GAL201.6+01.6

LBN 902 and GAL 201.6+01.6 swimming in the dark nebula LDN 1608. These are located northwest of the Fox Fur Nebula, NGC 2264 in the constellation of Monoceros. The entire area is full of HII, reflection and dark nebula. I find no distance estimate for it and the estimates of the many nebulae in the area vary from 1000 to 8000 light-years so that is of no help. It appears to be a combination reflection (blue part) and emission (red) nebula somewhat separated from the general HII emission of the area by the dark nebula LDN 1608. I suspect it more likely related to the dark nebula than the general emission nebula of the area and thus likely in front of the emission nebula.

I have no idea why I imaged this one. I left no notes and find nothing much on it in the literature. There are many far better nebulae in the area. I must have had a reason. I just don't know what it was!

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

Related Designations for GAL201.6+01.6

GN05

Magakian 104/GN 05.28.8 is a beautiful blue reflection nebula in the larger nebula of Ced 51 that gets nowhere near the respect it deserves. It is in the head of Orion. Apparently, it is lost due to the other showpieces in that constellation. I can't find much on it at all.

My image was hurt by a haze that varied from thin to rather thick robbing me of lots of photons and creating large halos around stars as well as fuzzing detail. Blue was especially hard hit with large halos around even red stars. Removing them was nearly impossible and took far more time than the image is worth. But with my horrid 2012 conditions that is the norm it seems. I'm getting to be a broken record on the subject. It's frustrating spending several hours more to process an image simply because of what the weather did to my data.

The small dark nebula in the red emission nebula at the top of the image is LDN 1584. Out of the frame at the top is the much larger and darker Barnard 32. The entire field including Barnard 32 can be seen at http://www.astrobin.com/30585/B/ . The image is mirror flipped with east on the right instead of the left. I hope that doesn't bother you as much as it does me. It was taken under far better Arizona skies.

If you have very good eyesight you might see the asteroid (232412) 2003 EL3 near the top right of the image. It isn't very bright at Magnitude 19.4. Even fainter and harder to find is (207288) 2005 GJ14 near the top left of center at magnitude 20.5. Quite a few galaxies are in the image but not a single one is listed by either NED or SIMBAD. So I never made an annotated image.

14" LX200R@ f/10, L=4x10' RGB=2x10' through varying haze and lots of green/brown airglow, STL-11000XM, Paramount ME

Related Designations for GN05

GN20.16.3.02

GN 20.16.3.02 is a small reflection nebula surrounded by the much larger DB 82/IC1318A. The field is located in Cygnus about 1.8 degrees northeast of Sadr I couldn't find anything on the reflection nebula, not even a distance estimate. Most put the nebula associated with Sadr at 2000 to 5000 light-years. But how the reflection nebula relates to the HII region isn't mentioned. I suspect the reflection nebula is due to a bright star embedded within the HII region.

There is a dark nebula or patch southwest of the reflection nebula. I wasn't able to find it in any catalog though it is quite obvious. Less obvious is the much larger dark area to the NE of the reflection nebula just beyond the edge of the brighter red nebulosity. It is rather round with a bright blue star seen against it. It is DOBASHI 2453. Just above it is a larger dark region which is DOBASHI 2465. On my right edge is a line of 4 bright stars with a scattering of fainter ones behind the group. This is the open star cluster [FSR2007] 0226.

My limited field doesn't begin to see all of IC 1318A. For that see Jim Thommes excellent wide-field view of the nebula at http://jthommes.com/Astro/IC1318NW.htm . His image uses a lot of HII data which I didn't take. His annotated image shows a lot of the identifications of the bright nebula within IC 1318A.

