NGC672

NGC 672/UGC 1256 (north left of center) and IC 1727/UGC 1249 are an interesting, nearby, pair of galaxies in Triangulum. The red-shift distances are highly unreliable saying they are only 7 and 3 million light-years away respectively. This can't be true. Other distance measurements at NED put the distance to NGC 672 in the range of 23 to 32 million light-years and that of IC 1724 between 21 and 23 million light-years. Adam Block while at NOAO put the distance to both at 18 million light-years which is the distance cited in the paper quoted below though it gives 15 million light-years for IC 1727. Most sources consider them as interacting so the true distance to both should be close to the same. Radio measurements show the HI clouds around these two galaxies to be contiguous, not just overlapping. I found this interesting note at NED:

"UGC 1256 In this SB(s)cd spiral companion of UGC 1249, the HII regions are arranged along a bar in the inner parts and seem to draw a weak spiral structure around it. For this late type galaxy, no clear nucleus can be seen on the continuum map which shows several knots in the central part. The rotation curve, like that of its neighbor UGC 1249, is irregular, notably in the inner parts where it shows a counter-rotation motion. Indeed, one can see an inversion of the sign of the velocities within 20 arcsec of the center, corresponding to two HII regions (that surrounded by the isovelocity 420 and that on its right), with a symmetric behaviour for both sides of the rotation curve. The center of rotation has been chosen in order to have the two sides of the rotation curve symmetrical, but we want to underline the fact that this peculiar motion of counter-rotation persists if we choose another knot as the center, showing that this motion is real. The curve begins to be fairly symmetric beyond 100 arcsec (3.9 kpc), seeming to reach a plateau around 80 km s^-1^. However, according to the HI data, the plateau could be around 120 km s^-1^. Unlike what Carozzi-Meysonnier (1982) claimed (namely that UGC 1256 was less affected by the interaction according to optical studies), it is hard to estimate which galaxy is the more perturbed. Concerning its content in atomic hydrogen, the WHISP data show that its column density is very high in the optical disk (more than 20 x 10^20^ atoms cm^-2^), and that there is an extension of neutral gas to the north of the galaxy, which could be a tidal tail due to the interaction."

NGC 672 was discovered by William Herschel on October 26, 1786. It is in the second H400 observing program. Unfortunately my log for that never made the move to Minnesota for some reason.

For IC 1727 it says:
"This SB(s)m galaxy exhibits an asymmetric structure on the DSS image also observed on the Ha emission, which is mainly localized in what looks like a central bar and on the north-west side, suggesting a distorted spiral arm. No clear nucleus was detected on the continuum map and the center of rotation was chosen in order to derive the most regular and symmetric rotation curve possible. This rotation curve is quite chaotic but it seems that (from the approaching side) we reach a plateau at 70 km s-1 beyond 130 arcsec (2.8 kpc). About 9 arcmin to the north-east, UGC 1249 has a companion, UGC 1256, with which it seems to be interacting. Indeed, on the HI map derived by WHISP, one can see that their HI disks are contiguous and their velocity fields are regular and show a continuity in the isovelocity lines. The amplitude of the HI velocity field is in agreement with that derived by GHASP, confirming that we reach a plateau on the approaching side. "
http://adsabs.harvard.edu/cgi-bin/bib_query?2003A%26A...399...51G

IC 1727 was discovered by Isaac Roberts on November 29, 1896.

Only three other galaxies in the frame have redshift data and one of those is nearly off the frame. The pair of galaxies along the north edge toward the left corner are CGCG 482-017 at about 480 million light-years. The remaining galaxy is also at 480 million light-years. It is very small and faint. For those who want to track it down it is at pixel 123x954 near the left edge below center. The only "bright" galaxy in the image beside NGC 672 and IC 1727 is LEDA 1803573. It is the orange spindle just east (left) of the south end of IC 1727. NED had no redshift data for it. It is obviously a background galaxy.

