NGC5970

NGC 5970 is a nice spiral galaxy in Serpens Caput. It is classified by NED as SB(r)c; HII LINER. It is some 90 to 100 million light-years distant depending on the source. I measure it at about 76,000 light-years across its longest dimension. I used 92 million light-years for a distance as that was a distance that best fit the various distance I found weighting toward the modern when a date was available.

I put it on the list as it was in the second Herschel Observing Program. I've put all those I can reach on the to-do list with the better ones getting a higher priority. Why this one waited so long to be taken I don't know but it may never have been in position when the weather cooperated until now. William Herschel found it on March 15, 1784.

It is listed as having two companions in several sources but doesn't list them. If PGC 055664 to the northwest is one of them then it's not a companion being 5 times more distant. IC 1131 has a slightly larger redshift but close enough to be a true companion given the error bars in using cosmological redshift for a distance measurement. Most sources do consider it a companion. It was discovered by Stephane Javelle on June 29, 1891.

The rest of the field is rather typical but again limited by very poor transparency which cost me over one magnitude worth of faint fuzzies. One though caught my attention. It is the quasar at 0.411 light-years in the lower right corner. It's PSF doesn't fit that of nearby stars indicating it is a bit larger than a point source. Not by much so a local seeing glitch could be to blame but it also could be I'm barely seeing the galaxy housing it as well or at least part of its core. There were no asteroids in the imaging area that I picked up. The field is 30 degrees from the ecliptic so this isn't surprising.

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

Rick

Related Designations for NGC5970

NGC5972

As most know by now I like to go where most amateurs fear to tread. Back in the fall of 2008, it was announced that a Dutch school teacher, Hanny van Arkel, looking at Galaxy Zoo images saw something odd. Hundreds had looked at the same image before her but she was the only one to wonder "What's that?" and post the question. It turned out to be a green object outside the obscure galaxy, IC 2497. It was bright green though on the Sloan images it was blue. At the time it was a mystery. Fortunately, the moon was out of the sky and it was well placed so I gave it a try to see if I could pull it out. Digital imaging was still new to me and I wanted to test its limits. It turned out to be relatively easy, not a difficult test after all. Still, it became the first amateur image of it as far as I and Hanny could determine. A check of Google images fails to turn up an amateur image of it even now. Though it misses many posted to Flickr and the like. Still, it surprises me a unique but rather easily imaged object is so ignored by most amateur imagers. It was later determined to be a cloud of mostly ionized oxygen illuminated by a now faded QSO in the heart of the galaxy, possibly left over from something IC 2497 digested. Were there others? Galaxies devour their kind constantly so it seemed likely.

Back in April 2015, the HST group announced they had found similar objects lit by a few other galaxies now vanished quasars so it wasn't unique after all, just very rare. One of their discoveries, NGC 5972, was well placed in my sky in late May so I had to give it a try. Like Hanny's Voorwerp (voorwerp is Dutch for "object") these are green. Due to late May skies allowing me only time for one of my typical 100 minute image runs in dark skies I took one round of data on it. I expected more would be needed as this is much fainter than Hanny's Voorwerp. I was wrong. I may not have HST resolution but much of the green object is seen. Yet again it wasn't as difficult as I expected.

It is thought these are gas clouds lit by light echoes of long-faded quasars in the heart of these galaxies. I am guessing they are blue in the Sloan image because those include ultraviolet mapped to deep blue along with blue mapped to a lighter blue. This Uv light may be stronger than the green or blue causing the color shift. In my pure LRGB image, the green is the natural result even after I subtract green from airglow I have in my images. The green is apparently due to OIII shifted by cosmological redshift from its normal teal to green. The shift is too great to allow standard OIII filters to be used on these so I've not attempted that.