This is yet another severely smoke damaged images. I took the green data when a denser cloud went over so it was very weak. I was able to use only one of the green frames and it was much weaker than the blue filter. Blue was hit too hard for eXcalibrator to salvage so I had to sort of fake the blue then use it to help the green. That means my color is very highly suspect but at least it looks fairly good. Also, the smoke caused some severe halos around all but the redder stars. I spent most of a day dealing with the halos. Oddly they weren't seen in the RGB frames but were in all luminance frames. After taking the luminance I had to stop as the smoke was too thick for even the red filter. After an hour it cleared enough to take the color frames but hit again when taking the green data. By then I was in bed and didn't know it was clobbered. This one may be worth revisiting once the clouds and smoke go away. New fire in California is sending more smoke my way. Last I heard it had zero containment. It started well after this object was taken but means once the clouds clear I'm still likely seeing smoke.

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

Rick

Related Designations for GN20.16.3.02

GN21

This field is located less than a degree north-northeast of Sh2-120 and Sh2-121. The night allowed me to pick up the general H alpha glow of this part of Cygnus north of the North American Nebula. The field is a nice mix of light and dark nebulae and is an area of newly forming stars judging by all the Y*Os in the field (Young Stellar Objects -- that is, stars still coming out of their dust cocoons and moving onto the main sequence where they will spend most of their lives as ordinary stars).

While I've identified some of the Y*Os in the image it is only a few of them. Labels on top of labels would have been the result in some areas had I tried to cover them all. I gave a taste of how many could crowd in an area around LBN 408 near the top of the image.

There's an object down toward the bottom right of the image that makes a sort of squashed ring. I was unable to identify it. A piece around a red star was GN 21.00.7. A condensation to the west of this is MHO 958 an emission object. A very faint, difficult to see speck to the left of GN 21.00.7 is HH 1051. There are a dozen more HH (Harbig Haro objects) in the image, all such faint specks I didn't bother to point them out, many more were below my exposure time to even detect. But what that ring itself is I couldn't find out. Others have identified it as GN 21.00.7 but that just doesn't fit unless the GN designation is for the "illuminating star" and it is a reflection nebula. That doesn't seem to fit other GN objects however unless they are vdB objects which this is not. I'm not well versed in identifying these objects so if someone has the answer please let me know.

There's an interesting HH object (HH 389) just to the northwest of this field that I took in November. It was taken on a better night so goes a bit deeper. I considered mosaicing all three (including Sh2-120-1) but the nights were so different as to transparency it would be very difficult to get it to work so I gave up that idea. Turns out there's a lot of interesting stuff for a high resolution system in this part of the sky normally imaged with wide angle systems. Those wide field images make a nice set of "survey plates" for me to find these small objects.

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

Related Designations for GN21

HANNYS VOORWERP

As you've probably noticed I like imaging things few others do. This one certainly falls into that category. Not only that it was just discovered last year. It appears unique in the universe. At least we know of nothing like it anyplace in the universe. Or so we thought when I wrote this -- I've since imaged two others. It is known simply as Hanny's Voorwerp. If you put voorwerp into a Dutch English dictionary it will tell you it means "object". But to those studying this voorwerp a more correct translation would be "What the #$(* is this?". Also, who is Hanny? The story is long so those that already know it can skip to the image. The rest of you might find the saga rather interesting.

First I need to explain Galaxy Zoo. You have noticed how many uncataloged galaxies lurk in my images. Galaxy Zoo is part of a project to remedy this using the help of anyone interested in astronomy. It is attempting to classify these faint fuzzies. They are sending out images of them to folks like you to determine if they are an elliptical, spiral or irregular galaxy and if spiral, do they spin clockwise or counterclockwise. The latter had some surprises though more to do with psychology than galaxies. The project has expanded greatly since I first wrote this. Anyway, Hanny is Hanny van Arkel a preschool teacher in the Netherlands. One of the "galaxies" selected for her to categorize was this one. These are sent to several and only when all or most agree is the category accepted. In this case, only Hanny thought something odd. She posted a note to the galaxy zoo forum asking others to look at her mystery. All told her to contact the bigwigs running the project but one of the moderators jumped in and soon things got really interesting. Only recently has a possible solution to this mystery been proposed that seems possible.

