NGC7535

These three NGC galaxies are located in Pegasus, just below the Great Square. All have a red-shift that puts them about 200 million light-years distant though the two spirals have non-red-shift distances that put them somewhat closer. Their common red-shift would indicate they are part of a local group of galaxies. Several others are located out of the frame. One NGC 7563 has a red-shift similar to the non-red-shift distances and a non-red-shift distance similar to the red-shift distances of the three in my image. Weird.

NGC 7535 and 7536 were discovered by Lewis Swift on September 29, 1886 while NGC 7559 was found by, who else, William Herschel on October 19, 1784 but isn't in either Herschel 400 observing program.

The identity of NGC 7559 has a minor problem. Seems it has a companion seen against its halo to the north that has a similar redshift so they really are related. But how these two are cataloged varies quite a bit. NED considers NGC 7559 to be a double galaxy though I doubt Herschel saw the companion. NED considers the small northern one NGC 7559A and the main one NGC 7559B. Other catalogs call the main galaxy NGC 7559 and the companion NGC 7559B. Others give the main galaxy both the NGC 7559 and 7559A name. Seligman says of this "... providing another example of why such non-standard designations should never be used." He prefers calling the companion PGC 070852 and eliminating the A or B designations entirely.

Just below NGC 7559 half off my frame is ASK 143856.0 another double galaxy but I cut off its companion, unfortunately. Seen at my resolution it would look a bit like a U if I'd have caught it all.

For several years now I've been plagued with lower transparency than I had originally. While not back to normal, the night of this image, July 27, 2017 I had much better transparency than I'd had in some time. Still a magnitude short of what I used to do but it was reaching 23rd magnitude. This allowed me to pick up several galaxies that appear to be part of a group at 5.86 billion light-years that were just at the 23rd magnitude limit. One was even more distant at 6.14 billion light-years. Sure was nice to get improved transparency after all these years. But it didn't last. Soon smoke from fires in first British Columbia then added smoke from the Oregon and Washington fires hit first limiting transparency and then shutting me down totally when even seeing a 1st magnitude star was impossible.

The annotated image shows a faint, tiny, smudge of a galaxy identified as SDSS J231542.74+132957.0. NED shows it with a small blue shift (negative z value). This seems very questionable. NED classifies it as a galaxy but that small and faint it is most likely very distant. While not absolutely impossible I suspect this is likely the work of the infamous Asian astronomer Sum Ting Wong.

I've annotated all galaxies NED listed in the frame with redshift values. I do find it a bit surprising that no verified quasars were in the frame. A few candidates that NED indicated were likely not quasars were listed but not annotated. I've found over the years those with only photographic red-shift, as was the case with these, and for which NED first listed them as stars that have been further researched turned out to be rejected quasars. Therefore I didn't annotate them. I do annotate others that NED had a spectroscopic red-shift for. However, none were in this image so it annotates only galaxies and galaxy clusters. Only two clusters that may be really one were in the image, along the western border.
Normally I'd now include the z value for these distant galaxies but with so many, I didn't take the time and was afraid it would clutter up things even more. As usual, galaxies with only coordinates for a name are just labeled with a G for brevity and a cleaner image.

After a couple nights of good seeing, things reverted to the poor seeing I've had most nights the last few years. At least the better transparency remained.

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

Related Designations for NGC7535

NGC7538

First up is one of the first objects I imaged with the 14" scope back when I didn't have color capability, NGC 7538. Thanks to all the moonlight I was unable to go as deep as I'd have liked so the large faint nebulosity around it is mostly missing. You may barely detect a dark nebula in the upper right corner for instance. That is LDN 1225. Adding H-alpha would help but the skies never cooperated. It is about 9000+ light years away and is in a huge HII complex in Cassiopeia. The Bubble Nebula is part of this complex as well. HII regions are where stars are currently being created in our galaxy. This one is very similar in size to the far nearer and more famous complex that occupies much of Orion and includes the Orion Nebula.