You can read more about these Voorwerpjes (Dutch for "objects") at http://www.skyandtelescope.com/astronomy-news/hubble-finds-ghosts-of-quasars-past-042215234/

Redshift puts the galaxy about 410 million light-years distant. HST data says a 40" filament is 75,000 light-years long at the distance to NGC 5972. That works out to a distance of just under 390 million light-years. A rather good agreement as these distances go. Using the HST distance I get a size of 166,000 light-years for the galaxy including the small puff of green just south of the galaxy. The galaxy was discovered by Édouard Stephan on June 29, 1880. It is listed as S0-a or S0/a depending on the source.

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

Related Designations for NGC5972

NGC5981

NGC 5981, NGC 5982 and NGC 5985, right to left, are usually known as the "Draco Triplet" though there are other triples in the constellation these are the brightest. This was a very early image when I had little skill in digital imaging as my 50 years of film work didn't prepare me well for this new mode. The quality of the image is very poor for the quality of the night it was taken. I didn't do research nor even have software to annotate an image. Fortunately, these three are all of major interest in the image.

They aren't as related as they appear to be. NGC 5985 is a barred spiral about 110 million light years away, NGC 5982 an E3 Elliptical galaxy about 130 million light years out and NGC 5981 is an edge on spiral, like NGC 5746 above but with the normal ball-shaped core region. It is the smallest in apparent size. That might make you think it the most distant but actually its the closest as about 80 million light years. Thus it is also, by far, the smallest of the three. Notice how much smaller it is than giant NGC 5746 above yet that galaxy is 25% farther away. Not much on the net of these guys but lots of photos by other amateurs.

NGC 5981 was found by George Stoney on May 6, 1850. The other two were found much earlier by William Herschel on May 25, 1788. NGC 5985 is in the second H400 program. NGC 5982 is in the original program. My notes from my entry on May 18, 1985 with my 10" f/5 on a humid night at 120x read: "Small, round galaxy with a bright core that's nearly but not quite starlike. It's large neighbor, NGC 5985, is more interesting so why isn't it in this program?" Guess it had to wait for the second version.

Being a very early image I didn't do any research on this one. I just wrote this for the web and will do a good version, with a much better image, as time allows.

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

Related Designations for NGC5981

NGC5987

Besides Arp galaxies on my to-do list, I have a bunch I call Arp wanna-be galaxies. They didn't make his list but could have. Sometimes they fit his categories, sometimes they need one of their own or fit his rather small miscellaneous class. This is one of the latter in my opinion.

NGC 5987 has a rather odd system of dust lanes. There's one that is nearly straight that runs across the bottom much like a similar one in M63. M63's lane leads to a dwarf galaxy west of the main part of M63 though real deep images show the galaxy going as far as the little dwarf which it may be devouring. The dust lane might have been caused by the dwarf. In the case of NGC 5987, there's no related dwarf that I can find. There's another linear dust lane that joins the long one and appears to head to the back side of the core. One linear lane is hard enough to explain, a second that joins it seems a real mystery. Yet I find nothing about this in the literature.

NGC 5987 is classed as an Sb spiral by NED and the NGC project. It is about 140 million light-years distant in the constellation of Draco. It was discovered by William Herschel on May 25, 1788. It isn't in either of the Herschel 400 programs.

As usual, there are many distant background galaxies. I've prepared an annotated image showing the Quasars (Q) and Galaxies (G) and their distance in billions of light-years. I have no idea why some galaxies have this data and others don't. Even more of a mystery are two spindle galaxies, both oriented north and south near the eastern edge. They are on opposite sides of a distant, faint, spherical galaxy at 4.4 billion light years. Yet these two much brighter galaxies not only don't have any redshift data, I couldn't find them in any catalog at NED or SIMBAD! I've identified them with a question mark. The bright blob on the bottom right of center is just a bright star I didn't know how to deal with years ago.