But I need to go into why this was such a mystery. First off Hanny's Voorwerp is bright green. This is a rare color in the universe. Stars can't be green due to the way our eyes see color and how quantum physics works. Ionized oxygen can as can ionized hydrogen in one wavelength but normally if that wavelength is present the red one is even more obvious and we see the object as pink not green. Her voorwerp is the size of a galaxy yet contains only dust and gas, no stars can be found in it even at infrared wavelengths which should turn up stars in thick dust and gas. It is the only galaxy sized intergalactic cloud of ionized gas known. But where do you get the energy to ionize it? It is estimated you'd need the energy of billions of stars far hotter than our sun to do the job and they'd have to be right at its surface. Here you have something giving off as much energy as an entire galaxy but at odd wavelengths that turn it green that contains NO energy source. YIKES. This is magic, not science.

First thought was that the nearby galaxy IC 2497 may have had its black hole eat something huge about 100,000 years ago and that turned it super bright. That light then hit this huge gas cloud and due to geometry that reflected light is just now reaching us. Such light echoes are known but this one is very bright and again, the illuminating light couldn't be green. Nor would it likely have the ultraviolet energy needed to ionize it like we see here.

So why is it green. It turns out most of the light it emits is OIII and H-beta emission but no Halpha to speak of. Normal ultraviolet light can't make strong Hbeta and weak Halpha. Physics just doesn't allow this. The current best guess is that a few hundred thousand years ago the galaxy passed through a small cluster of galaxies out of my image frame. In doing so it was stripped of nearly all its dust and gas which then formed as a galaxy sized cloud far outside the galaxy. In the meanwhile star orbits in the galaxy were shaken up and some fell into the black hole that is thought to lurk in the center of most galaxies. We can't see it as it is deep inside the galaxy. Radio telescope data shows an intense beam of radiation (high-energy particles not light) is being beamed from the center of the galaxy right toward Hanny's Voorwerp. Also, these scopes show a far larger cloud of hydrogen gas of which Hanny's Voorwerp is just a small part, the part this particle beam hits. A beam of high-energy particles can create this green cloud if its composition is right as apparently, this one is. But only the side of the cloud facing the beam is lit. Most are shielded by the glowing gas. We see only the parts where the cloud is thin enough that we can see the lit portion. This explains the light and dark regions we see. As a side note, Hanny was invited to the radio observatories that may have solved the mystery to participate in the release of their research.

A lot more work needs to be done to pin this all down, however. So stay tuned. It will also be interesting if the voorwerp changes its shape and brightness with time. As the particle beam is blocked by possible clouds still in the galaxy it could change rapidly much as the far smaller variable nebula in our galaxy such as McNeil's Nebula I featured a few updates back. Here are a couple links you might find interesting.
http://www.astr.ua.edu/keel/research/voorwerp.html
http://www.universetoday.com/2008/11/25/hannys-voorwerp-revealed/

The photo with the second link was taken with the William Herschel Telescope which is far larger than my house and one of the worlds major scopes. You can compare it to my efforts.

Since I wrote the above in 2008 more has been learned. Here's what I said in 2011.

Finally, two years later Hubble investigates this mystery cloud of green gas near IC 2497. It turns out to be OIII emission from gas left over when the IC 2497 tore apart a passing galaxy. The cloud is far larger than seen in visual light. The interaction fed the galaxy's black hole. This, in turn, lit up the black hole, much of the light being blocked by infalling dust and debris. The high-energy UV light that did escape in one area lit up a small part of the cloud causing the OIII to glow its green color. I see no explanation of why H alpha emission, normally seen when OIII is present, is not seen in this case.

