NGC3631

The supernova 2016bau was discovered by Ron Arbour in the galaxy Arp 27, also known as NGC 3631, on the night of March 13, 2016UT. The galaxy is located in Ursa Major about 60 to 70 million light-years from earth. I measure the supernova at magnitude 15.1. I originally took a picture of this galaxy in 2010. It is a type 1b supernova, a massive star that explodes long after losing its outer envelope of hydrogen.

I used a current two luminance frame image to get the SN and merged that into the 2010 image. The result isn't great but it will have to do. I can't get the SN to blow again for me.

LX200R @ f/10, LRGB=2x10' RGB=2x10' (L cut short by clouds), STL-11000XM Paramount ME

Related Designations for NGC3631

NGC3640

NGC 3640 is a very large elliptical galaxy in southeastern Leo about 77 million light-years from us. The ecliptic passes less than a degree away so I expected a lot of asteroids but only 5 were bright enough for me to point them out and most were barely bright enough. The sky was unusually bright with airglow limiting how faint I could go.

NGC 3640 appears rather disturbed, maybe by NGC 3641 just below it though redshift would argue otherwise. So do the two papers that mention the pair. Both look disturbed to my eye. NGC 3640 has faint plumes that spread in many directions. These may be due to galaxies it has already devoured. While I found papers on this galaxy none seemed interested in this aspect of it. One paper says NGC 3640 may have a faint tilted disk another says it is a fast oblate rotator. NGC 3641 seems to have been pulled in the direction of NGC 3460 but this is most likely an illusion due to the overlap of NGC 3640's outer region. Most papers I saw refer to it as a fairly regular elliptical. The bright region certainly is but beyond that lies a lot of faint red stars that give it a very irregular, almost lumpy appearance. To the northwest, it has a rather sharp cutoff with a faint hint of stars beyond. Other directions don't show this sharp edge but just fade away. This made determining its size difficult but setting an arbitrary level of 10 ADU above background I get a diameter of about 150,000 light-years. It varies a bit depending on what diameter you choose to measure but this is about the average.

NGC 3640 was discovered by William Herschel on February 23, 1784 and is in the original Herschel 400 program. It obviously didn't impress me visually as my log from a humid hurt night with my 10" f/5 on April 16, 1985 at 60 and 100 power is short and not very helpful. It reads "Small round galaxy, brighter toward the center." That may be my shortest entry of the 400. I was only seeing the bright central region. I'm sure the humidity is partly to blame but suspect I'd need a bigger scope to see much more no matter how good the night.

The other two NGC galaxies, NGC 3641 and NGC 3643 were discovered by Albert Marth on March 22, 1865. NGC 3641 was described as "faint, very small, almost stellar." NGC 3643 as "extremely faint, very small." He likely was only seeing the very cores of these.

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

Related Designations for NGC3640

NGC3646

NGC 3646 is a very peculiar spiral galaxy in Leo. Its inner spiral structure is that of a normal flocculent spiral but the outer structure is chaotic at best. One note at NED reads: "...The spiral pattern is very odd. One spiral arm emerges from the SE end of the inner disk and turns counterclockwise. Another emerges from the NW side of the inner disk and turns clockwise. These two arms appear to merge on the SW side of the galaxy, joining in a point. The arm structure on the west side is very well defined, and HSB, with many bright knots. On the east side, the arms are diffuse and patchy, with fewer knots. There is an LSB outer disk on the west side. The referee suggests, and we agree, that this may be an example of a galaxy with visible leading and trailing arms." I'm not sure I see the bi-directional arms but two certainly meet at a point on the southwest side.

Another note has a somewhat different view: "The morphology of NGC 3646 is peculiar, as if the result of an encounter. The outer spiral pattern cannot be traced even as to the sense of direction, but the inner spiral pattern is regular. NGC 3646 forms a physical pair with NGC 3649 (SBa; not in the RSA) at an angular separation of 8'. The redshifts from the catalog of Karachentsev (1987) are v_o(3646) = 4227 km/s and v_o(3649) = 4322 km/s. At the mean redshift distance of 85 Mpc (H = 50), the projected linear separation is 200 kpc. However, there is no indication of morphological distortion in the spiral pattern of NGC 3649. The peculiar outer ring structure in NGC 3646 here cannot be attributed to interaction with NGC 3649.