Some call this nebula the "The Ghost Nebula" with the two bright stars in it being the eyes. I can't see it myself no matter how I rotate the image.

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

Related Designations for NGC7538

NGC7541

NGC 7541 is a peculiar spiral galaxy in western Pisces about 110 million light-years distant. It is classified as SB(rs)bc: pec HII though I don't see any HII in my image it likely is in the very odd blue streak which is likely due to very new stars. Notes at NED say it is a disturbed starburst spiral. While it is classified as a barred spiral several say they see no evidence of a bar. The NGC project agrees classifying it as Sc while Seligman says SBc?. So does it or doesn't it have a bar? I see none in any photo (not many) I found of this galaxy. Even the HST image at Seligman's site https://upload.wikimedia.org/wikipedia/commons/c/cc/NGC_7541_HST_10769_814.png shows no sign of a bar that I can see. Maybe it shows only at radio frequencies. Assuming the 110 million light-year distance it is about 100,000 light-years across, similar to our galaxy.

In 1998 SN 1998dh blew just above the end of the blue streak. It resulted in a distance measurement of 108 million light-years when adjusted for the current Hubble Constant value. That agrees very well with the redshift distance. I rounded both to 110 million for the annotated image.

The galaxy was discovered by William Herschel on August 30, 1785 and is in the second Herschel 400 observing program. I've not tried for it visually as yet. To add to the confusion on January 11, 1875 Horace Tuttle reported a galaxy in the area. There's nothing at his coordinates. Dreyer included it in the NGC as NGC 7581. The NGC Project and Seligman both consider it likely it is a duplication of NGC 7541. NED says the identification of NGC 7581 and NGC 7541 is doubtful but if you ask NED about NGC 7581 it returns NGC 7541. My version of The Sky also shows these two as the same object.

A couple minutes south southwest of NGC 7541 is NGC 7537. It has almost the same redshift as NGC 7541 so is likely a companion. I can't say I see any interaction. NED classifies it as SAbc: HII. Again I don't see the HII. Seligman agrees with NED saying it is Sbc? which is equivalent to NED's classification. NGC Project however says simply Sb with no question mark or colon. I measure it at about 70,000 light-years in size. If the two are the same distance from us then they are a bit under 100,000 light-years apart. This distance would cause distortion unless the are just now approaching each other and doing so rapidly with transverse motion so it wouldn't alter the redshift value. I think it more likely they are further apart than redshift indicates. Non redshift measurements put NGC 7537 at about 120 million light-years so close but not close enough to interact. Being the smaller I'd expect it to show interaction before NGC 7541 so it likely isn't the cause of the blue streak in NGC 7541. NGC 7537 was also discovered by William Herschel the same August night he found NGC 7541 but is too faint to make either of the observing programs.

NED has little on the rest of the field. In fact two rather obvious galaxies aren't in NED, Simbad or my The Sky databases so are marked with a question mark. A couple very faint and distant quasars did have redshift. You will likely have to look very closely to find them just to the right of the labels. A couple galaxies in the extended PGC are in The Sky's Database and are labeled in the annotated image but without any distance information. 2MASX J23144719+0438240 is labeled at NED as the upper part of a double blob. Is this one or two galaxies. NED's coordinates center on the brighter blob. To me it appears to be two very blue galaxies but it could be one strange irregular galaxy I suppose. With nothing more it will remain a mystery which it is.

At the very top of the image is a strange comet like galaxy not found in any catalog I checked. It appears to have a double head and a broad tail continuing the comet analogy. I'd love to know more about it but apparently that's not to be. The other unidentified blue galaxy also appears double with the left side larger and brighter than the right. It could be a sloshed galaxy with a bright star cloud or just a strange irregular galaxy. Again there's nothing to go on here.

This field was taken as I hoped to learn something about the odd blue streak in NGC 7541. I found nothing on it other than it is likely a starburst region in the galaxy. Otherwise the field only brought up more questions and answered none.