14" LX200R @ f/10, L=6x10' RGB=3x10x3', STL-11000XM, Paramount ME

Related Designations for NGC5987

NGC5992

KPG 471 is a pair of galaxies in eastern Bootes near the border with Hercules that lie about 430 to 440 million light-years from us. The two carry the NGC numbers of 5992 and 5993. NED has a note indicating they are non-interacting. Odd as both seem rather disturbed to my eye. Also, I think I see a faint star stream running between them in my image as well as in the Sloan image of this pair. So I'm going to say they are interacting. NGC 5992 to the south is listed as SBb with HII regions. They are obvious with three forming a tight arc to the east of the core and several more looking like a distorted spiral arm on the western side. While it looks highly disrupted, I found no mention of this. It is a Markarian blue galaxy being #489 in his list of galaxies with excess blue and UV light coming from their cores. While it was the core that was important most are quite blue everywhere and often they are rather disorganized so NGC 5992 would be a classic example of his class of galaxies. Including plumes, its east/west diameter is about 160,000 light-years though its north-south diameter, lacking plumes is 122,000 light-years. It was discovered by William Herschel on March 18, 1787.

NGC 5993, at first glance, appears to have a dual core. These are just stars though NED lists the northwestern one as a galaxy at about the same redshift as NGC 5933, ASK 245893.0. Even though it is round and starlike they give a 1.02'x.59' size. They get the magnitude of 14.4 correct. The other star is listed as a star. The real core is rather hard to see with these two bright stars but is closer to the northwestern star. It is classified as SB(r)b:. Including the long extended arm to the north and the brightest plume to the south, its diameter is 250,000 light-years. Without these, it is half this size. It was also discovered by William Herschel the same night as he saw NGC 5992, March 18, 1787. Neither are in either Herschel 400 observing list.

To the east of NGC 5993 is an object I've labeled [SP82] 52 which NED lists as a blue compact galaxy but an essential note says "May be an outlying HII region or companion to NGC 5993." It seems to have some faint star clouds around it, especially to the west. So I vote that it is a blue compact galaxy. It may have been somewhat disrupted by NGC 5993 and or NGC 5992.

In the lower left is an object that is somewhat elongated, certainly not starlike that is listed in NED as SDSS J154551.14+405641.1 a quasar and as [VCV2006] J154551.2+405640, a galaxy. Usually, a quasar so outshines the host galaxy the galaxy isn't seen. They do list this as a candidate BLAGN (Broad Line AGN). Most quasars are broad line AGNs. But if it is one why is it so dim? It is closer to us than nearly all known quasars. So it may be a dying quasar. None seem to exist in our present universe. It's only when we look back in time they become common, They seem to have all died out by about 2 billion years ago though one is known at only a half billion light-years it is a very weak one in which the host galaxy is easily seen. It may be this one is running out of its food supply needed to keep up the output of a quasar.

Like most nights this fall and winter this wasn't a very good night. It started good and I took that opportunity to get luminance data but by the end of that period, the skies were going south. So much so I had to throw out the color data. I retook that a few nights later but conditions weren't much if any better. I forced these to work but consider the color balance as being rather questionable.

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

Related Designations for NGC5992

NGC6001

NGC 6001 is a face on spiral galaxy in Corona Borealis about 450 million light-years distant. To show this much detail at that distance it has to be a large galaxy. I measure it at a bit over 140,000 light-years across. It made my list as it fit into Arp's category for spirals with one heavy arm. While my nonlinear stretch sort of evens things out that arm is really much brighter than the rest of the disk. It has one other main arm that is much fainter plus a similarly bright spur that comes off the heavy arm making it appear much like a three-arm galaxy. Though the faint main arm has its own spur it is much fainter than the spur off the "heavy" arm. NED and the NGC Project classifies it as Sc while Seligman says Sc?

The galaxy seems to anchor its own "local group" of galaxies, all much smaller than it is. PGC 056051, sometimes called NGC 6002, being the nearest. If you scan the distances in the annotated image you'll find others at the distance scattered about the field. NGC 6001 was discovered by William Herschel on April 11, 1785. It didn't make either of the Herschel 400 observing programs.