"NGC 3649 is much smaller in angular diameter than NGC 3646. The diameters are 80" for NGC 3649 and 260" for the outer ring of NGC 3646. Note that the inner part of NGC 3646 resembles a normal Sbc spiral of the same size as NGC 3649. The linear diameter of this inner part is 33 kpc - a normal value for most RSA spirals. However, the outer ring of NGC 3646 has a linear diameter of 107 kpc, which is abnormally large.

"The fact that the inner image of NGC 3646 has a normal morphology and is of normal size suggests that the ring is a result of a dynamical process such as the dropping of one galaxy through another, as postulated by Theys and Spiegel (1976, 1977) and by Lynds and Toomre (1976) in other ring galaxies. The abnormal velocity field and an early comment on the large linear diameter of the ring are given by Burbidge, Burbidge, and Prendergast (1961)."

HSB=High Surface Brightness, LSB=Low Surface Brightness, RSA=Revises Shapley-Ames Catalog of Bright Galaxies. A parsec is 3.26 light-years so a diameter of 107 kpc translates to almost 350 thousand light-years. But the article places it further away than today's estimates. At 210 million light years the diameter is about 265,000 light years, still very large.

I think the idea it is the result of some sort of interaction is quite likely correct. I wonder if a merger is involved rather than a collision as I find no bullet in the area. Also, there are some odd plumes. One to the southwest is just visible toward the orange star. Others come off the northeast side and are more easily seen. Maybe someone who can put dozens of hours into this one can find traces of looping plumes that would pretty well cinch the merger idea or not find them thus giving more weight to a fast interaction being the cause. NGC 3646 was discovered by William Herschel on February 15, 1784. It is in the second H400 program.

NGC 3649, while called a companion has a somewhat different redshift and appears rather normal. As the notes say, it is not interacting with NGC 3646 nor does it appear to have done so in the past. Redshift puts it at 240 million light-years while NGC 3646 has a redshift distance of 210 million light-years. Tully-Fisher distance estimates place it 174 to 203 million light-years away with the more modern measurements favoring the shorter distance. The pair are located in Leo. NED classes NGC 3646 as SA:(r)bc pec (ring). The NGC Project uses the simpler classification of Sc I. Irregular or peculiar it certainly is different yet one Arp didn't include. It would have fit his miscellaneous category, I'd think. NGC 3649 is classed SB(s)a by NED and S0 by the NGC project. I can't rationalize S0 for this obvious spiral galaxy. It has two sets of arms much like NGC 3646. One set tight to the core and outer arms that form a ring structure about it giving it a Saturn-like appearance. NGC 3649 was discovered by William Herschel the same February night as NGC 3646. It isn't in either H400 program.

The galaxy cluster at the top of my image, left of center has oddly differing redshift data for the cluster and the BCG anchoring it. Both are labeled as photographic which isn't as accurate as spectroscopic measurements. This may account for the difference. The cluster is WHL J112213.1+201752. NED shows it as containing 14 galaxies but gives no diameter. Toward the eastern side near the middle is another cluster with a different redshift (again both photographic) for the anchor galaxy. Though in this case the difference is small and not seen in the two significant digits I use for annotated images. That cluster is WHL J112242.1+200748 and has only 4 members in an undefined area.

While NED lists thousands of galaxies in my image except for these two cluster anchoring galaxies as well as the two NGC galaxies, none have redshift data. Hardly made the annotated image worth it. But I started it before discovering the lack of data. I'm including it anyway.

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

Related Designations for NGC3646

NGC3652

NGC 3675 is a beautiful but rarely imaged flocculent galaxy in Ursa Major. By redshift, it is about 46 million light-years distant. Other measurements, mostly Tully-Fisher, range from 41 to 65 million light-years. The one claimed to be most accurate in a 2009 paper says 54 million light-years. I found little agreement beyond this. It is classed as SA(s)b;HII LINER. I'm a bit puzzled over the HII as the only note at NED mentioning HII said the regions were less than 2" across and indicated they considered them a minor feature. It is tilted rather strongly toward an edge on view. This means we see the dust lanes on the near side much better than those of the far side. In fact, the galaxy has a large halo that further hides the far side from view. I've applied considerable processing to this region to bring out detail usually hidden by the halo in the few images of this galaxy I found on the net. Even the Sloan Survey image has difficulty with detail of the far side. The core seems to have no real bulge. It even appears recessed as if the flocculent arms and dust lanes extend further above and below the disk's plane than does the core. This is likely an illusion due to my processing to bring out spiral structure right to the very center, but one I can't seem to shake.