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

Related Designations for NGC7541

NGC7563

These two galaxies are in Pegasus under the Great Square. Both were discovered by William Herschel on October 19, 1784. Neither are in either of the H400 programs. NGC 7559 is classified as E0 by NED and E/S0 by Seligman. NGC 7563 as SBa by NED and SBa? by Seligman. Both have a similar redshift that puts them about 170 to 190 million light-years from us. They likely are related. Nothing I saw said they were interacting. A couple LEDA galaxies to the east have a similar distance estimate. They are dwarf galaxies, however. Assuming a distance of 180 million light-years I get a size for NGC 7559 of 63,000 light-years for NGC 7559 and 83,000 light-years for elongated NGC 7563. Little UGC 12463 is about 23,000 light-years in size.

This image is another severely hit by smoke that cost me over a magnitude eliminating many small distant galaxies I'd normally pick up. Though most NED had data on were picked up. One galaxy I'd hoped to get was LEDA 1424541 to the southwest of the NGC galaxies. It has an interesting faint outer spiral arm structure I just wasn't able to pull through the smoke. While the smoke cost faint details I believe the colors are reasonable for a change. The smoke particles didn't hit blue and green nearly as hard as earlier in this smoke fiasco.

Low surface brightness LEDA 214925 southeast of NGC 7563 had no redshift but seemed worth at least identifying so I did.

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

Rick

Related Designations for NGC7563

NGC7567

NGC 7567 is a strange, somewhat wedge shaped galaxy in the southwest corner of the Great Square of Pegasus about 180 million light-years distant. It is classified by NED as an Irregular but the NGC Project and Seligman says it is Scd?. That would indicate we are seeing it edge on and it has no dust lane. Not impossible but I prefer NED's Irregular classification due to the shape and lack of a dust lane. I measure it as being about 50,000 light-years in size. Large for an irregular which argues for it being an edge on spiral. The galaxy was discovered by Albert Marth on November 3, 1864.

The other NGC galaxy in the image is NGC 7551 on the western edge of the image. NED has no redshift information or other distance estimates for it. In fact there's little on it at all. Many sources consider it a duplicate entry for NGC 7540 (not in this image). However the NGC Project says this can't be correct as both were discovered by Albert Marth on November 3, 1864 and his position for this galaxy is correct. While it is an obvious near edge on spiral galaxy NED doesn't classify it at all. The NGC Project says S while Seligman says S??.

NGC 7567 and the three PGC galaxies in the cropped image comprise the four galaxy group WBL 702. See the annotated image for what little I found on the three PGC galaxies. Note that PGC 70902 is not a true group member being twice as distant as the other three. Still visually it does seem to belong. PGC 70890 has a small edge on disk galaxy visible either through it or seen in front of it. I vote for it being seen right through the fainter outer portions of the PGC galaxy. It's deeper red color could be due to seeing it through the dust of PGC 70890. I found no designation or anything else on this edge on "companion".

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

Related Designations for NGC7567

NGC7569

NGC 7569 is a rather strange galaxy in southern Pegasus under the Great Square. Red shift puts it some 280 million light-years distant. NED classifies it as S0?. No peculiar label but it sure merits one to my eye. The NGC Project and Seligman both agree with me and add the peculiar label but only Seligman adds the question mark and uses a lower case "o" which is likely a misprint for a zero. It was discovered by Lewis Swift on September 6, 1886. The CGPG says of it: "Compact patches and jets." I can't say I see the patches but what it calls jets, I'd call plumes. That entry was from 1973 which could explain it the "jet" term. A 1971 entry in the CGCG says "Post-eruptive blue disrupted irregular galaxy with compact patches and jets."

