NGC6664

NGC 6664 is an open cluster in Scutum discovered by William Herschel on June 16, 1784. It is in the original Herschel 400 observing program. That's how such a nothing object ended up on my to-do list. Some sources list it as 12 minutes of arc across while others say 16. In either case, it is fully in my image's field. Just which stars are members of the cluster isn't all that obvious. My description of it from May 20, 1985 using a 10" f/5 under good viewing conditions at 65x reads: "Large sparse, scattered star grouping. Makes me wonder if it is a true cluster or just a bright region of the Milky Way. Seems to have no definite edge as it just fades into the Milky Way." Apparently, I was having trouble making it out visually as well. Though the cluster is classified as III2m which means it is rather weakly concentrated (IV is most weakly concentrated), has an average mix of star brightness and moderately rich in stars. That seems to overstate it at least as I saw it visually and in this image.

WEBDA says it is 3800 light-years distant and about 14.5 million years of age. That would make its stars mostly very blue but that isn't seen in my image. Then I saw it was reddened by 0.7 magnitude. That could account for the stars being less blue than expected. It obviously isn't one of the better Herschel 400 open clusters. But one more off the to-do list of H400 objects far enough north for me to catch.

Conditions were not good for this one. I had to do some heavy deconvolution to get sort of round stars. Color data was so poor I only used the one best color image for each color. Even then, the stars were not all that similar on each color frame causing severe color effects where stars had a spike in one color or another due to the lousy seeing. Also, Alpha Scuti sent in a nasty flare that ran across nearly half the frame. I tried some new techniques to remove it that worked fairly well. Only because just stars were involved. I doubt it would have worked if faint galaxies had been in the background. They'd have been removed as were a few very faint stars. Unless you know the 19th magnitude and fainter stars in the image I doubt you will miss the few that vanished along with the reflection spike. Rather time-consuming and not something I'll do often. I only removed it in the luminance frame. In the RGB data, I just used the same isolation technique to select it but not the couple hundred stars it covered then reduced it to neutral gray. That prevented it from coloring the luminance image with no need to remove it.

Transparency was very poor. I ended up using 5 luminance frames to go less deep than I usually do with 4. I needed this to use the heavy deconvolution used to round out the seeing ruined stars.

14" LX200R @ f/10, L=5x10' RGB=1x10', STL-11000XM, Paramount ME

Related Designations for NGC6664

NGC6667

This is one messed up galaxy, in more ways that it may first appear. First off it is obviously a highly disturbed galaxy with huge plumes. These would indicate it is a result of a recent merger. Also, it is quite red, even the plumes aren't very blue indicating the merger didn't result in much new star formation in these plumes. Usually, tons of new stars form in these plumes making them rather blue in color due to the short-lived massive blue stars that form there. But this galaxy has an overall reddish hue, while some areas look blue if you check the color in an image processing program you'll find even those areas are somewhat red. It's just that thanks to the contrast to the very red regions these look somewhat blue when they really aren't. So we are seeing an old galaxy here. If new stars are forming they are hidden behind dust shields, likely near the galaxy's core. It is classified at NED as SABab? pec. The NGC project says Sbab/P. This is likely a typo and they intended SBab/P which is what Seligman says for its classification.

It is messed up in another way having nothing to do with its condition. It carries three NGC numbers, NGC 6667, NGC 6668 and NGC 6678. Normally this is due to independent discoveries by three different astronomers, each giving somewhat different coordinates causing Dreyer to enter it under the different numbers. In this case, however, it was the same astronomer finding it three different times and not realizing it. The award for such sloppiness goes to Lewis Swift who found it on September 11, 1883 and listed by Dreyer as NGC 6667. Then again he found it on June 8 1885 and listed as NGC 6678. Finally he "found" it yet again nearly 14 months later on July 31, 1886 getting the designation NGC 6668. The second IC tries to equate it to NGC 6677 a degree to the south so that can't be right. Most think it a typo for 6667.