My reason for imaging it is the odd outer dust lane on the east side as well as the extensive outer faint regions. Are they plumes? Most images fail to show the outer regions with many stopping at the dust band not even realizing it is a band rather than the edge of the galaxy yet it is bright enough to show color rather well.

It was discovered by William Herschel on January 14, 1788. It is in the original H400 program. My log for that dated May 4, 1984 on an excellent night with a 12.5" f/5 scope at up to 150x reads: " Interesting tilted spiral, much detail seen in the arms. Starlike nucleus. 11th magnitude. A very good object!!"

There's a really strange galaxy above NGC 3675. It is SDSS J112622.06+434124.4. It has one arm on the east side mostly detached from the core. There's nothing on it in the literature. I'd love to see what Hubble's view of it would be. There are several galaxy clusters in the image. The one due east of NGC 3675 is WHL J112649.0+433441. The BCG is listed at 4.05 billion light-years but the cluster with the same location has a photographically determined redshift of 4.25 billion light-years. I consider the former more likely the more reasonable estimate. To the west and a bit, north is the 22 member group WHL J112459.4+433810. Right near the northwest end of NGC 3675 is the small 7 member group WHL J112557.7+433919. Virtually my entire field is covered by ZwCl 1122.8+4351. It is listed as being 19 minutes across and containing 99 members. Its morphology is listed as open which means it lacks any pronounced concentration of galaxies. Yet another cluster is centered just off the east edge of my image. Several of its members are in the frame so I drew a line to indicate where the center is just a few pixels beyond the edge of the image. The cluster is GMBCG J171.91396+43.71478. The BCG is listed at 2.5 billion light-years with the cluster's photographic distance at 2.6. Again, the photographic determination is usually less accurate so I went with the 2.5 figure in the image.

The vast majority of galaxies in the field had no redshift values at NED. All that did are listed in the annotated image.

I see by the current Astronomy Magazine the term "flocculent galaxy" was coined by Debra Meloy Elmegreen the current president of the American Astronomical Society. I didn't realize it was such a new term. (Edit: This was written on July 2, 2012)

I've also included the Sloan Survey image of this galaxy. It was the only image I found on the net that indicated there was more to the galaxy than all the other images I found were showing.

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

Related Designations for NGC3652

NGC3655

NGC 3655 is a near face-on spiral in the hindquarters of Leo the Lion about 83 to 99 million light-years from us. Though I found distances ranging from 45 to 125 million light-years. Determining distance to galaxies isn't easy. It was discovered by William Herschel on December 30, 1783. It is in the original H 400 program. My log from April 16, 1985 with my 10" f/5 on a humidity hurt night at 100x reads: "Very small, faint, evenly bright, round, puffball of a galaxy. It looks much like a planetary nebula without a central star. About 1' in diameter. Note the preliminary guide says it is in Ursa Major which is not correct." The galaxy has a foreground star east of the nucleus that in a low-resolution image fooled me into thinking it had a double core according to my notes of why I imaged it. The other reason being it is one of the H400 galaxies I can reach from my latitude but the mistaken double core likely pushed it higher in priority.

Turns out while the galaxy wasn't as interesting as I expected the field has some strange galaxies as well as interacting galaxies. To the lower left of NGC 3655 is ASK 623321.0. It has a strangely elongated spiral arm. To its upper right is what appears to be two interacting galaxies.

North of NGC 3655 is a pair of galaxies that may be interacting. Only ASK 625768.0 has a redshift value I could find. Are they just line of sight like the previous pair or actually interacting? I found nothing on them.

To the upper right of NGC 3655 is another possible pair of interacting galaxies. The pair is known as LEDA 1514261. They mark the core of a galaxy group. But while the group and ASK 623348.0 share the same coordinates NED places them over 1 billion light-years apart. The distance to the cluster is not spectroscopically based while that of the lone galaxy likely is. Could the photographically determined redshift be that much in error? There are obviously two other galaxies in this tight group. One an edge on galaxy and the other a slightly elongated elliptical galaxy between ASK 623348.0 and the edge-on galaxy. I couldn't find it in either NED or SIMBAD.