The black hole is now "sleeping" and no longer emitting much light. But since the path from the cloud to us is hundreds of thousands of light-years longer than the direct path from the black hole to us we are seeing a light echo from the black hole. Same as we hear a sound echo long after the source of the sound has stopped. The diagram of the path of the passing galaxy that left the debris cloud shows the arrow ending about the location of a small very blue galaxy immediately east (left) of the main galaxy seen on my image and Hubble's IR image. The latter shows it to be far larger as seen in IR light than in visual light. Is this the galaxy that left the material making up the green cloud? Again, the article doesn't seem to say. Though probably not. It's likely the galaxy that left the cloud is now part of IC 2497. In other words, they merged. This would explain the debris cloud mostly hiding the black hole that lit up a part of the cloud. Though the arrow in their diagram doesn't show this the text does indicate a merger is likely. I just wish the text was clearer on this.

HST visual image and story
http://hubblesite.org/image/2803/news_release/2011-01

HST IR image
http://hubblesite.org/image/2805/news_release/2011-01

Diagram
http://hubblesite.org/image/2806/news_release/2011-01

IC 2797 is listed by NED at 660 million light years light travel time though I've seen other estimates putting it at 800 million. The edge on galaxy in the full image is LEDA 090934 at 621 million light years per NED. I've attached two versions. First is a 2x crop of the Voorwerp and the second the full frame.

In 2015 I imaged two more galaxies with green voorwerp like features. See my posts for NGC 5252, NGC 5972 and UGC 11185 for two more of these very rare objects. Here's an article on these two and the others discovered so far: http://www.skyandtelescope.com/astronomy-news/hubble-finds-ghosts-of-quasars-past-042215234/

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

Related Designations for HANNYS VOORWERP

HCG051

HCG 051 is a group of 7 galaxies in northwestern Leo. The two brightest galaxies are NGC 3651 and NGC 3653 both discovered by William Herschel on April 10, 1785. A third galaxy is IC 2759. It wasn't discovered until over 100 years later by Guillaume Bigourdan on April 24, 1897. The others apparently escaped discovery until after Dreyer had finished the NGC and its IC entries. I have nothing on their discovery. Hickson published his list of 100 groups in 1982. With 7 rather large and bright members it is one of the richer groups on his list yet not all that well known.

HCG 51F, aka PGC 034899 is the strange galaxy of the group showing either a very sloshed core drawn to NGC 3651 or a plume. I found nothing on it to decide the issue. Another possibility is that it is entirely normal and the northern half is just lost in the stars of NGC 3651. It's disk stars are a bit bluer than those of NGC 3651 so I'd have expected them to stand out thanks to the color difference but I don't see that either in my image or the Sloan survey image. I found no other images online to help here.

In the upper right corner is the galaxy PGC 034804. NED classifies it as an Irregular galaxy. To me it is an obvious two arm rather open spiral galaxy. Say an Sb or there about. Thus I added "??" after NED's classification. It, like many in the image, appears to be a member of the same group as the HCG 051 galaxies. Just a much smaller member than the main ones making up the group itself.

The Minor Planet Center reported 2 asteroids in the image. I can only find the fainter one. Its trail is very short and is at 20.4 magnitude by the Minor Planet Center's estimate. the other is 20.0 by their estimate but its track is similarly short and entirely within ASK 624844.0. Being brighter I was unable to find the asteroid. The one I could find is lost in the annotated image but is due south of the HGC group below the densest section of the annotated image.

This brings up a problem I had annotating it. Normally I just ask NED and Adladin to mark those in my frame with redshift data and I annotate those. Sometimes one or two are too faint but that's rare unless my night was poor. Sometimes this results in only a few galaxies, with 25 to 40 being normal and once in a while up to 100. But when I did that for this field I about had heart failure. It returned 12,892 galaxies. The result was an image nearly totally white with marked galaxies. What happened? I was sure something was wrong so got the data for one and checked my image. It was there. Then another and another with the same result. Then I tried another that was marked as being taken with a red filter. My camera is very insensitive in deep red. It wasn't there yet at magnitude 21.1 was brighter than a green one of 22.5 magnitude I easily saw. Then I noticed that almost all of the "extra" galaxies came from a catalog I'd not heard of the RCS catalog. That stands for "Red-sequence Cluster Survey" I suppose that explains all the red photometric magnitudes. All from that catalog had photometric redshift calculations rather than spectroscopic I was used to in most cases. These are much cheaper to obtain in bulk but not as accurate. Still, they usually give a reasonable estimate. As usual, those are noted with a "p" after the look-back time distance.

