NGC7606

NGC 7606 is an example of a spiral galaxy with a hole in its spiral structure. Arp apparently didn't find these odd enough to include in his atlas. Besides the hole, the arm structure is rather weird. An odd arm runs to the southeast has an odd wave to it suddenly diverting from the normal spiral pattern. Most arms have some odd structure. What caused this is unknown to me. NGC 7606 is located in Aquarius about 100 light-years away. Redshift at NED puts it about 86 million light-years away though other measurements at NED indicate 92 to 113. Adam block at NOAO says 98 million light-years. I'll settle on a nice round 100. It was discovered by William Herschel on September 28, 1785. It didn't make either H400 program.

Several notes at NED go into its physical description but no one mentions the odd "hole" in the spiral structure at the northern end. It does appear star formation is declining in this galaxy. Adam Block goes so far as to say: "Astronomers note that this galaxy is settling down in the rate of star formation. Soon (in galactic time) this galaxy may form a barred nucleus in its center with a ring of material surrounding it." I'll put it on the list to reimage in a few hundred million years and see if his prediction comes true -- or not.

NED classes it as SA(s)b with some HII emission. Odd to find that HII mentioned if star formation is ebbing as rapidly as the notes seem to indicate. NGC project classes it more simply as Sb+ I.

I prepared an annotated image though only a few galaxies had redshift data. It seemed only the faintest objects had redshift information. Many were quasar candidates. NED identified them as Ultraviolet Excess Sources (UvES) so that's the label I put on them. Oddly the close ones were very faint while the two over 10 billion light-years distant were the brightest. Just goes to show you can't judge distance by brightness. QSOs aren't standard candles.

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

Related Designations for NGC7606

NGC7619

Two giant elliptical galaxies are at the heart of the Pegasus I galaxy cluster which is about 160 million light-years distant. NGC 7619 is the brightest member and likely the most massive but otherwise is a rather normal elliptical galaxy. The other major member is NGC 7626. It is a shell galaxy indicating it is the result of a rather recent merger. The shell is easiest to see on the eastern (left) side. Notes at NED indicate it has a dust lane at the core though I was unable to find it in my image. These features, as well as others, cause it to be classified as being peculiar. It also has a LINER core, another indication of the merger that created the shell. Notes also indicate that NGC 7619 likely harbors a lot of dust areas as well. NGC 7619 is about 180,000 light years across its major axis. NGC 7626 is slightly larger, about 195,000 light-years. This larger size is likely due to the merger and only temporary. Both are likely larger than my estimates as determining where the edges are is difficult though NED gives sizes somewhat smaller than I'm seeing. Both were discovered by William Herschel on September 25, 1785. Both are in the second H400 program.

Another rather distorted galaxy in the group is MCG +01-59-058. It is listed as SB? by NED. It seems a rather normal small spiral except for that huge faint arm that pushes the main disk way to the east side of the galaxy making it look "Sloshed". UGC 12510 is listed as E in NED but I see faint arms making it look like a disk galaxy rather than an elliptical. Note the apparent bright linear feature in the lower arm is due to unresolved stars in our galaxy plus a distant background galaxy. They do add to the spiral appearance. It's best to look to the northern side where such background and foreground objects are lacking.

There are 6 other NGC galaxies in the image. I've listed their discoverer and the date below.
NGC 7611, May 26, 1863, Heinrich d'Arrest
NGC 7615, August 16, 1830, John Herschel
NGC 7617, September 23, 1864, Heinrich d'Arrest
NGC 7621, November 25, 1864, Albert Marth
NGC 7623, September 26, 1785, William Herschel This one is in the second H400 program.
NGC 7631, August 30, 1851, Bindon Stoney

In making the annotated image I found nearly all with distance data were members of the cluster so carry a distance of about 160 million light-years. For those, I omitted writing 0.16 over and over. Only those obviously not a member have their distance shown. Some rather bright galaxies had no redshift data. Those are listed with na for not available. They are likely cluster members but I can't say for sure.

