NGC5698

NGC 5698 is an SBb spiral in Bootes one degree east of Seginus (Gamma) Bootes. It has a rather strange ice cream cone shape with a faint drawn out arm or plume on the eastern side. Usually, such distortion is due to an interaction with another nearby galaxy. NGC 5732 is the nearest candidate with a similar redshift but is perfectly normal looking so probably isn't the culprit. I checked a few others in the area but they were either the wrong distance and/or undisturbed. It could be due to a merger but I found no papers discussing anything to do with its distorted shape or suggesting it has interacted with anything. So how it ended up looking like it does is still a mystery to me. If anyone knows more please let me know. Ignoring the plumes I get a size of 85,000 light-years. Including them, I get 135,000 light-years for a size assuming it is 180 million light-years from us as NED's redshift using the 5-year WMAP data shows. It was discovered by William Herschel on May 16, 1787 but didn't make either H400 observing program.

The other interesting object in my image is LEDA 097532 a pair of obviously interacting galaxies with a plume appearing to connect the two though it could be in front of or behind the other galaxy. Again, I found nothing on their interaction. They are about 480 to 490 million light-years distant. I get a size for the northern galaxy of 43,000 light years and a bit over 100,000 light-years for the southern galaxy thanks to its plumes. The projected distance between their cores is 60,000 light-years. Projected distance assumes they are equally distant from us. Since this is unlikely their true separation distance is likely larger, how much larger is the question?

While transparency was finally excellent for this image allowing me to easily go beyond 22nd magnitude and pick up galaxies NED shows at over 5 billion light-years, seeing would suddenly distort things severely. This resulted in some stars being elongated in various directions and other, often only a short angular distance away, looking normal. I can't recall ever having such distortion before. Very odd.

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

Related Designations for NGC5698

NGC5701

NGC 5701 is a quasi-ringed barred spiral about 80 million light-years distant in Virgo. The arms are very faint. They are quite odd in that the inner half of each arm that forms the ring is red while the center to outer half is blue. I've never seen arms so segregated as to star color (temperature) before. Hot blue stars to the outside of western arm and middle of eastern and in clusters while the red streams are smooth and composed of old, cool, red stars. It was discovered by William Herschel on April 29, 1786. It isn't in either H400 program.

The field around it has several very distant galaxies with redshift data from the WIG catalog (WiggleZ Dark Energy Survey). The one just northeast of NGC 5701 near a bright somewhat orange star at 5.6 billion light-years is listed at magnitude 22.8 if you are wondering how faint this image goes. Slightly brighter at magnitude 22.6 is the most distant galaxy I've picked up at 7.0 (6.962 to be exact beyond reason) billion light-years. To the southeast of NGC 5701 is another that also rounds to 7.0 (6.957) which is a bit brighter. All are listed as emission line galaxies.

I'm reporting this as I researched it. I was really excited about 7 billion light-year galaxies in my image. That's the range of quasars. Turns out I excite easily as no sooner was that sinking in than continuing down the list of WIG galaxies I came upon WIG S15J143912038+05164280 with a z=1.059240. That blew me away. At magnitude 23.4 I didn't expect it to make it through the JPG process but there it was! That, by NED's 5-year WMAP calculations, puts it 8.023 billion light years distant! Yikes. Since this WIG survey is very limited in scope it appears likely that many of the very faint "stars" in my images are unrecognized very distant galaxies. This is the first field covered by WIG I've imaged. There may be more in the more than a year's worth of unprocessed images. I just don't know. This one too is an emission line galaxy meaning it likely has an AGN at its core making it brighter than typical for a galaxy.

It turned out there were many dozen galaxies in the image at or beyond 6 billion light-years that were listed only in the WIG survey. As with the above galaxies, all were very dim and barely able to survive the JPG compression process. So after noting many WIG galaxies within about 5 minutes of NGC 5701 I got more choosy and only picked up those bright enough to certainly survive the JPG compression though you will likely have to enlarge the image to see some of them. Dozens are in the raw FITS file that just won't survive and were therefore not marked.

There are 3 quasars and one asteroid in the image. The asteroid is (7530) Mizusawa at an estimated magnitude of 16.5. The naming citation is rather long.