Near the left edge is an odd object. It is labeled SDSS J112353.72+163806.5 and SDSS J112352.97+163802.7. The Sloan image indicates the first is two objects, a small red oval galaxy and an elongated sliver of a galaxy. The west end of which carries the other ID given above. It may be a star cloud at the far end of the first galaxy or an entirely separate object. I tend to vote for the latter. But no redshift data leaves a lot of possibilities. The GALEX satellite saw this object but its resolution was low. It's hard to know what it was seeing. Its coordinates point to the low luminosity region between the two but the error circle is big enough to cover all objects here.

Below this object or objects is SDSS J112353.89+163701.2. If you look closely you can see it is surrounded by a much larger very faint fuzzy disk. The Sloan image shows it to have a very faint highly fragmented set of arms that make up the fuzz seen in my image.

Any of the Sloan images can be seen at any of many Sloan websites by entering the coordinates given by the name. Thus for SDSS J112353.89+163701.2 just enter the RA of 11 23 53.89 and declination of +16 37 01.1 and select an image scale. One page you can use is http://skyserver.sdss.org/dr9/en/tools/chart/chart.asp

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

Related Designations for NGC3655

NGC3675

NGC 3675 is a beautiful but rarely imaged flocculent galaxy in Ursa Major. By redshift it is about 46 million light-years distant. Other measurements, mostly Tully-Fisher, range from 41 to 65 million light-years. The one claimed to be most accurate in a 2009 paper says 54 million light-years. I found little agreement beyond this. It is classed as SA(s)b;HII LINER. I'm a bit puzzled over the HII as the only note at NED mentioning HII said the regions were less than 2" across and indicated they considered them a minor feature. It is tilted rather strongly toward an edge on view. This means we see the dust lanes on the near side much better than those of the far side. In fact the galaxy has a large halo that further hides the far side from view. I've applied considerable processing to this region to bring out detail usually hidden by the halo in the few images of this galaxy I found on the net. Even the Sloan Survey image has difficulty with detail of the far side. The core seems to have no real bulge. It even appears recessed as if the flocculent arms and dust lanes extend further above and below the disk's plane than does the core. This is likely an illusion due to my processing to bring out spiral structure right to the very center; but one I can't seem to shake.

My reason for imaging it is the odd outer dust lane on the east side as well as the extensive outer faint regions. Are they plumes? Most images fail to show the outer regions with many stopping at the dust band not even realizing it is a band rather than the edge of the galaxy yet it is bright enough to show color rather well.

It was discovered by William Herschel on January 14, 1788. It is in the original H400 program. My log for that dated May 4, 1984 on an excellent night with a 12.5" f/5 scope at up to 150x reads: " Interesting tilted spiral, much detail seen in the arms. Starlike nucleus. 11th manigude. A very good object!!"

There's a really strange galaxy above NGC 3675. It is SDSS J112622.06+434124.4. It has one arm on the east side mostly detached from the core. There's nothing on it in the literature. I'd love to see what Hubble's view of it would be. There are several galaxy clusters in the image. The one due east of NGC 3675 is WHL J112649.0+433441. The BCG is listed at 4.05 billion light-years but the cluster with the same location has a photographically determined redshift of 4.25 billion light-years. I consider the former more likely the more reasonable estimate. To the west and a bit north is the 22 member group WHL J112459.4+433810. Right near the northwest end of NGC 3675 is the small 7 member group WHL J112557.7+433919. Virtually my entire field is covered by ZwCl 1122.8+4351. It is listed as being 19 minutes across and containing 99 members. It's morphology is listed as open which means it lacks any pronounced concentration of galaxies. Yet another cluster is centered just off the east edge of my image. Several of its members are in the frame so I drew a line to indicate where the center is just a few pixels beyond the edge of the image. The cluster is GMBCG J171.91396+43.71478. The BCG is listed at 2.5 billion light-years with the cluster's photographic distance at 2.6. Again, the photographic determination is usually less accurate so I went with the 2.5 figure in the image.

The vast majority of galaxies in the field had no redshift values at NED. All that did are listed in the annotated image.