Two asteroids are shown in the annotated image as well.

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

Related Designations for NGC7619

NGC7635

The Bubble Nebula, NGC 7635 is a famous nebula in Cassiopeia. I find a range of distances for it from 7 to 11 thousand light-years. That results in a size ranging from 3 to 5 light-years. The bubble is being blown by the bright blue star to the upper left, far off center. The usual explanation is that the density of the material being blown by the stellar winds of the star are densest in this direction preventing its expansion being as rapid this direction. I'm bothered by it still being rather round. I'd expect it to be quite flattened this way. The star creating this bubble, SAO 20575 is an O star. These are extremely hot, supermassive but short-lived stars. Most of their light is emitted in the ultraviolet part of the spectrum so to our eyes it appears dimmer than it really is since we can't see ultraviolet light. The star is thought to be about 4 million years old and will only live some 10 million years, one thousandth as long as our much smaller star. It will end its life as a black hole. Until recently it was thought this meant it had to go supernova. Now we think some stars of this size go directly to the black hole stage without ever going supernova. Stick around another 6 million years and see what happens.

The bubble was found by William Herschel on November 3, 1787. It is in the second H400 program.

A three-dimensional simulation of the smaller bubble can be seen at https://www.nasa.gov/feature/goddard/2016/hubble-sees-a-star-inflating-a-giant-bubble

14" LX200R @ f/10, L=6x10' RGB=3x10', STL-1100XM, Paramount ME

Related Designations for NGC7635

NGC7638

NGC 7638/1483 appears to be a very disrupted spiral galaxy in Pegasus about 350 million light-years distant. It was discovered by Andrew Ainslie Common on August 8, 1880. Unfortunately Common gave no coordinates for this one or NGC 7639 he found the same night. Just a rough estimate of distance and direction from NGC 7630 (out of my frame) Dreyer entered these into the NGC with approximate coordinates. Later Stephane Javelle, on December 2, 1893 found both of these with good coordinates so we know these are what Javelle saw. Not realizing they may be what Common recorded they got a separate listing the IC catalog. Since nothing else is in the area Common would have seen in his scope it is assumed he saw these as well. Since his observations came first to Dreyer's attention they went into the NGC and Javelle's more accurate observations went to the IC without anyone catching on at the time they were likely the same two galaxies. But this is still debated, hence the question marks after their designation in the annotated image.

NED lists two galaxies at NGC 7638's position with their coordinates only a few pixels different in my image. The position for 7638 is the optical center where there's no obvious object while the NED01 position is centered on the brightest point in the galaxy. I see no second galaxy even in the Sloan image. The second is listed as NGC 7638 NED01/IC 1483 NED01 and has the same .6 minute diameter. But it has no magnitude estimate to compare to that of NGC 7638. NGC 7638 carries the PGC 071242 label while the NED01 galaxy is AGC 330294. Neither the PGC nor AGC have a second galaxy listed. While it is tempting to say this is two overlapping interacting galaxies I can't see anything in any image I found of it to support this.

NGC 7639/IC 1485 is a pretty normal E/S0 galaxy at the same distance as NGC 7638. Between them in my image is KUG 2320+110C a spiral at nearly the same redshift so likely a member of their group. Nearby is the double galaxy KUG 2320-110B. Its angular size is smaller than the others. With no redshift, I can't tell if that means it is more distant or just two overlapping and possibly interacting small members of the same group. With nothing else having redshift data the annotated image is pretty sparse of data.