This galaxy is located in Draco. Redshift puts it at 115 million light-years but non-redshift measurements at NED all say it is at least about 130 million light-years distant with a median value of about 140 million light-years. I'll adopt this value for measuring its size. In my image, the plumes stretch some 5.67 minutes of arc. At that distance that is some 230,000 light-years. Though the main portion of the galaxy is only 1.6 minutes reducing it to a typical spiral size of 66,000 light-years before disruption by the merger.

Being far north and in the summer sky, it is in a poorly studied region. Only one other galaxy has redshift data and that is a faint starlike galaxy on the southern edge of my image at pixel 1372x1324 +/- about 5 pixels for those who absolutely have to find it. It is some 4.89 billion light-years distant and is listed as an AGN. The position is listed as being up to 5 seconds of arc in error. It is NEP 5750 for those wanting to look it up. That stands for the North Ecliptic Pole catalog if you were wondering.

The only other obvious galaxy in the image is the flat galaxy FGC 2208 southwest of NGC 6667. NED has no distance data on it. It is listed as an Sc galaxy. With nothing much to annotate, I didn't prepare an annotated image.

This was taken on a night of rather poor seeing that was unusually warm. That results in poor transparency and my being unable to reach my normal summer imaging temperature of -25C. I had to work at -15C which degrades the S/N slightly. I had just time enough for 5 luminance frames before the moon interfered too much. That extra frame brings the signal to noise ratio back to normal if transparency is normal which it wasn't so this one is still a bit noisy. For some reason, I never went back to retake it. However, due to conditions, I didn't take color data that night. I took color data a few nights later with better transparency but even worse seeing. Not sure if this was a good idea or not as the red data really suffered from seeing creating bloated stars that were a pain to deal with.

14" LX200R @ f/10, L=5x10' RGB=2x10', STL-11000XM, Paramount ME

Related Designations for NGC6667

NGC6670

NGC 6670 is a pair of interacting edge on galaxies. Though catalogs consider it a triple or even quadruple galaxy it is seen in a Hubble Space Telescope image to be just a pair of galaxies being torn apart and reassembled due to their interaction. You can read more about it at http://hubblesite.org/image/2295/news_release/2008-16 and see the Hubble image of this train wreck. Both galaxies are strong in HII emission though the eastern one is considered stronger in this respect. Oddly, it is the western one that is reddest in my image. Apparently, that comes from red stars rather than HII activity. NED classifies only the eastern member as a spiral. Though notes consider the small blue cloud at the far eastern end of the mess as being a blue compact however the HST image shows this to be in error. I never did figure out what those saying it is 4 galaxies are seeing as the fourth object. The only candidate is CGCG 301-032 to the southeast at the same redshift but it seems too far away to be the fourth member.

NGC 6670 is located in Draco at a distance of nearly 400 million light-years by redshift. Each is about 75,000 light-years across with the total projected size being about 125,000 light-years. It was discovered by Lewis Swift on July 31, 1886. It is in a part of the sky not covered by many surveys including the Sloan Digital Sky Survey so little information is available. What few are listed as galaxies at NED, with or without redshift data are listed in my annotated image. Many stars and galaxies are listed at NED simply as UvS for being an Ultraviolet Source. None with redshift data and all listed by approximate coordinates. These have a fairly large error circle making identification difficult in some areas. With many hundred listed, I only identified a handful of the brighter ones, all with the GALEXASC prefix.

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

Related Designations for NGC6670

NGC6677

There appears some debate over which galaxy is NGC 6677, NGC6679 and IC 4763. You can read all about it at http://cseligman.com/text/atlas/ngc66a.htm#6677 I didn't know of this issue as all of my sources, NED, SIMBAD, The Sky 6 Pro agreed with Seligman and made no mention of the issue. Because of this, the discovery dates of these is a bit confusing. I'm going with Seligman and saying all were discovered by Lewis Swift with NGC 6676 on May 30, 1886, NGC 6677 on June 8 1885 and NGC 6679 on October 25, 1885. IC 4763 is a prediscovery of NGC 6679 by Guillaume Bigourdan sometime in 1860.