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

Related Designations for NGC672

NGC6742

NGC 6742 is a small planetary in Draco. It's also what you image when you key in the wrong NGC number before you go to bed. Turned out to be somewhat interesting anyway, just not what I intended. Though I can't find much on it. It has some interesting internal detail. The night was good so I should have been at 1x1 binning but I suppose I should be grateful I got anything considering my slip up when entering the target numbers. I've not even recorded it in my viewing log so doubt I've looked at it visually. So faint I doubt any of the detail is visible in my 10" visually. The central star is about 20th magnitude or fainter so certainly wouldn't be seen. The star on the west edge measures out at 15th magnitude and thus would be a challenge in that scope as well. It was discovered by William Herschel on July 8, 1788. It isn't in either H400 program.

There's a small fuzz patch right next to its northeastern limb. Is it part of the nebula or an anonymous background galaxy? Probably the latter. There are dozens of faint background galaxies in the image if you go looking for them. I couldn't locate any distance data for NGC 6742.

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

Related Designations for NGC6742

NGC6745

NGC 6745 in Lyra was the first really strange galaxy I imaged back in 2007. I need to retake it as my imaging skills weren't up to the task. This one is the result of a two galaxy collision. The galaxies likely aren't going to merge. The little one to the north is fleeing the scene too rapidly to return. It was discovered by Édouard Stephan on July 24, 1879. While there are only two galaxies here, the main one and the little bullet that caused the damage, catalogs show three objects. As a result of the collision, a mass of new stars was formed about 10 million years ago. While the most massive have already lived and died in that "short" time many are still there. They are the blue northern tip of the lower galaxy and that carries its own PGC designation, PGC 200362 while the colliding galaxy to the north is PGC 200361 though the entire mess is NGC 6745.

You can see a picture of the main galaxy and the blue stars as taken by the Hubble Space Telescope at https://www.spacetelescope.org/images/opo0034a/ Only a small piece of the colliding galaxy is seen. Their image has south at the top while I put north at the top. A write-up of the image is at http://heritage.stsci.edu/2000/34/supplemental.html

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

Related Designations for NGC6745

NGC6749

NGC 6749 is another golden globular cluster (maybe) in Aquila that is seen through a lot of galactic dust that is dimming it by up to 4.5 magnitudes. Most consider it the most difficult NGC listed globular star cluster north of the celestial equator and second only to NGC 6830 at -39 degrees. It was discovered by John Herschel in 1827 with his 18.7" reflector. He described it as consisting of large and small stars. This is odd because I find no reports of any stars being seen it in with a modern 17" scope. But he also says it fills the field with stars. Considering it is only 3 minutes of arc across at most in a modern 17" scope it sounds like he was seeing field stars rather than actual members of the cluster.

It is also cataloged as Berkeley 42, an open star cluster. WEBDA just notes "May be a globular cluster." All other modern sources are confident it is a globular. I do find WEBDA's data conflicting with most other sources. For instance, they put it at 6000 light years from us while most other sources say 25,800 light-years, over 4 times more distant. WEBDA also gives it an age of 2.1 billion years. Old for an open cluster but too young for any other known globular cluster. They do have it cataloged as Berkeley 42 open cluster, not its NGC designation. SEDS gives it a size of 5.2 arc minutes. That would make it only 9 light-years across. Again, that doesn't fit a globular cluster. But at 25,800 it would be 39 light-years. Still small for a globular but considering the 4.5 magnitudes of extinction it is likely much larger than the 5.2 minutes cited. The long dimension, mostly north to south, in my image, is about 3.5 minutes across.

The Sky and others seem to list the position of Berkeley 42 a few minutes west and a bit south of the position for 6749. Sufficiently far that even the outer edges of NGC 6749 doesn't overlap the center position given for Berkeley 42. The Sky lists the two separately. Giving the position of NGC 6749 correctly and showing Berkeley 42 as being 2.6 minutes away at position angle 245 degrees. That would put it near the blue star at about 3:30 and one cluster diameter away. I see no cluster in the area other than the obvious one. Also in researching this, I found a paper, http://arxiv.org/pdf/astro-ph/0410325.pdf , from a Chinese Observatory that does consider it an open cluster with an age of 6 billion years. They make no mention it might be a globular cluster. I'd think that important. Maybe not. In all, I'm left "Lost in Space" without a robot to help me. Well not totally lost. The golden color is a good clue it likely is quite distant. That plus its size and star concentration heavily favor the globular cluster side as far as I'm concerned.