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

Related Designations for NGC7638

NGC7640

NGC 7640 is a nearby near edge on galaxy (nearby for galaxies I normally image) in Andromeda. I was unable to find an agreed upon distance for this one. Some place it as close as 19 million light-years while the furthest estimates put it a bit over 32 million light-years. Due to my limited resolution of stars in the galaxy, I'd have to prefer the further estimates. The reason it made my to-do list was the odd extended southern arms with a hole in them. I saw the hole in the blue POSS II plate. Though it was more pronounced in my image than I expected, looking almost like a dust donut in my flat that wasn't in the image. It is a real feature, cause unknown. It may just be an illusion due to our viewing angle of the very extended arms. NED classes it as SB(s)c while the NGC project says S(B)b. Both indicate it as a rich source of HII. I should have read that last year when I took the image. I'll have to put it back on the list, at least for HII purposes later this summer. It was discovered by William Herschel on October 6, 1784. It is in the second H400 program.

There's virtually nothing to be found on the field. NED has no redshift data for anything but NGC 7640 and that is worthless as a distance measure putting it only 3 million light years away which is very unlikely to be the case.

Only one of the many background galaxies in the cropped image is even in NED. It is a very blue blob seen apparently within NGC 7640. To find it follow the right edge of the galaxy down from its center. You will come to a very bright star with two medium bright blue-white stars below it. The bottom one of the pair being fainter than the upper. From the bottom one go left just past the mid-line of the galaxy to a very blue blob. This is the 16th magnitude galaxy NPM1G +40.0521 according to NED. While no "pretty picture" of this galaxy has been released by the Hubble Space Telescope some core images are available at the Hubble legacy site. Showing only the core region they don't go down to this object. It may very well be a distant background galaxy but another blue blob in my image somewhat further up and a bit further toward its left edge is in the Hubble image and is a star cloud in the galaxy. They look very similar (star cloud is smaller) in my image. The object is only in the NPM1G catalog. All the other galaxies in the full image that are in NED come from the 2MASX catalog so are IR strong galaxies.

14" LX200R @ f/10, L=7x10' RGB=2x10'x3, STL-11000XM, Paramount ME

Related Designations for NGC7640

NGC7649

Abell 2593-N is the northern part of the much larger Abell 2593 cluster. Oddly the center of the full cluster is NGC 7649 which is also close to the center of Abell 2593-N. Abell 2593-S is rather sparse and south of this frame. The cluster is a bit over a half billion light-years distant in Pegasus just south of the Great Square. While the cluster is larger than my field I show over 125 members in this frame. Oddly this is the number listed in NED for the entire cluster. Apparently, they are being conservative There also appears to be a group at about 900 million light-years as well as another just over 2 billion light-years distant. Some of the latter are larger and brighter than many members of Abell 2593 even though 4 times more distant. One asteroid stuck its nose into the frame. It may be rather hard to find among all the galaxies.

NGC 7649 which anchors the cluster is the only NGC object in the cluster. On November 25, 1886 Lewis Swift discovered the galaxy and listed it as #96 on his list. On October 15, 1887 he recorded a galaxy in nearly this position as #99 on his list. Dreyer recorded the first as NGC 7649 and the second as IC 1487 not realizing they were one and the same galaxy. You can read more on this at the entry for NGC 7649 at the NGC project. NED and the NGC Project list it as E even though it is obviously rather elongated. Seligman says E2? Even that doesn't indicate how elongated it is. I'd say E6 or even higher. Since it fades into the background determining an edge isn't easy. I can definitely say it is at least 250,000 light-years in size, most likely considerably larger. It certainly is a huge galaxy.

A few quasars (Q) are far in the background. I included a few candidate quasars (CQ) as well. These often turn out to be stars whose spectrum has absorption features that mimic great redshift when that's determined photometrically. Often these are exposed when a good spectroscopic redshift is determined. So treat these as highly suspect. Photographically determined redshifts are noted with a "p".

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

Related Designations for NGC7649

NGC7651

ABELL 2593-S is the southern part of the ABELL 2593 cluster. The northern part is out of my image, to the north, obviously. It is located in Pegasus just below the Great Square and is about 550 million light-years distant. For the northern part see my image of ABELL 2593-N taken nearly 2 years ago without any smoke to deal with.