This brings us to NGC 6002. Something was discovered by Lawrence Parsons on April 20, 1873. While sometimes identified as PGC 056051 that galaxy was likely too faint for even his 72" speculum mirror. There is nothing at his position southeast of NGC 6001. He was making a consistent 1-minute error that would move his position to south of NGC 6001 where again there's nothing. Thus some are tempted to identify it with the PGC galaxy to the southwest. His errors just can't make that work and that galaxy is fainter than anything he saw with the 72" speculum mirror. Though SIMBAD insists it is PGC 56051 many others disagree for the above reasons. What is within range and not far from his corrected position is the star I've marked in the annotated image. The Sky shows it to be a double star and does identify it as NGC 6002. NED says it is a star, making no mention it is double. Looking at the Sloan image I see no sign it is double either. Nor does its PSF in my image give any indication it is double. So I assume this is yet another problem with this object. PGC 056051 is classified as Sb? by Seligman.

Transparency was better than much of May but still below what used to pass for normal. There are some interesting background galaxies that appear to be interacting but they are too faint for me to bring out, unfortunately. Maybe if I ever retake this field I can catch them. I doubt that will happen, however. This is another taken near dawn without time for a second green frame. I saved green to last expecting dawn to be a problem. Fortunately, there are rather easy ways of compensating for weak or noisy green data so I never went back for a second green. One was sufficient.

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

Related Designations for NGC6001

NGC6004

NGC 6003 and 6004 are a pair of galaxies in Serpens Caput about 180 million light-years away by cosmological redshift. NGC 6003 is a rather dull, featureless compact S0-like galaxy. NGC 6004 is the interesting barred spiral galaxy. The two arms coming off the bar are very different. The one off the southern bar is quite normal looking starting right at the end of the bar and making a nice neat spiral out to the edge of the galaxy. The northern bar makes a sudden faint jog east to connect to the end of that spiral arm. The arm is more a collection of bright spots that quickly fades away into an amorphous blob part of which takes a jog west to almost connect to the far end of the southern arm. Arm segments are scattered about as well. Both galaxies were discovered by Édouard Stephan but on different nights. NGC 6003 was seen on June 19, 1879 while NGC 6004 was seen 5 days earlier on June 14, 1879. Being only about 15 minutes of arc apart his field of view must have been rather small.

Besides the normal assortment of background objects, galaxies, galaxy clusters and an asteroid there are two objects for which the data at NED seems to have been collected by that all too common astronomer Sum Ting Wong.

LEDA 4545108 is a rather amorphous looking galaxy to the west of NGC 6004. NED gives it a redshift of z=1.07681 which puts it some 8 billion light-years distant light travel time and some 824,000 light-years across using its apparent size distance of 5.54 billion light-years. No way this can be correct. NED also has an essential note on it saying one source puts the redshift at z=0.01299 which puts it only 177 million light-years distant and 26,000 light-years in size. Thus a dwarf companion of NGC 6003 and NGC 6004. Why NED gives the obviously wrong data the front and center position I don't know.

Then there's the similar case of ASK 560736.0 at the bottom left of my image. Again it has a redshift way out of line at z=1.532680. This puts its look back time at 9.5 billion years and a size using the angular size distance of 5.8 billion light-years of 842,000 light-years. Now that's one big edge on galaxy. Again an "essential note" gives a redshift of z=0.05267 for a distance of about 690,000 light-years and a size of 100,000 light-years. Again a far more reasonable result.

Between this last galaxy and NGC 6004 is another amorphous blob of a galaxy. NED lists it only as an ultraviolet source which it uses for some hot stars, quasars, and blue galaxies. Ned makes no determination of what the source is and provides little data. Blue objects like this often don't make it into NED from the Sloan data. Why this is I've not been able to find out. I've asked both NED and Sloan but never gotten a reply. I have several pro astronomers I've asked that study galaxies who have not a clue either.

May was a poor month for imaging with a lot of data lost to clouds. This is my last May object. June is difficult since it isn't dark very long. I usually need more than one night to catch an object. Still, it appears to have been a better month than May. Though I may find a lot of the data isn't usable when I go to process it. Guess we'll find out together how much is usable.