I see by Astronomy Magazine the term "flocculent galaxy" was coined by Debra Meloy Elmegreen the current president of the American Astronomical Society. I didn't realize it was such a new term.

I've also included the Sloan Survey image of this galaxy. It was the only image I found on the net that indicated there was more to the galaxy than all the other images I found were showing.

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

Related Designations for NGC3675

NGC3683

NGC 3683 is a rather strange galaxy in the bowl of the Big Dipper. It's tilted dust lane is what first attracted me to this one. Later I realized it was in the Herschel 400 II observing program, another reason to be on the to-do list. I figured the odd dust lane is due to a merger with another galaxy or at least a close interaction with one. I found nothing in the literature even discussing this odd feature. It is noted in passing in over 100 papers but about the only ones giving it much time are those covering the supernova in 2004 that blew in the galaxy. But nothing on the odd dust lane that looks like it could be a polar ring or some other interaction result. Besides the tilted ring that seems to go up and over the northwest end of the galaxy there's dust lane at the southeast that also isn't aligned with the galaxy. This one runs more east-west than the galaxy does and quickly is lost when it goes off the galaxy's illuminated portion. Two interactions in its past. I found nothing on either. If anyone wants to dig through the more than 100 papers that mention the galaxy and finds something on this please let me know. I'm so short on time right now I can't spend as much time researching as I'd like.

To the upper right is NGC 3674 a mostly featureless S0 galaxy. I thought I had it totally in the frame but see it extended further than NED indicated so I missed its northeastern ansae. Both galaxies were discovered by William Herschel but only 3683 is in either of the Astronomical League's observing programs. NGC 3683 was discovered first on March 18, 1790. NGC 3674 was discovered 3 years later on April 8, 1793.

There is a difference between redshift measurements and Tully-Fisher distance measurements. Redshift says 87 million light-years while Tully-Fisher says about 99 million light-years. By Redshift, I measure its size at about 55,600 light-years. By Tully-Fisher it is somewhat larger, about 63,300 light-years in size. Either way, it is a rather typically sized spiral galaxy. NGC 3674, whose redshift distance matches the Tully-Fisher distance to 3683 comes in at 45,600 light-years in size. I had to assume the northeast half of the galaxy is the same size as the southwest due to my framing error.

Below NGC 3683 is a quasar labeled FSRQ. That stands for Flat-Spectrum Radio Quasar. These may be similar or even identical to BL-Lac objects. They aren't all that common, at least at NED.

A distant galaxy with a single drawn out arm lies to the west-southwest of NGC 3683. It is ASK 296263.0. Opposite the arm is a galaxy. Unfortunately, I found nothing on it. Could it be what created that odd arm or is it just a coincidence? Below and to the right of it is a strange blue galaxy, LEDA 2548235. It is made of two parts. The position at NED matches the gap between the two parts. Also, NED has two very different redshift distances for it. One puts it 150 million light-years away and one referred to in an essential note puts it at 700 million light-years. I used to think the main redshift they give is more likely correct but recently I found one that appears to be wrong and the essential note distance is right. In this case, flip a coin. I tend to favor the closer distance. I wish there was distance data for the blue galaxy to its west. It has much the same color and likely is related. No redshift is published for it that I found. But again, due to time issues, I didn't look beyond NED. If someone finds something on it please let me know.

The blue star obliterating the lower left corner of the image is SAO 28035 a Magnitude 6.3 A4 star. I had one heck of a time convincing it to let me see much of the image. When I framed the field excluding it, it sent in a horrid ghost image and blue ring. I finally found this position that got rid of those but I see that cost a bit of NGC 3674. Hipparcos puts it at a distance of 221 light-years. I guess I should be glad it isn't closer.

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

Related Designations for NGC3683

NGC3686

NGC 3686 is a rather low contrast, face on spiral galaxy about 50 to 70 million light-years away in the hindquarters of Leo the Lion. The difference in distance depends on whether you go with the non-redshift or redshift distance determination. Usually, with nearby galaxies like this one I side with the non-redshift distance but I'm making an exception here. Three other spiral galaxies with similar redshift values are just out of the bottom of my image. Their non-redshift distances vary by nearly a factor of two but redshift values are quite similar. If related then they must be about the same distance. Hence I'm going with the redshift distance with is close the middle of all 4 galaxies non-redshift distances. I'd need to mosaic another frame to catch these which is on the to-do list but when it will happen I don't know. They are NGC 3681, NGC 3684 and 3691 all found by William Herschel with NGC 3681 being in the second Herschel 400 program.