"(7530) Mizusawa = 1994 GO1
Named in commemoration of the hundredth anniversary of the International Latitude Observatory of Mizusawa, established by the Japanese government according to a resolution adopted by the International Association of Geodesy in 1899 as one of the six stations of the International Latitude Service, at a latitude of +39°08'. In 1988 the Observatory was transferred to the Division of Earth Rotation of the National Astronomical Observatory. The observations have never been interrupted, even during the two World Wars. Mizusawa is located about 500 km north of Tokyo, and its citizens show a strong interest in the observatory's astronomical and geophysical research. Name proposed by the discoverers following a suggestion by K. Hurukawa, who was an astronomer there during 1960-1969. Citation prepared by K. Yokoyama."

14" LX200R @ f/10, L=4x10' RGB=3x10', STL-11000XM, Paramount ME

Related Designations for NGC5701

NGC5714

I've had FGC 1785 on my to-do list for some time but at a low priority as it has only faint detail. Then I realized the field contained an unnamed (as far as I can find) galaxy group at about a half billion light-years that also contained a flat galaxy of even less detail. Though 4 or 5 of the galaxies in the group are from the NGC catalog, they aren't "winners" but red elliptical-like galaxies. Well 4 are, the fifth is very odd and discussed below. Two of the 4 may be interacting. The field lies in northern Bootes.

FGC 1785 is also NGC 5714 which was discovered by William Herschel on May 12, 1787 but isn't in either Herschel 400 observing list from the Astronomical League nor is it to be found in my visual observations logs. At only 130 million light-years it is much closer than the other galaxies in my image. Still, it is quite large with a diameter of about 125,000 light-years. The other 4 NGC galaxies all lie a half billion light-years distant along with many more much smaller galaxies.

NGC 5717 was discovered by John Herschel on April 26, 1830. NED doesn't attempt to classify it but the NGC Project and others say it is a spiral. It is a huge galaxy with a diameter of over 150,000 light-years but very red indicating No significant star formation is going on in it.

NGC 5721 was discovered by R. J. Mitchell an assistant to the Earl of Rosse who likely discovered many galaxies credited to the Earl. He found it on April 16, 1855. It is the smallest of the NGC galaxies in the group with a diameter of only 42,000 light-years. NED doesn't classify it though the NGC Project says it is a compact galaxy. These are small but very dense galaxies, perfect for disturbing larger but less dense neighbors.

NGC 5722 is another discovery of John Herschel and was made the same night of April 26, 1830 as 5717. It appears to have large plumes about it. These may be a result of interaction with NGC 5721 but I find nothing in the literature to support this. Like the others, NED doesn't classify it though the NGC Project says E-S0 which certainly fits both its red color and visual appearance. I might add pec for the plumes. It's bright star ball/disk is about 75,000 light-years across. Adding in the plumes it is much larger. I find it hard to decide where these end. I'd conservatively say it is at least 160,000 light-years in diameter and argue it is at least 10,000 light-years larger than that.

NGC 5723 was discovered by R. J. Mitchell the same night as 5721. Again NED doesn't classify it but the NGC Project says E-S0. I'd lean toward S0. Its major axis is about 80,000 light-years long.

This brings me to NGC 5724 which is quite a puzzle. NED says it is a star but then lists several catalogs showing it a galaxy. So I checked the NGC Project which says it is a compact galaxy. I looked at the PSF in my image which seems to show it likely a star though it is showing a larger FWHM than other stars in the area. The difference is small enough I'd normally ignore it. Next, I checked SIMBAD who says it is a galaxy with a diameter of 8" of arc. That is hardly a star. Then I checked the Sloan image that seems to show a halo about it but a core that is very star-like. The color has a green cast which is very odd for a galaxy but I've seen it with some stars in the survey. Still, that halo would argue for it being a galaxy. With no redshift, it is hard to decide. Dr. Corwin of the NGC Project considers it the faintest identified NGC galaxy. To add to the confusion Seligman says: "Although NGC 5724 is a star, (per NED) many references mistakenly assign it the characteristics of NGC 5424..." This actually makes a bit of sense as there may be both a star and galaxy here. One with the NGC number and the other a LEDA number. This conundrum was discovered by R. J. Mitchel on that fateful April 16th night. For now, I'll say galaxy rather than star and assume the PSF I'm seeing is severely damaged by the very bright starlike core around the faint halo seen in the Sloan image. It wouldn't take much to change my mind, however. Seligman sides with the star hypothesis. He usually goes with the NGC project's Dr. Corwin. Even an amateur level spectroscope should decide this issue. Anyone out there have one?