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

Related Designations for NGC6004

NGC6007

NGC 6007 is a rather strange looking spiral in Serpens Caput about 480 million light-years distant. The arm structure is quite unique, far from a classic grand design spiral. First off it is huge for a spiral at nearly 220,000 light-years in size. One main arm comes off the north side the core then makes a sudden turn around the core, goes straight for a bit then curves away getting broader and brighter as it goes. It's not obvious any other arm comes off the core. The only other "major" arm runs in a straight line above the core until it passes a field star with with another field star of similar brightness below it. The arm seems to know of these and hooks neatly around them ending just beyond the lower star. While the straight portion holds its brightness as it reaches the field star it fades away. Several other much shorter arm segments are seen including on that seems to come off the west end of this upper arm and which pretty much follows the same path, just further out though it has a curve rather than being straight. As it goes south it appears full of star knots that give it a someone kinky appearance bending first this way then that way. How did this huge galaxy get this way? I suppose it is due to interaction with other galaxies in the group, some of which it may be still digesting. There are many other galaxies at the same redshift in the field that appear as dwarfs by comparison but actually are rather large. NGC 6007 was discovered by Albert Marth on June 2, 1864, the same night as he found NGC 6006 and 6009 discussed below.

NGC 6006 is a rather strange galaxy, The NGC Project classifies it as E while Seligman classifies it as E3. NED says the rather cryptic "pair" which I included in the annotated image though I have no idea what this means. No one else sees two galaxies here, maybe NED doesn't either. I just don't know. If an elliptical it has plumes. Could this be due to interaction with NGC 6007 and help explain its odd arm structure. While it appears small it is actually a respectable 80,000 light-years across.

NGC 6009 is the other NGC galaxy in the field. NED doesn't attempt to classify it while The NGC Project and Seligman say simply S without further classification. Its upper arm does pull away from the disk slightly but otherwise, it is a rather basic spiral. I thought I saw hints of a bar but that may just be noise in my image. It is slightly larger of the little NGC galaxies at about 90,000 light-years in size, nearly as big as our galaxy. For some reason, a single Tully-Fisher distance estimate has it at nearly 160% the redshift distance. That would make it huge which seems unlikely so I'm going with the redshift distance.

Near the top of the image left of center is ASK 635335.0, another member of the group. NED shows the slightly blue object in the disk as a distant quasar seen through the disk of the galaxy. Since it is a spectroscopic redshift measurement that puts it over 10 billion light-years distant I'll have to say it is most likely the case but it sure looks like a blue star cloud in the galaxy to me. How bright is it to shine through the dust and gas of the galaxy?

To the east of it is PGC 056336 an SB(s)b? pec starburst galaxy with two wide arms. NED shows the bright parts of the north and south arms as separate galaxies, not as part of the galaxy as they seem to be. I didn't label them as the redshifts were virtually the same as for PGC 056336.

Below PGC 056336 near the bottom is another very wide two armed spiral. It appears to have a bright object on the end of a drawn-out east arm. Unfortunately, I'd had a camera problem before starting this image and had to dismount the camera then remount it. In doing so I failed to get it on square and didn't notice so this side of the frame is out of focus. Looking at the Sloan image of this object it is very blue and highly distorted as it whatever it was has been disrupted. Thus it may be the cause of the arm's length and drawn out shape. I'll need to retake this one with the camera square this time.

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

Related Designations for NGC6007

NGC6012

NGC 6012 is a very weird looking barred spiral in Serpens Caput about 90 million light-years distant. The NGC project classifies it as SBa while NED using a more complex classification system says (R)SB(r)ab: LINER: They indicate it may have a LINER core which could mean a somewhat active feeding black hole at its core though it may be due to white dwarfs in the galaxy. Note the colons are about the equivalent of question marks so there's some question about this. Assuming the 90 million light-year distance is correct it is about 85 thousand light years across. A respectable size for a barred spiral.