All three are about 300 million light-years distant by redshift measurement though NGC 6676 has a slightly greater non-redshift distance at NED. All are in Draco.

There's another member of the group, PGC 062029. It too is about 300 million light-years distant. NED classifies it as Spherical though to me it is a spiral with a faint plume to the east off the north end. NGC 6679 is listed as a Compact galaxy which I can agree with. NGC 6677 is Sbc. A note at NED reads: "Peculiar spiral [UGC] of very blue color. Two (2) arcsec to the north is a pair of compact galaxies VII Zw 814." I find this odd as nearly everything seems wrong. While I see some blue in it it is mostly yellow-white rather than "very blue". While VII Zw 814 is the designation of NGC 6679 and PGC 062029 they are 2 minutes north not two seconds. It calls both compact galaxies. As mentioned I don't see PGC 062029 as being compact, but a Sa spiral with a plume.

I think it quite likely that all three have interacted in the past. It seems quite certain the northern two have and I see enough oddity in NGC 6677 to add it to the list.

Being so far north there's little else on the field. The only other galaxy with redshift data barely made it into my frame at the bottom, a 2 micron flat galaxy 2MFGC 14446 at 260 million light-years by redshift. The difference is small enough it too could be a member of the group Only one other galaxy shows detail so I included it in the annotated image even though it is just listed as a Uv source in NED with no distance data. Is it part of the group? I can only guess and say maybe.

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

Related Designations for NGC6677

NGC6683

NGC 6683 is a type I2p open cluster in Scutum about 2 degrees west of the far more interesting and famous M11 open cluster. This is another "What was I thinking about imaging this" cluster. While some turned out to be asterisms this one apparently is real. At least WEBDA has data on it unlike NGC 6840 and NGC 6843 I did earlier. WEBDA puts its distance as 3,900 light-years they say it is only reddened by about half a magnitude even though there's an obvious large dark dust cloud to the west and several other smaller ones right around it. They put its age at only 10 million years. That would likely mean nearly all its bright stars are blue having not yet aged enough to turn into red giants. Problem is, much of the field has blue stars in it. The only estimate of its size I found was "3.0? arcmin". That would limit it to the very center of my image. Problem is when John Herschel found it on July 28, 1827, he didn't see what I'm seeing. Dreyer condensed his description to "a cluster, very rich, little compressed (in the Milky Way)" Huh?

While the NGC Project is in the process of rebooting I found this comment on it at Dr. Corwin's personal website: "NGC 6683. I'm not quite sure just what JH was seeing here. His position is that of a small cluster of stars, yet his description is at odds with this: "A more than usually condensed portion of the enormous cluster of the Milky Way. The field has 200 or 300 stars in it at once." Looking at the DSS, a one-degree wide field shows clouds of stars defined by the many dust patches and lanes in the area, but none are centered exactly at JH's position. All that is eye-catchingly there is the small cluster. ...

"Consequently, realizing that this is not what JH meant to record, I've reluctantly adopted the little group as his object. This follows almost, but not quite, everyone else who has looked at this -- see Archinal and Hynes for modern data and aliases and Archinal's Webb Society Monograph for a more extensive discussion of earlier speculation." I didn't go digging further as he seems as lost as I am."

I note his notes assign it Trumpler class I2p which means it is easily separated from the background with strong central concentration, has a moderate range of brightness of the stars and has less than 50 stars. At least in my image, it doesn't seem to be well detached from the background but some mono images I found of it showing only the brightest stars do seem to fit its likely visual appearance. I've never looked at it visually. Steve Gottlieb's notes with an 8" scope from 1983 read: "10 faint stars in an elongated group over unresolved haze. The "Great Rift" is obvious just 10'W, in a rich field." That doesn't fit John Herschel's description but does seem to fit the little whatever I imaged.