The cD galaxy anchoring the southern cluster is NGC 7651, a double galaxy. While NED identifies the two parts with a NED 01 and NED 02 label most sources list the main galaxy under the NGC 7651 name and the companion under its PGC 3085862 or other separate designation. I've gone with this method for the annotated image. Oddly while NED gives virtually the same red-shift for both they give a different one of 570 million light-years for the double galaxy. How this comes about I don't know. Seems a problem to me that the whole is more distant than its parts.

The discovery of NGC 7651 is attributed to Lewis Swift on September 1, 1886. I doubt they mean the double galaxy now known as NGC 7651 but just the big main one. I doubt Swift's telescope could see the companion as a separate galaxy and doubt it would have been seen alone. Also, Swift's position was about a half minute of arc east of its true position but all sources agree it was the only galaxy he could have seen so consider the identification as certain.

NED had non-redshift distances for some galaxies in the cluster. Most consisted of only one estimate and it was always 170 parsecs. Were they using the same measurement for all? I've never seen such consistency before and find it highly suspect but included them anyway. Some of the tiny, apparently distant galaxies turned out to be dwarf cluster members while others were really distant galaxies.

The image contains many very distant ones but unfortunately, this one was taken the same night as Berkeley 103 through very dense smoke from fires in the northwest and British Columbia. This meant most were lost in the smoke but for the reddest ones. Dust passes red light better than shorter wavelengths so very red distant galaxies were seen when much bright but bluer ones were lost to the smoke. The smoke also created havoc with color balance. EXcalibrator, my go-to program for color balance left everything still a magnitude or more too red and left red halos around even blue stars. Edges of stars and galaxies were all deep red due to fainter blues and even greens vanishing in the smoke. I should never have taken color data until the smoke cleared but didn't realize the problem was so severe until too late to retake them for this year. Maybe I should have just stayed with a mono image.

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

Related Designations for NGC7651

NGC7656

NGC 7656 is below my normal cut off as seeing down this low is rarely sufficient. The night I took this was no exception. It is so strange I had to try anyway. I tried several nights, this was the best of the bunch. It was recommended to me by Sakib Rasool who had this comment in his email: "(E)ven Sherlock Holmes would have difficulty in deciphering the history of this bizarre deformed galaxy!" It is located in the southeastern corner of Aquarius about 330 million light-years away. This case was first noted by Francis Leavenworth on October 9, 1885.

Several "Sherlocks" have tried over the years. NED calls it SO pec while the NGC project leaves off the peculiar tag. NGC catalog notes say: "3 filaments - 2 in loop." Those are pure descriptions with no attempt at explaining what is going on here.

So bring on the Sherlocks. Latest paper I found says this:
This is probably, at least, a disrupted triple rather than an E + disrupted S. Merger in progress? The main body is E-like and shows boxy isophotes. The intricate series of arms is probably a result of interaction or dismemberment. We see compression of the isophotes in the main body on the side opposite the next largest component.
http://adsabs.harvard.edu/cgi-bin/bib_query?1992A%26A...259...43R

7 years earlier I find:
Interacting triple system with loop and plumes. 1st in small cluster.
http://adsabs.harvard.edu/cgi-bin/bib_query?1985ApJS...57..643D

17 years before that in the VV catalog we see this pure description:
Unusual interaction. From N part extend three wide arcs, the two eastern ones almost forming a knot, in the northeast part of which three companions are found: 17 mag [N] at 0.4 arcmin, 19 mag at 0.7 arcmin and 18 mag [N] or star at 0.8 arcmin. The west arm is not very clear and does not connect to anything.

