the "sloshed" effect. You can see the rest of it faintly in my image of it. But with NGC 5012A I see no hint of the "other side". Also, NGC 5012 doesn't appear distorted enough to have had a serious gravitational interaction with it. They are at about the same distance by redshift, 130 million light-years away.

I found little on this pair. Certainly, nothing indicating any interaction. One old (1970's paper) denied interaction. Something sloshed NGC 5012A, but what? It is classified as Sm: by NED and pec? by Seligman. I couldn't find who discovered it or when. NGC 5012 is classified as SAB(rs)c LINER by NED and SBc? by Seligman. It was discovered by William Herschel on April 10, 1785. It is in the second H400 program. My log from that was lost in the move to Minnesota so I don't know if I also saw NGC 5012A. Considering that was over 30 years ago my memory is of no help.

This is one of my very early images from 2007. Even the FITS were so poor I gave up trying to rework it. I need to go back to the original FITS files to do it justice. My processing abilities were nill back then and my software limited. For instance, there's a hint of a pair of interacting galaxies just above NGC 5012A (NGP9 F379-0539970 at about 870 million light-years) but my ham-handed processing has destroyed much of the detail. I think there's a plume from the larger eastern one. But I have to either retake this or reprocess the data to know for sure. I couldn't find any deep images of this field on the net. Until I can research this one better this will have to do.

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

Related Designations for NGC5012A

NGC5014

NGC 5014 caught my eye due to its odd dust lane. Near edge-on spiral galaxies have dust lanes that go down their length bisecting the galaxy. Though those lacking dust may not show a dust lane at all. But this one has a dust lane that goes vertically through the galaxy west of the core. By some fantastic coincidence, two field stars from our galaxy mark the endpoints of this dust lane. Both the stars and the dust lane are rather a rather similar shade of red as well. I did tone them down quite a bit as otherwise, they overpowered the dust lane. I did this equally so their relative brightness difference is maintained. There is a short dust lane below the core more where one should be. Seeing wasn't up to snuff, nor was transparency. The core has a blue blob on its east side according to the SLOAN image but it was below my resolution level.

There is a small plume above and a bit left of the core that is rather blue compared to the rest of the galaxy. Could this plume be due to something it digested recently? If so that may also explain the odd dust lane as due to the interaction or merger.

Redshift puts the galaxy some 63 million light-years distant while non-redshift measurements put it a bit closer, say 56 million light-years. Using the latter distance I measure its size at 32,000 light-years. Not a large galaxy. NED classifies it as Sa? as does Seligman. It was discovered by William Herschel on May 1, 1785, though he got its position a bit wrong as did his son years later. Still, with nothing similar in the area, its identity is quite certain. As it is rather faint it isn't in either of the Herschel 400 observing programs even though it is well positioned for northern observers in Canes Venatici.

The field contains the usual assortment of distant galaxies and quasars as well as a small galaxy group known as SHK 248. As I'm starting to go through this catalog by Romelia Shakbazian for interesting groups such as this one I was pleasantly surprised to find one of her groups in the image. So I went to Google to find out more. That gave me an all too often result. The only citations it came up with of other than papers discussing the entire catalog were mine from two years ago. https://www.cloudynights.com/topic/405703-back-to-obscure-satellite-galaxies-holmberg-viii/

I won't repeat what I said there but can add a bit. The count is 9 galaxies according to NED. One has an identity problem discussed in the above link. Another SHK 248:[STC97b] 04 in my annotated image is actually two very close galaxies. Neither time was seeing sufficient to split them, unfortunately. But I can't get 9 galaxies. By definition of SHK groups, all should be easily within my grasp but I only get 6 or possibly 7 if ASK 519408 is included (see the link for more on this. There are three objects in a line at the top of the group but only the middle, slightly blue one, is a galaxy, the other two are stars. Also, the bright orange object at the end of a curving chain starting from the double galaxy is just a star. So where are the other two or three members? All I can come up with is that she mistook the aforementioned stars as galaxies. Easy to do working from the POSS plates rather low resolution.

In case you are wondering here are the requirements for inclusion in her galaxy group catalog:

*They must contain 5–15 member galaxies.

*Each galaxy's apparent magnitude in the POSS red band must be comprised between 14m/19m.

*They are compact, id est the relative distances of the member galaxies are typically only 3/5 times the characteristic diameter of a member galaxy.

*Almost all galaxies must be extremely red; there must not be more than one or two blue galaxies.

*Galaxies are compact (high surface brightness and border not diffuse).

*The group must be isolated.

I'm not sure this one meets the red galaxy requirement. The northern member is blue as are the easternmost two in the bottom curve along with the one nearest the double galaxy. They too are somewhat blue or at least not all that red. That makes me think she included the three red stars as galaxies bringing the count up to 9 if the questionable one is included and the double is listed as single. The clusters were identified from the red POSS I plates which didn't have the resolution to split the double galaxy so I suspect it counts as only 1.

As an extra bonus, it turns out my 2012 image of the galaxy group could be easily combined with this image to make a much wider field. Its main target was Holmberg VIII from when I was taking the Holmberg galaxies. So I made a hasty combine of the two. This makes for a larger than normal image but is a nice one. Since conditions were quite different and my processing software has changed some I really should have processed the older image to be a better match. So don't look too hard for the seam as the change in signal to noise ratio is rather obvious thanks to the poorer transparency this spring.

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

Related Designations for NGC5014