NGC7769

this is a group of interacting galaxies, NGC 7769, NGC 7770, NGC 7771 and NGC 7771A. They are about 170 millions light years away. NGC 7769 is the face on spiral to the upper right. The other big galaxy is NGC 7771. It shows more tidal distortions than NGC 7769. These are likely caused by NGC 7770 just below it. It is a double nucleus S0 galaxy. It could be the result of the merger of two such galaxies whose cores haven't yet merged. I found one paper in which radio HI emissions were used to try and determine this but there was too much noise in the data and they couldn't come to a conclusion. Note how the tidal arm of 7770 that goes down, ends very suddenly. The bright arm at the top left of NGC 7771 also ends abruptly. Very odd. The blue galaxy between NGC 7769 and 7771 is NGC 7771A. It appears that the interaction has triggered a lot of star formation in it. There are a few dwarf members of this group but they are only easily seen when I leave the data very noisy so I won't try and point them out. Toward the top is the more distant Seyfert galaxy MCG+03-60-031 which is 550 million light years away. Oddly the rather bright and large galaxy below it and above the NGC 7769-71 group is not in either the SIMBAD or NED database. I've determined it is PGC 214992 but that's all I know about it. The PGC catalog has been replaced with LEDA using the same numbers yet it isn't in the LEDA database that I can find. NGC 7771A is LEDA 214993 but there is no LEDA 214992. It apparently isn't a member of the group. A supernova was seen in NGC 7771 in 2003. Not unusual for tidally interacting galaxies. The interaction triggers star formation which tends to favor massive, short lived stars. Though this galaxy looks old by its reddish color.

NGC 7769 and NGC 7771 were found by William Herschel on September 18, 1784. Neither are in a Herschel 400 program. NGC 7770 was discovered by Bindon Stoney on November 5, 1850.

The vertical reddish galaxy trying to hide behind a bright star to the lower left is 2MASX J23515674+2001568 ID. I know nothing else about it. The galaxy further left and up by a bright double star is 2MASX J23522016+2005528 ID. Again that's all I have on it. I have even less on the obvious galaxy at the right edge of the image near the center. It appears to be a barred spiral but I couldn't find it in any database I have nor on any online database.

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

Related Designations for NGC7769

NGC7778

This NGC group in Pisces under the Great Square of Pegasus is located about 220 million light-years distant. All but NGC 7780 are members of the WBL 727 galaxy group. All 5 are members of the USGC U860 group. That group has two other members out of my frame, one to the south the other to the northwest.

I was only trying for the WBL 727 group so the rest are just lucky to make it into the frame. Especially FGC 2548 which was also on my to-do list but I'd not realized could be part of this image. I sometimes get lucky. It is better known as LEDA 091829. I was interested in the little red galaxy off its west ansa. Unfortunately, I can't find anything on it as it isn't in either NED or SIMBAD.

NGC 7782 is the only one large enough to show much detail. Notice how its spiral arms aren't connected to anything like a core. Also, it seems to have faint outer plumes regions to the north, south and east that may indicate it is still digesting another group member it ate in the past. In any case, it is very large. I get a size of 175,000 light-years including the plumes. Ignoring them it is still 115,000 light-years in size.

NGC 7778 is listed as an elliptical though one paper says it shows hints of spiral structure. NGC 7779 is a very fuzzy spiral, NGC 7781 has no detail at all and may be an S0 to my eye. It is the smallest member of the group at 55,000 light-years. NGC 7780 has some interesting spiral arms. Two may come from the core while two arcs appear to be bright extensions of these arms after they faded away. The southern one longer than the northern. It seems rather odd to me but didn't get a peculiar label.

NGC 7778, NGC 7779 and NGC 7782 were discovered by William Herschel on November 12, 1784.
NGC 7780 was found by Édouard Stephan on October 18, 1881. NGC 7781 was discovered by John Herschel on August 16, 1830.

There are a couple of distant galaxy clusters in the image. Neither have a cD galaxy so I've drawn a line to the center position which is rather vague in NED. One has an estimated distance, how that was estimated I have no idea as NED doesn't say. The Zwicky cluster has no distance at all. It is quite large and may include the other cluster. Data on both is too vague to even hazard a guess. Another galaxy I hoped to find something on is the blue smudge of a low surface brightness galaxy southeast of NGC 7779. NED shows it only as an Ultraviolet Source found by the GALEX UV satellite. Apparently, nothing else has even noticed it.