What drew my attention to it is the odd bright ring-like structure that appears could be a round ring seen foreshortened but since the galaxy is obviously seen nearly face on that would seem unlikely. The papers I found indicate the "ring" is caused by the bar (otherwise nearly invisible at visual wavelengths) which is outlined by bright stars creating the ring effect. These say the bar is well seen in K band IR images though I couldn't find any online. The DSS IR image shows some hint of the bar. I know of no other galaxy with a bright star outlined bar. I would have thought its appearance strange enough for Arp's atlas under his miscellaneous category but apparently, it didn't make the cut. NGC 6012 was discovered by William Herschel on March 19, 1787. It isn't in either H400 program.

While NED shows thousands of background galaxies none in my frame have redshift data but for NGC 6012. Therefore I haven't bothered with an annotated image.

14" LX200R @ f/10, L=6x10' RGB=2x10' (color and two luminance images taken a month later due to clouds with blue hurt by dawn and a bright moon), STL-11000XM, Paramount ME

Related Designations for NGC6012

NGC6015

I've heard of a cometary nebula, and have some on my to-do list in fact, but I've never heard of the term "cometary galaxy". If there is such a thing it is in this image. There is a very distant galaxy found by the HST that is now called the "Comet Galaxy" (http://www.spacetelescope.org/images/heic0705a/ in the upper left corner) but it is a far poorer "comet" than the one in this image. More on it in a bit. First some on the rest of the image.

NGC 6015 is a multi-armed, warped spiral galaxy in Draco, south of the bowl of the Little Dipper. Its distance is hard to pin down. Too close for redshift to be reliable other methods need be used. Tully-Fisher measurements range from about 50 million light-years to 66 million light-years though most cluster toward the lower estimate, say 55 million light-years. Oddly the highest and lowest measurements have the smallest error bar yet neither include the other. They are just too far apart. It was discovered by William Herschel on June 2, 1788. It is in the second Herschel 400 program.

Papers on this galaxy are also somewhat in disagreement, one finding a strong ring structure and another saying they couldn't find one. Though that one looked at CO radio frequencies while the one finding a ring used a wider range of frequencies. That paper goes into a lot of detail on this galaxy. It's abstract is at http://adsabs.harvard.edu/abs/1997A%26A...321..754V with a link to the free full article. The galaxy has no obvious central bulge.

The smudge of a galaxy off the eastern edge of the galaxy is SDSS J155136.52+621728.6. NED has no redshift data for it. I'd think it likely related to NGC 6015 but that is only a guess until more is known about it.

To the east of NGC 6015 is a very odd galaxy. It looks just like a comet! Since it shows up on the POSS plates dating back to the 1950's it is one slow comet! I would love to tell you about it. NED says it doesn't exist! It shows nothing at the position. NED does show the reddish spherical galaxy above it as the IR source 2MASXi J1552150+621928/SDSS J155215.07+621927.8. Between the IR galaxy and the comet-like one, NED shows a 23rd magnitude point source galaxy which on the Sloan plate shows up as a bright green hot pixel but they show nothing for the position of the comet-like galaxy. Did they fall for it being a comet? I can't fathom any other reason for leaving it out. The Sky 6 shows it as PGC 2634580 and 17.8 magnitude. In case it was a nebula in our galaxy I checked SIMBAD but it too has nothing at that location either. I found a 2007 post on a Yahoo forum saying SIMBAD did give it the same PGC designation as The Sky 6, however, I couldn't get SIMBAD to do so today. Maybe I don't hold my tongue right.

While this field is covered by the Sloan survey and NED shows at least 3000 galaxies in the field only NGC 6015 has any redshift data. Since I went with a non-redshift distance estimate I put it in parentheses. The image is full of interesting galaxy groups and clusters. Some of these did have redshift data. I was half done with the annotated image when I realized I wasn't picking up any galaxies. So I finished it, skimpy as it is.

May 2011 was a very poor month. This is my last May object. So I'm now only 13.5 months behind!

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

Related Designations for NGC6015