The annotated image shows many small galaxies also at a half billion light-years scattered rather evenly across the entire field plus the usual assortment of background galaxies. Two of the group members on the left side of my image are interesting. FGC 1790 is another entry from the flat galaxy catalog that's about 110,000 across so a rather large spiral. CG 0497 is an apparent spiral that could have made Arp's list of peculiar galaxies under his category for spirals with one heavy arm. In fact, the only detail I can see in the disk is that heavy arm seen against an otherwise featureless disk of stars. It likely has more detail but the poor seeing this night is hiding it from me. It is about 70,000 light-years across, a respectably sized spiral.

There's an interesting trio of galaxies lies below NGC 5717. One is ASK 402612.0, a wide-open 2 arm, very blue spiral. In a field of mostly red galaxies, it adds a splash of a different color. there are two rather bright red elliptical-like galaxies to its right and fainter ones above and below it. While it is likely the two faint ones are in the background I can't be so sure about the two red ones. Without redshift that will remain an unknown, I suppose. Thanks to its drawn-out arms the blue spiral is some 65,000 light-years tip to tip.

I have other questions that can't be answered as well. Such as is the little galaxy above NGC 5714 a satellite, or a member of the group at a half billion light-years or a totally unrelated background galaxy? Seems the more I look into an image the more questions I have.

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

Related Designations for NGC5714

NGC5719

NGC 5713 and NGC 5719 are a pair of possible interacting galaxies. Most consider them an interacting pair. The pair are located in eastern Virgo at a distance of maybe about 80 million light-years. I found large disagreements here as shown on the annotated image. I'm rather arbitrarily picking the 80 million light-year distance.

NGC 5713 is a highly disturbed SAB(rs)bc pec spiral. It would have fit Arp's one spiral arm category. Including plumes, it is some 70,000 light-years in diameter. It was discovered by William Herschel on April 11, 1787. It isn't in either of the Herschel observing programs.

NGC 5719 is a rather edge on SAB(s)ab pec spiral containing a narrow line AGN at its core indicating its black hole is actively feeding. The slanted heavy dust lane is said by some to indicate the disk is warped. The fainter dust lanes, however, appear rather normal without any slant. One paper that has studied this galaxy finds that about 20% of its stars are orbiting in retrograde compared to the other 80%. The paper says this is likely due to acquiring mostly molecular hydrogen likely torn from both galaxies by their interaction which then has turned into stars. I assume the slanted dust lane has a similar origin? http://adsabs.harvard.edu/abs/2007A%26A...463..883V This galaxy was also discovered by William Herschel on April 11, 1787 the same time he found 5713. It is some 90,000 light-years across including its faint outer regions. It too isn't in either of the Herschel observing programs.

There's a third galaxy that apparently is related to these two on the right edge of my frame which I've labeled as LEDA 135857 (PGC 135857 in some catalogs). Oddly NED also shows it as GAMA 064758. But instead of it being about the same redshift as the NGC galaxies that entry says it is some 3.59 billion light-years distant and calls it a Narrow Emission Line Galaxy which isn't noted for the LEDA entry. If correct it would be some 700,000 light-years across. I think it safe to discard this identification as being a discovery by that all too often cited oriental astronomer Sum Ting Wong. Still, I noted it on the annotated image as well as the likely correct LEDA entry. The same paper mentioned above says it at the end of a large molecular hydrogen cloud created by the interaction of these two galaxies and its stars likely formed from it. If so it is a brand new galaxy some 25,000 to 30,000 light-years across.

Assuming the two NGC galaxies are at the same distance their projected separation is only about 266,000 light-years. Certainly, close enough they are still feeling each other's gravity well. Are they destined to eventually merge? I didn't find anything either way on this.

The annotated image contains 12 quasars plus one quasar candidate (UvES). Arp seemed to think quasars were associated with active or peculiar galaxies. I wonder if he knew of this field? NED listed over 200 objects in the field with redshift information. Many were ELG (Emission Line Galaxies) that were very faint. I point out the brighter ones and a couple of the very faint ones but after that ignored them as it would have filled the image with their catalog entries. It didn't help that this was taken on the same night as my last post so a lot of clouds passing by greatly reduced the depth of this image. My limiting magnitude is over one magnitude less than normal and nearly 2 less than on a really great night. Seeing, however, was reasonable so I didn't put it on the re-do list.