You'd think open clusters would be simple and obvious. I'm finding that isn't always the case. Due to a lack of satellites, I saved time by only using one round of color images rather than my normal two as I was around to look at the subs as they came in and saw they had no satellites that needed dealing with. For that, I usually take two.

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

Related Designations for NGC6683

NGC6689

NGC 6689/90 is a near edge-on spiral galaxy in Draco. It is classified as SBcd with HII emission. It's distance isn't all that well determined. Redshift puts it only 18 million light-years away but readings that close are highly unreliable. Tully-Fisher estimates vary from 40 to 54 million light-years with a median value of 45 million which is also about the mean value. Adopting that distance it is about 57,000 light-years in diameter. It went on my to-do list due to its odd dust lane and the lack of much of a real hint of spiral structure. The dust lane seen in the side slightly toward us makes an odd almost V-shaped curve to the south then heads north cutting across what little spiral structure the galaxy has and vanishes off the top end rather than following the expected spiral pattern.

Notes at NED indicate it has a strange rotation curve. "Both sides of the rotation curve behave differently: the redshifted side has a solid body rotation curve, whereas the blueshifted side exhibits a plateau around 35 km s^-1^ up to 40 arcsec, then it increases again without ever reaching the redshifted side. There is no companion in the vicinity that could explain such an asymmetry in the rotation curve." Also, radio observations show the HI disk is strongly warped. So while no companion is seen it is likely there is one or a recently "digested" one. The digestion idea might explain the odd dust lane as well.

The galaxy has no hint of a bright core and I see little hint of a true central bulge. At first glance, the galaxy appears rather "normal" but when you look more closely it is quite odd indeed. I wish we could see it more face on.

The galaxy has the odd honor of being discovered 4 times by only 2 observers. Seems Heinrich d'Arrest found it first on August 22, 1863 then again sometime later. I can't find that date. While he didn't catch it was the same object the positions match. This results in it being listed as NGC 6689 by Dryer. Then on August 16, 1884 Lewis Swift made his first discovery of it. Later (again I can't find a date) he recorded it a second time with a position about 1 minute from that of his first discovery and the positions d'Arrest found. Dreyer caught that the first position was the same as d'Arrest but failed to realize the second position was in error and thus it went on the NGC as NGC 6690. I think it safe to say this second position isn't related to the unseen possible companion. You can read about this mix-up at the entries for either NGC entry at the NGC Project.

Since no other galaxy in the field had any redshift data at NED I didn't prepare an annotated image. This was taken on one of the rare good nights here this year. Even the fires out west kept their smoke out of my skies this night. I used to have skies like this regularly but the last two years they've been exceedingly rare I'm sorry to report.

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

Related Designations for NGC6689

NGC6691

NGC 6691 is a spiral galaxy located in Draco some 260 million light-years from us. Arp has a category in his atlas for 3 armed spirals. All three he included are really two-armed spirals with a major spur off one to make the third arm. Thus, I include this one as falling into the same category. It has two main arms coming off the bar and a large spur overlaying one of those arms that first goes north on the western side of the galaxy they a second spur comes off it going northeast. Much smaller spurs are seeing coming off the other arm. The galaxy to the south is listed in a note at NED as being a companion. This field is so poorly studied it has no catalog entry in NED. All other galaxies in the image that NED identifies are from the 2MASS IR catalog which only picks up galaxies bright in 2 micron IR radiation. The companion apparently doesn't have enough. It was discovered by Lewis Swift on August 16, 1884.

In the cropped and enlarged image, I've put NGC 6691 well off center to catch, in the opposite corner, two or maybe three galaxies. The two brightest are in the 2MASS catalog as 2MASX J18400484+5545142 and 2MASX J18400579+5545152. I can't tell for sure if the former is separate from the disk galaxy behind it or just a very bright core. I tend to think it is just another elliptical/S0 like the other one to the east and the disk object is a third galaxy whose core is mostly hidden by the 2MASS galaxy. NED is of no help here listing no size for either of the two galaxies.