This galaxy could have made Arp's peculiar galaxy atlas under its 3 armed spiral category. To my eye it is a better example than most of the 3 he listed in that cagegory.

NGC 3686 was discovered by William Herschel on March 14, 1784. It is in the original Herschel 400 program. My notes from that on the humidity limited night of April 16, 1985 using my 10" f/5 at 50x reads: "Large, oval galaxy that resembles a tilted featureless spiral with no nucleus seen. Also in the field are NGC 3684,3681 and 3691." Dreyer's description reads "pretty bright, large, very little extended, very gradually brighter middle, mottled but not resolved." Sounds like the humidity was hurting me more than I realized.

The annotated image shows a lot of galaxies at a distance of about 1.6 to 1.7 billion light-years scattered about the image. They seem more concentrated to the lower right. This is the center location of the Abell 1264 galaxy cluster which is large enough to cover my entire image even when centered to the lower right. Another cluster with only 13 members is north of NGC 3686 and a bit closer at 1.52 billion light-years. This however is a photographically determined distance that can be somewhat in error. Considering many of the galaxies with spectroscopically determined redshift around this point are at 1.64 billion light-years I have to wonder if this isn't just part of the Abell cluster Though there is one galaxy in the area with the 1.52 billion light-year distance.

Three asteroids are shown in the annotated image though one is so faint it nearly vanished due to the losses of JPG compression. A fourth is lost in NGC 3686 itself and listed at the same magnitude as the nearly vanished one. I can't be sure I'm seeing it so didn't include it. Transparency this night wasn't all that great making even the 17.6 magnitude asteroid on the far left fainter than it should be. I lost at least a half to .75 magnitudes over an average night.

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

Related Designations for NGC3686

NGC3724

When I imaged the USGC S171 galaxy group last April I had no idea what a can of worms I was opening. I looked up the group on a POSS server nothing odd was seen. When I brought it up in The Sky I decided to center on NGC 3724 so entered those coordinates. The scope dutifully imaged exactly what I expected. I processed the image and seeing it was in a little studied area had only a few galaxies to annotate. When I started in on that all hell broke loose. When I checked the NGC project for details on NGC 3724 it showed me an entirely different galaxy yet referred to NGC 3732 at the very bottom of my image. But nothing else made any sense at all. At least they gave an IC number for it as well (IC 2910). That took me to a galaxy almost 40 minutes beyond this field to the west. Now I was totally confused. Looking up NGC 3724 at NED showed the field and galaxy I'd taken but noted that NGC 3724's identity was uncertain. Oddly NED had no such "essential note" for NGC 3722 even though the NGC project again pointed to an entirely different galaxy two thirds of a degree west well out of my field of view. Then checking NGC 3730 I found it too was of uncertain identity yet both sources pointed to the same galaxy in this case. By this time I was breaking out the Jack Daniels and it was only mid-afternoon. For a lot more on this confusion see the entry for NGC 3724 at the NGC Project and their reasoning as to why they picked these other galaxies. Since I use NED as my standard source unless I have a strong reason otherwise I'll go with their identifications on the annotated image. But then I checked SIMBAD and found yet a different ID for these. What NED has for 3724 SIMBAD says is 3722 and vise versa. NGC 3730 at NED and NGC Project is NGC 3721 at SIMBAD. NED says 3721 is a galaxy just out of the top of my field while the NGC project puts it over near their version of NGC 3722 and 3724. Even a half dozen shots of Jack Daniels didn't help my aching brain. In any case, there's no uncertainty that this is the field for the center of USCG S171 whose center is marked on the annotated image.

Here's a table of the NGC galaxies at NED (N) then NGC Project (NP) then SIMBAD (S).