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

Related Designations for NGC5719

NGC5746

NGC 5746 is a nearly edge-on SAB(rs)b? sp spiral in eastern Virgo. It is about 89 million light-years away by redshift. Non-redshift measurements average out to about 86 to 95 million light-years, a rather good agreement. It was first recorded by William Herschel on February 24, 1786. It is in the original H400 program. My log entry from May 17, 1985 with my 10" f/5 on a fairly good night hit by humidity using up to 120x reads: "Beautiful edge-on galaxy. Gradually brighter toward the nucleus which seems off center. A winner. In the same field with NGF 5740." NGC 5740 was also seen by William Herschel that night but it isn't in my image (would have fit) nor is it in either of the H400 projects.

Chandra saw a 120,000 wide halo of rather featureless light around the core region of the galaxy. Even with a 60,000 light-year radius, it doesn't extend across the entire galaxy. Based on the Chandra image I get a distance to the galaxy of 95,000 light-years and a size of a bit over 200,000 light-years. This is one huge galaxy. The Chandra image is at http://chandra.harvard.edu/photo/2006/n5746/ Chandra puts it at about 100,000 light-years. I suppose that could fit the 95,000 light-years I get from their broad estimates.

This was one of my very earliest images and leaves a lot to be desired. 4th magnitude 109 Virginis just out of the field sent in a huge blue halo I didn't have the ability to deal with. Sometime I hope to take it with NGC 5740 but don't hold your breath.

14" LX200R @ f/10, L=6x10' RGB=1x10', STL-11000XM, Paramount ME

Related Designations for NGC5746

NGC5750

NGC 5750 is a ringed spiral galaxy with plumes in northwestern Virgo. Its distance depends on who you believe. NED's redshift data says about 88 million light-years. Others say up to 110,000 using non-redshift measurements. I'm going to round it to 100 million for measuring its size. Not counting the plumes I get a size of about 90,000 light-years which grows to 130,000 including the plumes, especially the one to the northeast. The galaxy is a barred spiral with arms coming off the bar that overlaps forming the ring-like structure. It also has some dust lanes that just aren't where you'd expect them to be. NED classifies it as a Narrow Line AGN while some others say Seyfert 2. In any case, it appears to have a rather actively feeding black hole at its core. The plumes and odd dust would argue this is due to a recent interaction or merger with another galaxy. Was LEDA 1150429 on the far right of my image the culprit? Its redshift is similar indicating it is likely part of the same group as NGC 5750. I found no classification for it. It does appear it could be rather disturbed and is quite blue indicating lots of current star formation is going on.

The annotated image has many Emission Line Galaxies (ELG) and some Narrow Emission Line Galaxies (NELG). The emission lines are narrow not the galaxy. Transparency was better than what passes for normal of late so I was able to pick up galaxies down past 22nd magnitude. This means some rather obscure catalogs had to be used to identify these without resorting to just coordinate names that the SDSS and other surveys use. Others had only coordinate names and are just labeled with a G for galaxy or Q for quasar. Some quasars have a redshift of over 2.5 meaning their light has been stretched 3.5+ times so that even much of their ultraviolet light is now infrared from our vantage point leaving very little in the visible spectrum. Only those with deep UV emissions can be bright enough when stretched into visible light for me to pick up.

This was taken as dawn approached. I tried two additional, beyond my normal 4, luminance frames in a brightening sky. While they were rather noisy they did help a bit to bring out the faint plume of NGC 5750 so I left them in. They were taken after the last of the color data. This resulted in the luminance trail of the two asteroids in the image to be split into two parts with the red and green images taken before the dawn luminance frames.