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

Related Designations for NGC6691

NGC6700

NGC 6700 is a barred spiral galaxy in Lyra about 1.75 degrees southwest of M57 and about 200 million light-years distant by redshift and 260 million light-years by Tully-Fisher measurements. I measure its size at 107,000 to 140,000 light-years depending on which distance you believe. I put it on my list as in the POSS plates it looked rather unsymmetrical. That isn't as strong in my image, however. NED classifies it as SB(rs)c while the NGC project doesn't show the ring structure saying SBc. Seligman loves question marks so says SBc?. It was discovered by Édouard Stephan on August 17, 1873. While there are a few faint background galaxies in the image none had redshift data. With nothing but coordinates for a name and not even a magnitude I didn't annotate the image.

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

Related Designations for NGC6700

NGC6704

NGC 6704 is a rarely imaged open cluster in Scutum. This may be because it is only one degree north of the far glitzier M11. Also, it is located on the outskirts of Barnard 111 where extinction from the dust greatly dims and reddens the stars by about a factor of about 2. M11 is out of this reddening dust. WEBDA lists it as being some 9,700 light-years distant. They give its age as about 70 to 75 million years. For comparison, M11 is listed by WEBDA as being 6100 light-years distant so much closer but also older at 200 million years. Most sources list NGC 6704 as being about 6? minutes across which, ignoring the question mark, makes it about 17 light-years across. It is classified as Trumpler I3m. I=strongly separated from background stars; 3=wide range of star brightness and m=medium rich in stars. M11 (NGC 6705) is I2r for less range in star brightness but rich in stars compared to NGC 6704. The cluster was discovered by August Winnecke on July 23, 1854 using a 3" Merz refractor.

Due to the lack of needed resolution, I'm posting this one at 1.5" per pixel rather than my usual 1" per pixel image scale.

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

Related Designations for NGC6704

NGC6712

This field in Scutum fascinated me from the first time I saw it in my 10" scope nearly 50 years ago. The Skelnate Pleso 1950 atlas was the bible of the time and showed both objects. But I could only see one. It was just a small, faint puff of light. The problem was which object was it. I had no access to any observing reports or magnitude estimates back then. I figured I was seeing NGC 6712, the globular but it wasn't until years later when blinking the field with the Lumicon UGC filter showed me the planetary IC 1295. After that, I could see it, barely, without the filter. Doubt I'd have ever spotted it without the filter however. Seeing was poor the night I took this. It is on the reshoot list but so far that hasn't happened so I am going with this poor data.

NGC 6712:
Discovered by Le Gentil in 1749. He described it as a "true nebula" rather than a star cluster like the nearby M11. In 1784 William Herschel "rediscovered" it and again described it as a round nebula. It wasn't until nearly 50 years later his son John finally saw it as a globular star cluster. The cluster is about 23,000 light-years away. It is thought that due to its orbit carrying it within 1000 light-years of the Milky Way's core, it is being stripped of stars each passage.
http://arxiv.org/abs/astro-ph/9811173

While it still contains some million stars it must have been far larger billions of years ago. We see it through the dense Scutum star cloud so it is severely dimmed by the dust in the cloud. I expect it would be spectacular if we could see it in the clear.

IC 1295:
Information on this object is hard to come by. The central star is listed as being 15th magnitude but appears far fainter to me. I'm assuming its the faint blue star at the center rather than the brighter off center stars. My blue data shows a strong ring edging the faint outer shell. It didn't register in the luminance image so is lost in my color image. Next time, if there is one, I'll take a bunch of blue images and see if using it as the luminance layer will help bring it out. Other than that narrow ring the nebula has no fine detail, showing just a double shell with a fainter center. I was able to find only one distance estimate by a grad student in the Georgia State University Astronomy department siting a paper by Cahn et al put it about 1300 light-years distant, thus in front of the star cloud that so dims NGC 6712. The nebula was first seen by Truman Safford on August 29, 1867.

14" LX200R @ f/10, L=4x10' RGB=2x10x3, STL-11000XM, Paramount ME

Related Designations for NGC6712