IC 2910(N) NGC 3724(NP), IC 2910(S)*
LEDA 170153(N), NGC 3722(NP), LEDA 170153(S)*
NGC 3721(N), NGC 3721(NP), NPM1G -09.0435(S)*
NGC 3722(N), na(NP), NGC 3724(S)
NGC 3724(N), na(NP), NGC 3722(S)
NGC 3730(N), NGC 3730(NP), NGC 3721(S)
NGC 3732(N)(NP)(S)
* not in my frame

NGC project covers only objects it considers NGC galaxies or IC galaxies. I use na to indicate the object isn't considered either by the project thus not covered.
In all cases, The Sky agrees with NED. I was too dizzy to check other sources.

This confusing field can be found in north-central Crater and is about 300 million light-years distant. IC 2910, the other NGC 3724 lies at about the same distance so is likely also part of the group though NED lists no size for it. Also the other NGC 3722 (LEDA 170153 according to NED, SIMBAD and The Sky) is also about this distance. This field is on my to-do list. Though at the time only because this other NGC 3724 is a nice peculiar galaxy. I had no idea of this can of worms when I put it on the list. The other NGC 3722 is nearby so will be in the field though I'd not thought about it when putting this area on the to-do list.

NGC 3722 and NGC 3724 in my image were discovered by Andrew Common in 1880 according to Corwin and Seligman yet when I look up NGC discoveries by Common neither is listed.

The other NGC 3722 and NGC 3724, as well as NGC 3730, were discovered by Francis Preserved Leavenworth in 1886. His list of NGC discoveries does include 3722 and 3724.

This leaves only one other NGC galaxy and this one has no issues except I didn't get it all in the frame. That is NGC 3732 rather ill-defined spiral or S0 galaxy that is much closer at about 88 million light-years. It was discovered by William Herschel who didn't mess up coordinates when he logged it on March 4, 1786. It is in the Herschel II 400 list. Since that wasn't the target my system chose it didn't bother to make sure it was in the frame even though it too was on the to-do list. I suppose I need to rewrite my script to check for such things in the future.

NGC 3722 is 82,000 light-years across
NGC 3724 is 120,000 light-years across
MCG-01-30-008 is 64,000 light-years across if the redshift distance is right.
2MFGC 09063 is 85,000 light-years across
NGC 3730 is 140,000 light-years across
NGC 3732 is only 30,000 light-years across
GSC 5509 00368 is lost behind a star so I can only estimate its size at 50,000 light-years.

Six asteroids are visible in the luminance FITs stack. A couple are very faint and might not make it in the highly compressed annotated image. Transparency was poor this night so even the brightest which would normally be nearly saturated is rather faint though its color traces can be seen.

Due to the conditions and how low this one is in my sky the color data is highly suspect. All attempts at normal color balance techniques (G2V, eXcalibrator) failed miserably turning in a highly red image. So I applied more a seat of the pants color balance. The result is highly suspect but the best I can come up with under the conditions. I couldn't find any color images of this area except pseudo color from red and blue POSS plates so I had to pretty much wing it. Basically, I used the brightest asteroid and equalized the three color traces. Probably wrong as I don't know the color of the asteroid. Many are red. In which case this one is red starved.

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

Related Designations for NGC3724

NGC3726

NGC 3726 is about 35 million light-years away in Ursa Major. It is part of a group of galaxies sometimes called the Ursa Major Cloud. M108 and M109 I've covered in the past are the brightest members of the group. It too appears to have tangled with something in the past as told by the strongly kinked arm at the "bottom" of the galaxy making it look very unsymmetrical. That arm shows strong new star formation with the many knots of blue stars. Who it tangled with in the past I haven't been able to find out.

It was discovered February 5, 1788 by William Herschel. It is in the original H400 observing program as it is a very good visual object. My entry from May 4, 1984 with a 12.5" f/6 scope from the New Mexico Bad Lands at 150x on an excellent night reads "Large, oval, a featureless puff, Getting evenly brighter toward the Nucleus. Seems about 12th magnitude due to its rather large disk spreading its light out so much rather than the 10.8 in the H400 preliminary pages or 11.3 in Burnham's." Obviously, I wasn't seeing the arms that are obvious in my image.

This is one of my very first color images processed with insufficient software and ignorance of how to us what it did allow me to do. Somehow it came out surprisingly well but likely would show more detail if I went back and reprocessed it. Just haven't had the time.

14" LX200R @ f/10, L=4x10' RGB=3x10' all binned 2x2, STL-11000XM, Paramount ME

Related Designations for NGC3726