I'd say this guy is most likely due to a merger. I tried to look it up at Simbad to see if they had more but their database was messed up and said NGC 7569 was not the name it recognized. Entering coordinates returned its UGC number 12472 and said there were 15 references but when I tried to access them it said they didn't exist. I reported it. Just before sending this they did fix the problem and now there are 17 references but none say anything about the history of the galaxy or the "jets" but for the two mentions above.

Only three other galaxies have redshift value. Two appear related at 340 million light-years. The one with the unusual designation of [OBC97] P04-4 is listed at two positions in The Sky's database under two different PGC numbers neither of which are recognized by either SIMBAD or NED. OBC stands for O'Neil+Bothun+Cornell galaxy catalog of 1997 in case you were wondering. Why neither NED nor Simbad list any other galaxy catalog for it I don't know.

By now you know I like flat galaxies. To better pick up the flat galaxy 2MFGC 17454 I moved NGC 7569 to the east. Note that the ansae of this flat galaxy are quite warped with the northwest end bent up and the southeast end bent slightly down. My resolution isn't sufficient to tell if this is due to wrapping of spiral arms or a real warp. I believe a real warp is likely involved and the nearby spherical galaxy may be the cause however it has no redshift data so I can't tell if they are possibly related or not.

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

Related Designations for NGC7569

NGC7591

HTTP://mantrapskies.com/image-archive/OTHER/NGC7591/NGC7591L4X10RGB2X10.JPG
HTTP://mantrapskies.com/image-archive/OTHER/NGC7591/NGC7591L4X10RGB2X10CROP125.JPG
HTTP://mantrapskies.com/image-archive/OTHER/NGC7591/NGC7591L4X10RGB2X10ID.JPG

Related Designations for NGC7591

NGC7592

My target for this image was NGC 7592, a pair of colliding galaxies in northern Aquarius just below the Circlet of Pisces. When I saw Arp 223 could fit in the frame I adjusted to include it. Though I took it back in 2010, I missed NGC 7592. A mistake I've regretted for all these years but have finally corrected. Unfortunately, while the night was great high in the sky down at -4 degrees I was looking through fog over the lake which greatly cut into my transparency and played havoc with color.

While I knew NGC 7592 was two galaxies in collision, I hadn't realized the huge faint plumes coming from them. I need to revisit this one on a better night with more time to bring them out. They are only hinted at in my image. What I was interested in was that it was a collision between a red and a blue galaxy making for a strong color contrast. The color data for the plumes was in the noise level so not to be trusted. Another reason I need to revisit it on a better night.

Some sources claim it is three galaxies but the third object is just a star cloud in the bright plume of the blue galaxy. Likely the result of massive star formation caused by the collision. One paper thinks the star formation is still going on deep in the cloud but hidden by dust from our view. If that was the case I'd expect the dust to be strong in the 2MASS image and it isn't. The paper predated good IR instruments so this just shows how far we've come in 50 years.

NED does list it as a triple galaxy one place but only because the catalog it is citing does. It knows it is only 2. The annotated image details the individual galaxies as well as a combined system. Red-shift is slightly different for the two but this is likely due to their orbiting each other prior to a final merging.

NGC 7585 I covered in my Arp 223 entry http://www.spacebanter.com/showthread.php?t=155695
https://www.cloudynights.com/topic/271616-arp-223/

I suspect my color data was better then as I had less fog issues in that era. Also, the seeing looks to have been a lot better as well. You can read about that galaxy at the above link.

Just below NGC 7585 is a quasar. It is listed as being 18th magnitude but its position has a 10" error circle that is centered just north and a bit east of the double star I've put the label beside. The error circle does include both but only the brighter meets the magnitude estimate. But it appears red in both this and my prior image. Sloan's image shows it very white with the companion very red. But it uses spectroscopic filters that map red, green and IR to red, blue to green and near Uv to blue. That would indicate it strong in near Uv that I don't pick up. Still, it seems oddly red to me but nothing else fits.