Now I had a problem how to annotate these. In the 5' center of the image (not the center of the cluster but close), I chose to annotate those brighter than 21.0 magnitude. I soon came to realize this was not going to work. I downloaded all 12892 entries into a text file then sorted out those dimmer or equal to 21.0. That left a huge file. I didn't try to count them but over 1000 I'm sure. No way that was going to work so I dropped my limit to 19.99 or brighter. That left me about 140. I gulped and dove in. I didn't have the aids I normally have as I never figured out how to limit NED and Aladin to my 19.99 limit so had to find them the hard way. Took some 5 hours. I've got to find a better solution if that RCS catalog is now widespread in NED. I've not had time to go check. But thanks to its photometric distance data hundreds of SDSS and 2Micron galaxies that had no redshift now do. I suppose one answer is to eliminate all NED notes as being photometrically determined. That would put me back to where I was before but since I can't, as yet, find a way to filter Aladin to do that I'll still be doing it the hard way.

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

Related Designations for HCG051

HCG061

The HCG 61 galaxy group is one of Hickson's most photogenic being composed of four bright, NGC galaxies arranged in a rectangle. This has given it its common name of "The Box". It is composed of NGC 4169, NGC 4173, NGC 4174 and NGC 4175. All but NGC 4173 are located about 200 million light-years from us. NGC 4173 is located only about 65 million light-years away by redshift though there's a good agreement that its non-redshift distance is only 30 million light-years. The group is located in northwestern Coma Berenices.

I measure NGC 4169 with a diameter of 135,000 light-years making it the largest of the group. NGC 4174 is the smallest at only 53,000 light-years while I measure NGC 4175 at 110,000 light-years. While appearing much larger, NGC 4173 is also much closer. I measure it, including the long arm to the southeast as being 84,000 or 39,000 light-years in size. If the closer distance is right it is the smallest of the four. At the time of Hickson's catalog distances to most of his galaxies was unknown. He was working on appearance, well aware that this isn't going to always equate to distance. Hence his name for them of Compact Groups. He didn't mean they really were compact, only that they appeared that way from our vantage point. Also, if you look around the annotated image you will find a few other galaxies also with a redshift of about 200 million light-years that are likely true members of the group but don't meet Hickson's requirements so aren't included in the group. What I do find odd is that when I ask NED for HCG 61 it says it has 3 galaxies, not four but then when asked individually about the four gives them the HCG letters A through D I show in the annotated image. I've found this count difference many times in NED. I suppose I should ask them about it but so far haven't done so.

This image had something go wrong. I still have no idea what but the left side of the image is way out of focus. If this were due to camera tilt (which has happened to me) the stars would elongate but these turned into donuts with a bit of distortion due to being at the edge of the field. All subs showed the same error. It was taken the same night as NGC 2742 and NGC 3686. It was taken between these two yet neither show this problem. I've not looked at all taken since but none I have looked at show this issue. I'm stumped as to what could cause it. Since that put the Abell 1495 galaxy cluster well out of focus I have this one on the reshoot list.

Just off the southwest end of NGC 4174 is ASK 574454.0 which NED lists as a candidate dwarf but if its redshift distance of 1.08 billion light-years is correct I measure it as being the same size as NGC 4174 which is a normal sized S0 galaxy. I suspect it got the possible dwarf label before its distance was known. But why that hangs on I find interesting, inertia?