14" LX200R @ f/10, L=4x10' RGB=2x10' (hurt by clouds), STL-11000XM, Paramount ME.

Related Designations for NGC6749

NGC6760

NGC 6760 it a rarely imaged type IX globular cluster in Aquila about 24,100 light-years from us and 15,600 from the galactic center. It was discovered on March 30, 1845 by John Hind. The cluster's integrated spectral type is G5 so it is slightly yellow but reddening from looking through the disk of the galaxy has turned it much redder than it really is. Half the mass of the cluster lies within 1.27 minutes of its center though stars can go out nearly 13 minutes before tidal forces of the galaxy will rip them away. That would be more than halfway to the edges of the long dimension of my image. For such a nice globular it is surprisingly unknown. It is about magnitude 8.9 visually further adding to the mystery of its obscurity. In fact, checking my visual logs it appears I've ignored it like everyone else. I find no entry for it.

14" LX200R @ f/10, L=4x10' RGB=1x10' (clouds nailed color data), STL-11000XM, Paramount ME

Related Designations for NGC6760

NGC6764

NGC 6764 is a barred spiral in Cygnus only a couple minutes of arc from the border with Draco. It is about 100 million light-years distant by both redshift and the median of Tully-Fisher measurements at NED. That makes the galaxy about 86,000 light-years in diameter. NED classifies it as SB(s)bc;LINER Sy2, The NGC Project says SBb while Seligman says SBbc?. Reading a few papers on it some say it is a LINER galaxy, others say it is a Seyfert 2 galaxy, Some say it is both and some say neither. NED says both. Nearly all agree that the spectrum shows a lot of lines normally associated with Wolf Rayet stars, especially in the bar. They also say there's strong HII in the bar though I didn't pick that up. The galaxy was discovered by Lewis Swift on July 4, 1885. Too bad I didn't pick up the HII as if I had it might have been the "real" fireworks galaxy with that discovery date.

This part of the sky is in the Zone of Avoidance so there's little on it. Only two galaxies have any redshift data. The spiral toward the upper right corner is PGC 2387415 with a redshift distance of 480 million light-years. It is about 80,000 light-years in diameter The edge on spiral at the far left level with NGC 6764 is LEDA 2384950 at a distance of 580 million light-years. Look closely and you'll see it has a faint extension to the left as if it is a plume. This gives it a rather large size of nearly 200,000 light-years. Leave off the faint plumes and it is half that size. While there are many other interesting looking galaxies in the frame none have redshift data at NED. For that reason, I didn't prepare an annotated image.

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

Related Designations for NGC6764

NGC6765

NGC 6765 is one of Lyra's "other" planetary nebulae. It has many of them. While some planetary nebula looks similar to the blue-green ball of Neptune, hence their horribly wrong name many have very strange shapes. This is one of them. It is located 1.2 degrees northwest of M56. I found many distance measurements for it. A recent distance would be about 5000 light-years. That gives it a rather large diameter of about 2 light-years. It is considered to be in the early stages of interacting with the InterStellar Medium. For early stage, it sure looks messed up to me.

I believe its central star is the star just north of the tiny H alpha pink spot near its center. When that spot appeared I thought I had a glitch in my data but I've found a couple high-resolution images of this planetary that show it to be real. Strange but real. While I said H alpha it could well be NII emission or a combination. Someone with 3nm Ha and NII filters could answer this question but I don't have either and this is a pure LRGB image. It was discovered by Albert Marth on June 28, 1864.

If you look closely you'll see quite a few background galaxies, about 17 are listed in NED but some have coordinates with an error bar so large it is hard to pin them down. None listed in NED have even a magnitude let alone a distance estimate. Those with good coordinates come from the 2MASS catalog so miss those without strong 2 micron emission, that's most of them though most of the brightest and largest did make that catalog. Without any useful data and names that only are their coordinates and the vast number of stars making labels hard to read I didn't bother with an annotated image this time.