There were quite a few asteroids in the image but many were lost to the fog I was imaging through. I can see four others in the raw FITS data but so far in the noise, I didn't try to pull them out. 5 did make the cut. The likely reason for so many is this one lies right on the ecliptic which passes right through the middle of the image inclined the same as the asteroid trails. Neptune was only about 7 degrees from this field when it was taken. Fortunately, it didn't photo-bomb the image.

There was very little on this field at NED with only one other distant galaxy listed with red-shift data. It is in the lower right. Again the position was poor and pointed between the two galaxies. Only the western edge of the eastern galaxy was in the error circle so that's the one I went with. Also, it meets the magnitude listed for it while the other is a bit too faint by my measurement. Still, I could be wrong.

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

Related Designations for NGC7592

NGC7593

NGC 7593 is an asymmetrical spiral in Pegasus below the Great Square. It also appears sloshed though I don't find a likely cause. The core is well west of the center. One bright arm comes off the south end of the core and curves around the west side of the core while two lesser arms come off the northern side and curve around on the east side. They appear more like chains of star clouds than arms. The core itself is well off center to the west. The core appears elongated north to south as if it were slightly barred but it is listed as Sb by NED, Sbc by the NGC Project and Sbc? by Seligman. Redshift puts it at about 170 million light-years while the median of Tully-Fisher measurements say 180 million light-years. A good agreement. The galaxy was discovered on October 5, 1864 by Albert Marth. Using the redshift distance I measure its longest axis at 49,000 light-years.

Only one other galaxy has redshift data in NED. It is LEDA 2793677. It is the blue smudge of a galaxy to the north and a bit west of NGC 7593. It has a redshift distance of 160 million light-years. It may be a true companion of NGC 7593. While NED had no classification two papers list it as a dwarf galaxy. I get a size of 20,000 light-years so it is indeed a dwarf candidate. To its right is a curving chain of three red galaxies the first of which is under a blue star. I couldn't find anything useful on them except they did make the 2 micron survey of IR galaxies.

There is an obvious spiral to its southwest. NED doesn't even list it as a galaxy, just as a UV source found by the Galex satellite. Most are just stars rich in UV but some, like this one, are galaxies. The only survey to cover this area is the 2MASS that picks up galaxies rich in IR at 2 microns. Apparently, this galaxy has enough UV to make the UV survey but not IR to make the IR survey. With nothing else to annotate I didn't prepare an annotated image.

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

Related Designations for NGC7593

NGC7594

The WBL 706 galaxy group has three members. They are NGC7594, IC 5305 and the double galaxy of LEDA 1376799 and IC 5306 though IC 5306 is only a line of sight galaxy. The three true members are all about a half billion light-years distant. NGC 7594 is an Sb galaxy with a redshift distance of 470 million light-years but on-redshift measurements have a median value of 420 million light-years and a mean value of 530 million light-years. IC 5305 shows a redshift of 460 million light-years while LEDA 1376799 has the largest redshift of 530 million light-years. The outcast IC 5306 is only 330 million light-years distant by redshift. Though other galaxies are apparently true members of the group such as IC 5307 at 54 million light-years and PGC 070958 at 53 million light-years they aren't part of the WBL group for some reason (too far away from the other three by angular measurement? The group is located in Pegasus below the Great Square.