And that's about it. I'm not even sure what are the three interacting galaxies. NED lists only two objects in the immediate area with a third a bit to the northwest that shows no hint of distortion but is at 320 million light-years by redshift. So a member of the same group at least. But doesn't seem to be the third member. The most likely candidate is the object to the northeast of NGC 7656 itself. My seeing was about 4 arc seconds FWHM but this object comes in at 8 which would not fit a single star. It is marked with a question mark in the annotated image. Thus it is likely a galaxy though not listed in NED nor is this field covered by the Sloan survey which cuts off at the very northern edge of the plumes. Close but no cigar and very frustrating. The object with the plume is listed but with no redshift, so it gets a name but a question mark for distance in the annotated image. This unknown object seems to be in the brightest part of the looping plume. It's possible the plume is due to either stars ripped from it or that it has ripped from NGC 7656 or both.

Only a very few other galaxies in the field have redshift data. So few I found it easy to include their names as well as distance. All appear to be members of the same group of galaxies.

There are three asteroids in the image that are identified in the annotated image. The minor planet center listed a fourth that was plenty bright to see but I couldn't see it. This had me puzzled until I noticed the note "Leave for survey recovery." This means the orbit they had was insufficient and it is now lost. No wonder I couldn't find it, it wasn't there.
(200467) 2000 WG165 at magnitude 18.9
(78615) 2002 SH59 also at magnitude 18.9
(79496) 1998 FK91 at magnitude 19.2

Due to poor signal, this low in the sky the luminance channel is a combine of all LRGB frames rather than just the L frame. This cost some faint detail but greatly helped the signal to noise ratio. The asteroid trails were greatly reduced by this combine but are still visible at least. Also due to extinction this low I used 30 minutes for each color rather than my normal 20'. The extinction still won I'm afraid. It's rather bad in September when this image was taken.

14" LX200R @ f/10, Pseudo L=13x10' RGB=3x10', STL-11000XM, Paramount ME

Related Designations for NGC7656

NGC7662todo

NGC 7662 is commonly known as the Blue Snowball. It is located in Andromeda about maybe 5 or 6 thousand light-years distant. Other sources make it closer at 2,000 light-years. Distances to planetary nebulae are hard to pin down. The nebula was discovered by William Herschel on October 6, 1784. My log entry from July 10, 1985 on a night with steady air but not so great transparency using up to 180x in my 10" f/5 reads "Brilliant, round, blue ball, planetary nebula. Seemed slightly darker toward the center but this may be an illusion. No central star was seen. Probably should have used higher power as the air was unusually steady this night." Images show the center is darker so it wasn't an illusion. Also, the central star is variable ranging from 14 to 16th magnitude. I might have glimpsed it through the nebula at 14th magnitude but not at its faintest of 16th magnitude.

The nebula has three shells, I picked up only the two brightest. That's because in my beginner ignorance I used very short exposures of 2 minutes. The read noise of my camera would hide the faint outer shell at that exposure time. Besides, I didn't know of the third shell at the time. I do need to retake this one with more exposure time than the 2 minutes per frame I used. Also, I was working at 0.5 seconds per pixel rather than the 1" per pixel I used back then. I didn't understand how that made the read noise even worse. I need to redo this one using more reasonable exposures to pick up the third very faint out halo. Fortunately, there's not much detail in the outer halo so I can use a typical night to get that part and combine it with the higher resolution of this image a 0.5" per pixel.

14" LX200R @ f/10, L=5x2'x1 RGB=2x2'x2, STL-11000XM, Paramount ME

Related Designations for NGC7662todo

NGC7667

UGC 12578 (lower right) and UGC 12589 (upper left) are a pair of galaxies in western Pisces. Both appear highly disturbed but are unrelated. UGC 12589 is 4 times further away at 440 million light-years than UGC 12578 which is only 110 million light-years away.

UGC 12578 is classed as SB(s)m pec by NED and SBSm by the NGC project. It contains many HII regions that show blue in my image due to all the super hot blue stars they contain. 5 of them are noted in the annotated image. They seem to fall into two different redshift classes. This makes me wonder if this highly disturbed galaxy is the result of a merger. The two different radial velocities being due to the two star populations. One HII region seems completely separated from the rest.