There's a pair of interacting galaxies near the bottom center of the image, KISSBx 37. I couldn't find them listed separately. NED normally labels distance data as p for photographic, Spec as proven spectroscopic measurements. If likely spectroscopic but not proven it leaves that blank. For this one, however, they use the label ? which I've never seen before. I don't know what they mean by it but included it in the annotation. I can't prove these two are interacting but they sure appear to be interacting.

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

Related Designations for HCG061

HCG067

Hickson scoured the POSS plates and cataloged small compact groups of galaxies. One I found very interesting is #67 in the list. Interesting because Hickson and others got it wrong it appears! Probably because most work from the POSS plates which overexposed the core galaxy of the group hiding its true nature.

The group consists of two major galaxies, NGC 5306/VV135 and MCG -01-35-013. MCG -01-35-013 is a nice edge on, somewhat distorted, spiral. The southern arm is rather odd. The dust lane ends and suddenly the arm gets very narrow and blue. The transition is very sudden and unusual. The galaxy has not been studied that I could find.

NGC 5306 is where things go wrong. By all catalogs, NGC 5306 is the center "galaxy" with two others, north and south of it, not considered part of NGC 5306. The Vorontsov-Velyaminov Interacting Galaxies catalog, however, does include the galaxies to the northeast and southwest as they reside in a common halo. But all catalogs miss the fact that the core galaxy is actually two galaxies. NED doesn't show them separately nor does any catalog I could find. On the POSS 2 plates, they merge into one due to overexposure. Apparently, no one looked further. The VV catalog lists the pair as VV 135a as I've shown in the annotated image. The other two being c and b of course. NED classes NGC 5306/VV 135a as either S0 pec or E1. The NGC project says S0P? The redshift value like their classification is apparently a mash-up of that for both galaxies.

This field was recommended to me by Sakib Rasool so I contacted him to ask if he wanted me to image it because he suspected that NGC 5306/VV135 was a double galaxy. Nope, it came as a surprise to him as well--he's not easy to surprise. He was interested the spiral MCG -01-35-013 as it appeared warped or distorted on the POSS plates. After my email, he did some digging and contacted the astronomer John Hibbard, who studies interacting galaxies. Dr. Hibbard then did some digging and came up with one paper on it I'd not found. http://aas.aanda.org/index.php?option=com_article&access=doi&doi=10.1051/aas:1999513&Itemid=129

The paper labels it a double core galaxy; n1 and n2 which I labeled on the annotated image. But it goes on to indicate the authors feel these are two superimposed galaxies not as close as their angular separation indicates. I would agree with this as while the overall halo is oriented toward VV135b and VV135c, n2 is oriented almost at right angles to this. Oddly it is the brighter of the two, however. This would need some explanation it would seem. This is one group that needs a lot more study and some catalog asterisks or corrections.

VV 135b is classed as S0 pec. I don't know what causes them to tack on the peculiar label. VV 135c is classed Scd. It sure has some odd structure to it. Unfortunately, the structure is beyond my abilities to determine what it is. It certainly looks disturbed but somehow avoided the pec label.

A few other galaxies are scattered across the image that are members of the same group as HCG 67. Others are about twice as distant. The field is little studied with most galaxies being anonymous.

While the image is my usual size in pixel count it was taken at 0.5" per pixel rather than my normal 1" per pixel so covers only one-fourth the area of my normal images. As such, most of the remaining members of the group containing HCG 67 lie beyond the field of view. If I'd used my normal field it would have made a 4 times bigger image and too big for the Internet. Though now I wish I'd have taken the full field and reduced it to my normal scale of 1" per pixel, I'd have picked up almost a dozen other members of the group. I can't find any catalog entry for the entire group, just pieces of it. It is rather widely scattered. I was hoping to bring out a jet that one source says is coming from the nucleus of NGC 5306 but I don't see it. How they find such a jet yet miss it is a double galaxy I can't understand. I'm wondering if the "Jet" is really N2 sticking out of the overexposed blob they both make on the POSS 2 plates. Since it is already at a greater image scale than my normal cropped images I've not done one this time, just a cropped version for those who complain my images are too big.