Since these are quite distant galaxies but have a reasonable angular size they must be huge. NGC 7594 is about 200,000 light-years across making it one of the largest known spiral galaxies. LEDA 1376799 is 131,000 light-years in diameter while IC 5305 is only 80,000 light-years in size. I should probably mention that measuring the size of such distant galaxies has an additional complication not found with nearer galaxies. During the half billion years the light has been heading our way the universe has expanded. So while we see these galaxies at one distance they were closer when the light left. We see their size as it would be if they were at the distance they were when the light left but measure their distance in light travel time as greater. That means we get a size that is too large. In fact, we call its distance when the light left its angular size distance. At some point this difference is material. I usually round distances to only two significant digits so it hardly matters in most cases. But since I get asked about it decided its time to address this issue. In the case of NGC 7594, its angular size distance is about 2 megaparsecs closer. If I use the redshift look back distance to calculate its size and use all 3 significant digits at NED (0.473) and its measured size on my FIT of 90 arc seconds that makes it 206,000 light-years across. Using its Angular Size Distance of 143 megaparsecs (0.466) its size is 203,000 light-years. Being conservative I used 200,000 above as I round to 2 significant digits since the calculation was done using 3. I always use one less significant digit in these posts. Since the two values are on opposite sides of the rounding point if I'd have used the look back distance for the calculation it would have been 210,000 which is too big by 5%. Since there are so many error bars involved here even using 200,000 might be a bit overstating the actual accuracy of the computation. I could throw out that during the half billion years the light was on the way the galaxy actually moved further away than the light travel time indicates and it is now really 148 megaparsecs distant (482 million light-years). I'm assuming values NED uses for their 5 year WMAP calculations. Change these values and the distances change accordingly. New values come out every few months. I've stuck with these over the years to make all my posts comparable. If I kept changing each time a new value came out I'd have to change all prior posts to match and with over 1000 of them now that is impossible. Again the various error bars involved and my rounding likely makes this difference rather immaterial.

NGC 7594 was discovered twice. First by Andrew Commen in August 1880 and again by Guillaume Bigourdan on August 22, 1889. The latter was entered into the IC catalog as IC 1478. This is why I listed both on the annotated image. Andrew Commen was an English astronomer who used a 36" f/5.9 reflector. He later sold this in 1885 to a rich carpet baron on England by the name of Edward Crossley who set up his own observatory using the scope. But English weather got the best of him and gave up the astronomy side of his life. He donated scope and dome to Lick Observatory where it was known as the Crossley reflector for its donor. It was only recently retired from research service. http://www.ucolick.org/public/telescopes/crossley.html

IC 5305, 5306 and 5307 were discovered in 1897 by Hermann Kobold using an 18" refractor at Strasbourg Observatory. He found 38 IC objects but 4 turned out to be stars. The majority of his discoveries were galaxies in the Coma Cluster.

This field is poorly mapped. Only a few galaxies had redshift values. Most have no redshift. Those listed by NED are mostly from the 2MASS catalog and often don't even have a magnitude. Most of the background galaxies, however, don't emit enough 2 micron radiation to make that survey. Those that are strong in Ultraviolet made the Galex satellites catalog of Ultraviolet Sources (UvS) but so far NED lists those solely as UvS. Most are stars, some galaxies but NED makes no distinction. Also, the resolution and pointing accuracy of the satellite was low by today's standards so the positions are somewhat vague. Since the annotated image was rather sparse due to lack of redshift data I included the brighter 2MASS objects by designation (just their coordinates in the sky). I didn't even do that with the UvS galaxies I noted. Just listing them as UvS. Many more UvS and 2MASS galaxies are in the image. I didn't see much use in pointing the few remaining 2MASS galaxies out and separating galaxies from stars in the Galex catalog is a super time-consuming task with hundreds to go through. Probably why NED hasn't done so as yet.

There are three asteroids in the image. See the annotated image for details.

I should note I have no idea why I took this group. It isn't to be found on my to-do list in any category. That means I had to interrupt the auto selection process and go to it manually. Something I rarely do unless a supernova, comet, near earth asteroid or other in the news object, comes up. That doesn't seem to be the case here. I did enter it in the log under the NGC 7594 designation, not the galaxy group designation which is also odd. I made no note however as to why it was taken. While the edge on galaxy made the 2 micron flat galaxy catalog it isn't thin enough for the Flat Galaxy Catalog so that isn't the reason, besides I'd have logged it under that galaxy, not NGC 7594. Apparently, I figured I'd remember why when I processed it but I don't. The why will have to remain a mystery.

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

Related Designations for NGC7594