Adding to the confusion is that UGC 12578 is sometimes identified as NGC 7667. The NGC project says this is possibly true but considers it questionable. NED says: "Identification as NGC 7667 is very unlikely." The Sky found it using the NGC number, however. There's a nice discussion on the NGC project under the NGC 7667 designation for those interested in this. Edit: For now the site is down, it may or may not be rebuilt. Many consider NGC 7667 as lost. What I've identified as NGC 7667 may have been first seen by Gaspare Ferrari when looking for Biela's comet on December 21, 1866. His position is vague. The identification of NGC 7667 is also vague.

UGC 12589 is a pair of interacting galaxies with UGC 12589 Notes1 to the northeast. Both are highly distorted. NED shows the southwest galaxy as containing several objects it classes as galaxies rather than parts of a galaxy. I suspect they really aren't separate. Two of them I've identified in the annotated image, one had no redshift. The other two had very imprecise coordinates centered on empty space with huge error bars. I gave up on trying to locate them. The southwest galaxy is classed by NED as SB(s)m pec. The companion UGC 12589 Notes 1 has a nice long tidal tail to the east. It is classed by NED as (R')SA?(r)a? NLAGN. The last stands for Narrow Line Active Galactic Nuclei. Likely a left over from the interaction with its companion. NED shows other companions. UGC 12589 Notes 3 (not shown on the annotated image) is just the northeast end of the southwest galaxy. For it, NED has this cryptic note: "Part of UGC 12589, or one of four interacting spirals." They can't decide apparently. UGC 12589 Notes 2 turns up a not found error at NED. Not sure why. The other, UGC 12589 NED04, has very imprecise coordinates centered on empty space with large error bars. I gave up on trying to locate it. The error bar for NED03 was so great I could only conclude it was possibly the northeast end. Don't quote me on that, however. Neither made the annotated image because of their fuzzy location data.

I processed the background far deeper than I normally do which makes it rather noisy. Nearly all the thousands of faint, apparently noise islands, are really extremely distant galaxies. I could have filled the annotated field with their distance labels as a surprising number had redshift data. Seeing that as not really accomplishing much I only identified a rather random selection chosen to spread them across the image rather than fill up a small area with labels. Though in two cases I found close pairs with virtually the same redshift so did label those. After finding some 4000 down past magnitude 25 identified in NED (My limit is about mag 23.3 depending somewhat on which color filter I'm using), I was surprised to find one in the upper left not listed at all! I checked the Sloan data and it is clearly shown on their image. Just that NED never picked it up.

The image is also rare in that several quasars are far closer than some galaxies. One galaxy is over 8 billion light-years away, light travel time distance using NED's 5 year WMAP calculations. Another is listed at 9.7 million light-years! It is listed as an emission line galaxy rather than a quasar. It is surprisingly bright (magnitude 21.0 in green light) for an ELG. Could it be a still unidentified quasar? I can't imagine a galaxy that bright at that distance. It's labeled east of UGC 12589 along with its designation so you can look it up at NED. That's got to be one bright galaxy for me to see it that far away. A much fainter one at 10 billion light-years is nearby. The image is chock full of galaxies over 5 billion light-years distant by the same measurement. Most of the faint fuzzies in the background likely fall into this class as well. I know many of them do as I looked them up, just didn't label them.

The image contains two asteroids; (293027) 2006 WM62 at magnitude 21.1 is in the lower left corner. (167817) 2005 CY5 at magnitude 20.5 is one-third of the way between UGC 12589 and the other asteroid. Normally I don't show asteroids this faint, just noting they were in the raw FITS but didn't make it through processing a color image. This time, due to the tremendous number of faint galaxies in the image I did take the time to bring out the faint background objects. It takes a night of superior transparency and no moon to accomplish this, don't expect this to be a common occurrence. Especially how the weather has stunk things up the last year.

This is my last August 2011 image. I'm now officially less than a year behind in my processing!

14" LX200R @ f/10, L4x10' RGB=2x10', STL-11000XM, Paramount ME

Related Designations for NGC7667