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

Related Designations for NGC5750

NGC5759

NGC 5759 is a pair of interacting galaxies about 400 million light-years distant in southeastern Bootes. It consists of two galaxies, one stripped of its stars but for the core, the other reduced to a highly distorted spiral. A bridge of stars connects the two. The pair was discovered by Édouard Stephan on June 7, 1880. NED classifies the southern galaxy as S pec. While the NGC Project and Seligman say it is a type I irregular. These are irregular galaxies with some structure but not enough to call a spiral or elliptical. To me, the spiral nature is rather evident. Only Seligman classifies the northern galaxy saying S0/a. A note at NED puzzles me as it reads: "According to [UGC] a pair of galaxies joined by a bridge. The southern one is very compact." To me, it is the northern one I'd call a compact galaxy being mostly a core with a spray of stars. I measure the pair as being about 200,000 light-years across though that assumes both are at the same distance. They likely are at somewhat different distances with it possible there's no actual bridge between them, just two overlapping star streams as seen from our perspective. The lower galaxy has several plumes indicating the interaction may be ongoing with some of the plumes due to other passes of the companion. I wish transparency had been better to see what faint detail I lost to my very hazy skies. I used 70 minutes of luminance, all I could fit in before dawn but still, the image doesn't go very deep.

Below the pair is CGCG 076-042. It is at about the same distance so part of the same galaxy group. It has a faint outer ring around it that I just barely detected. That makes me wonder if it too may have interacted with NGC 5759. I measure it at 120,000 light-years across including the faint outer ring so it too is a large galaxy.

There are many dwarf galaxies also at about 400 million light-years scattered across the image as shown in the annotated version. NED lists a galaxy group, USGC U657 centered a bit east and midway between NGC 5759 and CGCG 076-042 with 11 members but frustratingly gives no angular size. I assume it includes at least my field.

The field contains many galaxy clusters according to NED. The big one being Abell 1970. The label "ABELL" is at its center position. It seems to include most, if not all the other groups. It has a metamorphic classification of GM III which means it is little concentrated with no obvious anchoring galaxy or galaxies.

There were no asteroids in the image but there are several quasars, some rather bright. One is listed as DLyA which stands for Damped Lyman-Alpha. Such quasars are in galaxies with a lot of molecular hydrogen indicating the galaxy is likely in an early stage of formation. They usually reside in galaxies with a redshift of 2 to 4. 2.41 in the case of the one in my image. It's to the northwest of NGC 5759.

This was my last May image. While taken on May 9 the rest of the month was a washout. June was far worse with only a few images taken. My backlog is shrinking rapidly!

14" LX200R @ f/10, L=7x10' RGB=2x10', STL-11000XM, Paramount ME

Related Designations for NGC5759

NGC5774

NGC 5774 and NGC 5775 are a pair of interacting galaxies in Virgo. Papers from 50 years ago considered them non-interacting, an opinion that has changed over the years. NGC 5774 is the blue spiral. It is classed as SAB(rs)d by NED and SBcd by the NGC Project. Redshift puts it 81 million light-years away while Tully-Fisher measurements say 87 million light-years. NGC 5775 is the near edge-on disk galaxy. It is classed as SBc? one place at NED and Sb(f) another. The (f) classification just means it is seen edge-on (not that it is flat as some web pages claim. The NGC Project classes it as SBc without the question mark. Redshift measurements put it about 87 million light-years away. Tully-Fisher measurement agrees. In any case, it and NGC 5774 must be at the same distance to show the interaction seen. I used redshift data for consistency in the annotated image but also show the Tully-Fisher estimate as well. I've not done that before on an annotated image. (Edit: I now do that on all annotated images when available at NED.)

NGC 5774 was discovered by Bindon Stoney on April 26, 1851. William Herschel found NGC 5775 on May 27, 1786. It is in the second H400 program. My data for that got lost in the move to Minnesota. That was my visual notes for it.

A Hubble Space Telescope image of NGC 5775 has been recently released, see link below. Only a week before, by coincidence, I'd imaged this pair. I'm more than a year behind in processing my images but moved this one to the top of the processing list. I don't see in their image all they talk about. The HST image is rotated 90 degrees counterclockwise from my image. Notice along its bottom edge near the right corner some faint stars are resolved. From my image, these appear to be stars in NGC 5774's drawn out arm that extends over or behind NGC 5775. Unfortunately, the HST image doesn't extend far enough to see the arm on the other side of the edge on galaxy. The Hubble image was taken through narrow band filters that distort the color of the galaxy showing extensive HII regions of star formation an odd orange color instead of the more common red-pink color. Hubble has also imaged part of NGC 5774 but only in one band of near IR light. It can be found at the Hubble Legacy site for those of you that are interested. Being only one 640 second frame it is pretty noisy.