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

Related Designations for NGC6765

NGC6772

NGC 6772 is one of many planetary nebulae in Aquila. It is one of the better ones, at least photographically speaking. It was discovered by William Herschel on July 21, 1784. It is in the second H400 program. Unfortunately, my notes from that got lost in my move up here so I have no visual impression of it. Its parallelogram shape is rather unusual. It might be due to interaction with the interstellar medium but I didn't find anything on it. In fact, I found very little on it, not even a distance estimate.

This was a very early image of mine, even before I did any research. In fact, while I processed it, it was then lost on the hard drive for 11 years before I found it working on these pages.

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

Related Designations for NGC6772

NGC6781

NGC 6781 is one of the better planetary nebulae in Aquila. It was discovered by William Herschel on July 30, 1788. It is in the original H400 program. My log entry on May 21, 1985 with my 10" f/5 on a good night at up to 180x reads; "Large planetary nebula whose disk is somewhat brighter toward the north end. Dimmest toward the south end with an even dimmer center. No central star seen." CCD images don't match the eye because the eye is very sensitive to the cyan of OIII and the blue of hydrogen Beta but insensitive to deep reds from H alpha and NII lines common in planetary nebulae. So my visual impression likely is referring only to the OIII and maybe H beta lines, not the red rim.

Trying to find the distance to this nebula is a problem. Most places I've checked say it is about 2 minutes of arc across, 2,800 light years away and 2 light-years across. The problem is the math doesn't work. If you say it is 2 minutes of arc across and 2800 light years away then it is only 1.6 light years across. If it is 2 light years across and 2 minutes across it is about 3600 light years away. The three figures can't all be right. So your guess is as good as mine on its size and distance. I do agree it is about 2 minutes of arc across, I get 115" by my measurement, about 1.9 minutes.

The blue star in the center is the white dwarf that remains after it's red giant stage. The star has shrunk to about the size of the earth from a size large enough to hold millions of earths. It has no energy source other than a little bit from gravitational collapse as it cools. Still, it is so small it will live for billions of years. In fact, it's quite likely that every white dwarf ever formed is still in existence today. But that's not true of the nebula. Most only last 10,000 or so years. A blink of an eye in the life of the white dwarf. This is because it is expanding rapidly. In a few thousand years it will be so large and the gasses so thin and distant from the illuminating white dwarf it will just fade out of visibility. All planetary nebula seen in the universe are very young compared to the age of even the most short-lived stars.

This is another of my early 2007 images. My skills at processing and researching were nil back then. This will have to do for now.

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

Related Designations for NGC6781

NGC6786

NGC 6786 and UGC 11415 are a pair of interacting galaxies in eastern Draco just west of Tau Draconis which gave me fits and casts the nasty glare into the eastern side of my image. The pair is listed as VV414. They are about 340 million light-years distant by redshift and 350 million light-years away according to the HST website. This may be a rounding difference. The southern galaxy, NGC 6786. It is classified as an SB? Sy1 galaxy by NED and SBbc by the NGC project and SBbc? by Seligman. No one gave it a "pec" label. It was discovered by Lewis Swift on October 3, 1886. I measure its size as a bit over 100,000 light-years. That is helped by the drawing out of the arms due to interaction with UGC 11415. The CPCG says of it: "Distorted blue spiral, one pronounced and one washed-out arm." The UGC adds "Thin bright arm in direction of UGC 11415.

UGC 11415 is listed at NED as S? Sy2. Including the long arm to the north, it too is about 100,000 light-years in diameter. It is listed in the CPCG as a "Blue distorted spiral." While the UGC adds the adjective diffuse to that description. A blue field star makes seeing its core area details rather difficult at my resolution.

This pair has been imaged by the HST. Their take on them can be seen at: http://hubblesite.org/image/2289/news_release/2008-16 which shows a "little" more detail than I was able to capture.

Being far north and in the summer skies, these two were the only galaxies in NED with redshift values in the field. In fact, the rather large low surface brightness possible spiral south of the pair and third largest galaxy, in angular size, in the image isn't listed at NED at all except as an ultraviolet source (not a galaxy) as recorded by the GALEX satellite. It is LEDA 214717 according to SIMBAD and according to The Sky's database is listed at magnitude 18.4. I found nothing else on it. So no annotated image was prepared.

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

Related Designations for NGC6786