Dr. Hibbard's email goes on to say about Hickson 67: "It appears to be the central concentration of a larger group with at least 15-17 members. About 10-15% of HCGs are thought to be such creates, and thus not true compact groups in the way Hickson meant.

"These double nucleated ellipticals are interested - they are sometimes considered examples of galactic "cannibalization". About 25% of cD galaxies have multiple nuclei (although I am not sure if NGC5306 is a full-blown cD; that requires it to have an extended luminous envelope). See e.g. http://ned.ipac.caltech.edu/level5/March02/Sarazin/Sarazin2_10.html.

"Well, back to work. Thanks for the diversion and beautiful image!"

For a bit there I thought I might have found something previously unknown. Nope, just something hidden deep in the literature. Still, finding something this obscure is quite exciting.

14" LX200R @ f/10, L=8x10'x1 RGB=2x10x2', STL-11000XM, Paramount ME

Related Designations for HCG067

HCG068

Hickson 68 is a galaxy group far larger than apparently Hickson realized. He made the catalog from visual inspection of the Palomar Observatory Survey Plates of the 1950's creating a catalog known as the Hickson Compact Group catalog. Well HCG 68 is not compact. He apparently was only considering the core region. The group is really far larger than my image. It is organized with elliptical galaxies in the center and spiral galaxies mostly on the edges many of which are beyond my FOV. The large spiral NGC 5390 is an example as is UGC 8841 in the lower left corner of my image. The group is located about 115 million light-years away in the constellation of Canes Venatici.

The center is home to the overlapping galaxies NGC 5353 and NGC 5354 which inhabit a common halo. NGC 5353 is an S0 galaxy rather than elliptical that harbors a rather active AGN indicating this might not be a serene old group like it first appears. NGC 5354 to its north is Classes SA0 with strong spectral lines and is a LINER galaxy. Yet more indication this is an active group still in its formative stage. Then there's NGC 5350 a rather classic looking barred spiral. NED classes it SB(r)b while the NGC project says SBb-c. It is a starburst galaxy with intense star formation going on in its core that is hidden from our view by warm dust. Yet another indication of activity.

Other NGC members of the group include NGC 5355, an E3 galaxy by NED and S0? by the NGC Project. NGC 5358 is classed SO/a by both. The other large member of the group in my image is UGC 08841 which is a very nice two armed barred spiral classed by NED as SBb.

NGC 5353 and NGC 5354 appear to share a common halo. It has a very weird sharp cut off at its southern end and appears slightly brighter right before it comes to that sudden end. This is often seen when a dark nebula abuts a bright nebula forming a shock front. I scoured the literature but found nothing addressing this odd feature. Closest I came was an article talking about how this is a still collapsing system with lots of activity to come over the next billion years. http://iopscience.iop.org/1538-3881/135/4/1488/pdf/aj_135_4_1488.pdf

This image is a complete reprocess from the very beginning of data taken back in 2008. When I processed it I included both color and luminance frames taken though clouds which cast a strong gradient across the image, While it was removed much of the halo, including the sharply defined southern end were gone. I through out all these frames and ended up with a much better image that now shows the halo's sudden southern end. Since the color data is weak I am a bit leery of it in faint regions like this halo. If it is right (a very big IF) then the plume has an odd red color as it comes to a halt. This is very weird if true. Is it really gas and dust ejected from the two massive S0 galaxies rather than stars? When galaxies of this size interact most dust and gas is ejected. Is that the source of the southern plume? I'm likely far off base here but what the heck, wild speculation is fun. If anyone finds anything to cut though my wild guesses please let me know and I'll pass it on.