The annotated image has many UvES (Ultraviolet Excess Sources) in it. These are likely quasars. Distances to them are determined photographically from the 7 photometric channels of the SDSS survey. This method is approximate but not as exact as spectroscopic measurements. Some are very faint and may be difficult to see. You may need to enlarge the image to find the fainter ones.

HST image of NGC 5775
http://www.spacetelescope.org/static/archives/images/screen/potw1119a.jpg
Text:
http://www.spacetelescope.org/images/potw1119a/

14" LX200R @ f/10, L=9x10' RGB=2x10', STL-11000XM, Paramount ME

Related Designations for NGC5774

NGC5777

NGC 5777 and UGC 09570 are a pair of galaxies in Draco about 100 million light-years away. NED classes NGC 5777 as Sbc and as having a narrow line AGN at its core. The NGC project says simply it is an Sb spiral. In any case, it is seen nearly edge-on making such details hard to see. One paper says that it has a plume. My annotated image points to the "plume" though I see only a slight "bump" to the edge of the galaxy at that point. The paper's image has had the stars removed making it hard to determine where it is looking. My brain can't comprehend mirrored images very well either and theirs is a mirror image of a standard presentation. http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1994ApJ...427..160P&data_type=PDF_HIGH&whole_paper=YES&type=PRINTER&filetype=.pdf

It was discovered by William Herschel on April 17, 1789. It's not in either of the H400 programs.

The companion, UGC 09570 is listed as a dwarf spiral at NED with about the same redshift indicating it is likely a true companion. Its spiral structure is very fuzzy.

The field contains 12 quasars (Q) or quasar candidates (UvES). I wonder what Arp would have made of that since NGC 5777 doesn't look all that disturbed. The disk does appear very slightly warped but that's it. Arp thought quasars clustered about disturbed galaxies and were thus emitted by them rather than being distant black holes in early galaxies. This was just a selection effect, quasars were first found in well-studied fields such as those containing disturbed galaxies. Turns out they are just as common around more ordinary galaxies as this field shows. Few take his ideas seriously any more but last I heard he was still clinging to them.

I found a couple galaxy clusters in the image. WHL J145204.3+590518 with 8 members is to the upper left of NGC 5777. It had a redshift for only the cluster whose position was close (within a couple seconds of arc) of the bright cluster galaxy at its core though there was no redshift for the galaxy, it was listed as being the BCG of the group. The line in the annotated image points to the galaxy. In the lower right is GMBCG J222.41286+58.86499 with 9 members. Here NED lists the same photographic z value and position for the cluster and BCG. As mentioned in previous posts the photographic redshift value is usually less accurate than a spectroscopic redshift but the two, when present, are relatively similar so it is usually reliable to give a general idea of relative distance.

As usual, I stumbled across a couple low surface brightness blue galaxies not listed at NED at all. Some systematic error is omitting them it would appear. Again, these are just two I happened to check, the vast majority weren't looked at so others have likely been overlooked.

14" LX200R @ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount MENGC 5777 and UGC 09570 are a pair of galaxies in Draco about 100 million light-years away. NED classes NGC 5777 as Sbc and as having a narrow line AGN at its core. The NGC project says simply it is an Sb spiral. In any case, it is seen nearly edge-on making such details hard to see. One paper says that it has a plume. My annotated image points to the "plume" though I see only a slight "bump" to the edge of the galaxy at that point. The paper's image has had the stars removed making it hard to determine where it is looking. My brain can't comprehend mirrored images very well either and theirs is a mirror image of a standard presentation. http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1994ApJ...427..160P&data_type=PDF_HIGH&whole_paper=YES&type=PRINTER&filetype=.pdf

The companion, UGC 09570 is listed as a dwarf spiral at NED with about the same redshift indicating it is likely a true companion. Its spiral structure is very fuzzy.

The field contains 12 quasars (Q) or quasar candidates (UvES). I wonder what Arp would have made of that since NGC 5777 doesn't look all that disturbed. The disk does appear very slightly warped but that's it. Arp thought quasars clustered about disturbed galaxies and were thus emitted by them rather than being distant black holes in early galaxies. This was just a selection effect, quasars were first found in well-studied fields such as those containing disturbed galaxies. Turns out they are just as common around more ordinary galaxies as this field shows. Few take his ideas seriously any more but last I heard he was still clinging to them. (Edit: Since this was written he has died. I hope taking his odd idea with him. He was a top astronomer prior to getting this idea stuck in his brain.)

I found a couple galaxy clusters in the image. WHL J145204.3+590518 with 8 members is to the upper left of NGC 5777. It had a redshift for only the cluster whose position was close (within a couple seconds of arc) of the bright cluster galaxy at its core though there was no redshift for the galaxy, it was listed as being the BCG of the group. The line in the annotated image points to the galaxy. In the lower right is GMBCG J222.41286+58.86499 with 9 members. Here NED lists the same photographic z value and position for the cluster and BCG. As mentioned in previous posts the photographic redshift value is usually less accurate than a spectroscopic redshift but the two, when present, are relatively similar so it is usually reliable to give a general idea of relative distance.

As usual, I stumbled across a couple low surface brightness blue galaxies not listed at NED at all. Some systematic error is omitting them it would appear. Again, these are just two I happened to check, the vast majority weren't looked at so others have likely been overlooked. (Edit: Since this was written I've found NED often has this as an Ultraviolet source but not as a galaxy. It returns hundreds of such sources, nearly all blue stars and sorting out the few galaxies is apparently beyond their computer's ability. I certainly don't have the time to try and sort through them all. Once in a rare while, NED does show one as a galaxy and I'll note that. None were in this image.)

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

Related Designations for NGC5777

NGC5792

NGC 5792 is a rather large, in angular size barred spiral galaxy in northern Libra about 100 million light-years from us. I measure it as about 500 arc seconds across its wide arms. That would make it a huge spiral at 240,000 light-years across. To my eye, the far eastern arm is oddly diffuse and appears warped upward as my image is oriented. I found nothing in the notes at NED indicating any warp. In fact, the notes seem oddly at odds with each other. One says: "NGC 5792 is a highly inclined, well-formed barred spiral with an evident almost-complete inner ring from which the grand design two-armed spiral pattern emerges." While another read: "5792 Highly peculiar spiral with overextended spiral arms..." So is it regular or peculiar? I vote for the latter.

One clue to what's going on may be an object NED lists as a separate galaxy embedded in the outer ring that the spiral arms form. NED lists it as a LINER galaxy at almost the same redshift as NGC 5792. Could this outer ring be stars that have been ripped off of this galaxy leaving only a very active blue core behind? Or is it just a star cloud in the galaxy. The LINER label would be one I'd not expect for a star cloud. (Edit: New ideas say LINER is due not to the core but white dwarfs. I can't see a star cluster having enough of them but the idea isn't as odd as it was when I first wrote this.) Yet I found nothing to indicate this might be the remains of a galaxy it is eating. Seems to explain the apparent warp as well as the diffuse nature of the ring like arms as well as it's huge size which is very unusual for a spiral that isn't interacting with another galaxy. Ignoring this outer ring the galaxy is only 200" across or 95,000 light-years. A rather reasonable size for a spiral galaxy. But since nothing is being said about this I have to wonder what is the problem with this interpretation. Though there is a new paper out about fading AGN's that apparently includes this galaxy and may cover this. Unfortunately, it is behind a paywall so I can't see it. The paper indicates the galaxy has been taken by the HST but there's no publicly available HST data at the HST site so it is likely still within the embargo period. http://cdsbib.u-strasbg.fr/cgi-bin/cdsbib?2015AJ....149..155K

The galaxy was discovered by William Herschel on April 11, 1787. I was rather surprised to find that it didn't make either of the 2 Herschel 400 observing programs. Probably explains why I have apparently not logged it visually. The "bright" 9.6 magnitude star that gave me processing fits might make it a difficult visual object.

NED listed a couple hundred very faint galaxies with redshift data in this frame. Unfortunately, transparency was poor this night and my limiting magnitude is only 21.4 or so rather than the 22.7 to 23.5 I can go on a typical night (well typical before this horrid weather set in over 2 years ago now). This made most of them too faint and would have made a mess of my annotated image while avoiding overlapping labels. I did pick up a few in the area of NGC 5792 but they are so hard to see on the lossy JPG I stopped trying to show them which also saved me a lot of time as trying to fit so many labels in and still be able to read them would have been very time consuming and accomplishing little.

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

Related Designations for NGC5792