This image was taken with my old, halo prone filters. The bright K5 star really made a mess with my old filters. I left a lot of it in as I found no way to take it out without harming the faint halo around the core galaxies. But compared to the Sloan image of this area I did a much better job with it than they did. I need to reshoot this with more time with the new filters that don't have the halo issue.

The image was taken over 4 nights (one night, while used in the first image was rejected for this one). Many other frames from the other three nights were rejected as well. The result was I am down to my normal 40 minutes of L and 20 for each color. Not what is needed for such a faint feature as the plume, unfortunately. Nor was the night very good. My limiting magnitude is about 21.8 compared to my normal 22.5. That would indicate poor transparency even for the three nights I got usable data. Yet another reason to reshoot it. For now, this reprocess is a great improvement over the original so I'll go with it.

I retook this along with NGC 5371 omitted from this framing. See it for a better image. Unfortunately, it missed the plume.

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

Related Designations for HCG068

HCG069

HGC 69 is a group of 4 galaxies in western Bootes about 400 million light-years distant. Hickson groups, of which there are 100, must meet 4 requirements.

1. There must be 4 galaxies or more with a similar brightness that are brighter than 26.0 surface brightness per square second of arc.

2. The group must be isolated, not a small section of a larger group or cluster.

3. The group has to be so compact their relative sizes are similar to the distance between galaxies themselves.

Oddly, HCG 69 appears to break rule 2. There are a lot of galaxies, larger and smaller in angular size, in the image that are all (including HCG 69) part of a much larger group of galaxies. Note however Hickson doesn't say they all have to be at a similar distance. At the time of his listing, distances weren't all that well known. In fact, the first compact group known, Stephan's Quintet (HGC 92), has one member that's much closer than the others. All Hickson required was they visually appear likely to be at the same distance. In the case of HCG 69, they really are.

They are PGC 49499, 49502, 49505 and 59507. Hickson assumed many of his groups would show gravitational interaction when studied in detail. It's quite obvious from just my image that HCG 69A, PGC 49502, is highly distorted. It and HCG 69C, PGC 49505, are passive nucleus galaxies. A definition of them I found reads: "Passive nuclei (PAS) are typically red, contain exclusively old stars, with no star formation activity: their spectra show both H± and [NII] in absorption. Thus the cores are red and dead though some I've found have jets so not totally dead. No jet is seen in these, however. Also, the entire galaxy need not be dead. HCG 69A has a blue star plume to the southwest indicating it is still forming new stars in that part while much of the rest is rather red. Thanks to this plume it is a huge galaxy which I measure at 194,000 light-years across. Note too that it has a very faint plume going north and a bit easy that goes past PGC 49499. This may indicate the path of yet a 5th galaxy it ate over hundreds of millions of years ago.

Many of the other galaxies associated with the same group as HGC 69 are also rather red and dead with a few exceptions such as ASK 538092.0 to the north of HGC 69 which is quite blue and very actively forming stars throughout as is LEDA 1723672 to the west.

There are 6 IC galaxies in the image 4343, 4344, 4345, 4346, 4348 and 4349. Redshift puts IC 4348 70 or so million light-years further away so it may not be related. The rest, however, are certainly members of the group that contains HCG 69. All 6 were discovered by Stephane Javelle on June 15, 1895.

There's an interesting pair of possibly interacting galaxies to the east-southeast of HCG 69. I found a redshift for only the southern galaxy. So are they interacting or is one well in front of the other so no interaction is possible? Wish I knew.

A quasar to the southeast is listed as having Damped Lyman Alpha emission. For what this means, see: https://en.wikipedia.org/wiki/Damped_Lyman-alpha_system

The stars are a bit flat on the bottom due to tube currents. Normally I let the scope cool to avoid these for an hour before imaging but this night was threatening rain so I didn't open the roof when suddenly the skies cleared with just enough time for one object. That left no time for cooling. I hoped the drizzle had helped cool the scope to ambient but this image showed that didn't happen.

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

Related Designations for HCG069