This field is near the Zone of Avoidance so poorly studied. I was surprised I found as much as I didn't. Normally I don't include names that are just coordinates, just listing them as G for galaxy, Q for quasar GC for galaxy cluster etc. This is because their labels get huge and often overlap. This field had no such issue and with little else, I broke my rule and included such identifications even when no redshift data was available. Don't expect to see this very often.

NGC 7778, NGC 7779 and NGC 7782 were discovered by William Herschel on November 12, 1784. NGC 7780 was discovered by Édouard Stephan on October 1881 and NGC 7781 was discovered by John Herschel on August 16, 1830.

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

Related Designations for NGC7778

NGC7798

NGC 7798 is a virtually unheard of galaxy in the eastern side of the Great Square of Pegasus. I found no images of it in Astrobin nor other forms. Why it is so ignored I don't know. My reason for taking it was two-fold. First, with all the dust I'm fighting I needed something bright that could cut through the smoke but not make nasty halos around the object or bright stars. Second, it is a galaxy that could have been put in Arp's catalog under galaxies with one heavy arm as the southern arm is much larger than the northern arm. Still, I couldn't find a decent amateur image of it. After lots of struggles, I think the color is about right. At least eXcalibrator is happy with it after lots of adjustments for the smoke. As a Markarian galaxy, it also attracted my interest as these sometimes can be quite interesting. This one turned out to be one of those.

One note at NED reads: "The UV image of this spiral galaxy (Fig. 7) presents strong emission associated with the nucleus, as well as several star-forming regions along the spiral arms. The H{alpha} emission traces what is seen in the UV, and also shows strong emission along the spiral arms, outside the region covered by the UV image. The radio shows only a strong nuclear point source, and some faint emission corresponding to the spiral arms." At nearly 100 million light-years it is too distant for my 6nm H alpha filter to see the H alpha light so I have to trust the pros about that. NED lists it as a SBc starburst galaxy. That could explain why it is surprisingly bright for its distance. Seligman however says it is Sc?. The bar isn't mentioned though I do see it in my image. I measure it at a diameter of 30,000 light-years. That isn't all that large for one as bright as it is.

The galaxy was discovered by William Herschel on September 18, 1784. It isn't in either of the H400 programs which I found surprising as it is reasonably bright. Bright enough to get through my smoke.

After this image was taken we had nothing but clouds but for one sucker hole. One night they cleared and I got two nearly smokeless objects. Then the clouds returned and I've been unable to do anything. Now the nearly full moon would be a problem but with clouds and rain, it doesn't matter. :(

Rick


http://www.mantrapskies.com/image-archive/NGC/NGC7798-MRK0332/NGC7798L4X10RGB2X10.JPG
http://www.mantrapskies.com/image-archive/NGC/NGC7798-MRK0332/NGC7798L4X10RGB2X10CROP125.JPG
http://www.mantrapskies.com/image-archive/NGC/NGC7798-MRK0332/NGC7798L4X10RGB2X10ID.JPG

Related Designations for NGC7798

NGC7800

NGC 7800 is an irregular Magellanic galaxy in Pegasus. Redshift puts it about 64 million light-years distant though a single Tully-Fisher measurement says 77 million light-years. One paper even +put it at 125 million light-years. I'11 call it 70 million as a nice round number that is pretty much in the middle of the two more reasonable estimates. It is a low surface brightness blue galaxy with strong UV emission. This is quite typical of an Im class galaxy. Being blue it has had recent strong star formation. There's an obvious galaxy seen through the western edge of the galaxy. It isn't listed in NED at all even though several thousand galaxies in my field are listed. So I marked it with a question mark. It shows in the POSS plates and other images so is real and not an artifact as I was beginning to suspect. It was discovered by William Herschel on December 24, 1783. It isn't in either H400 program.

Other than papers stating these obvious facts I found little on it so I'll move on to the field which is strangely absent of nearby galaxy but has several groups at 1.2, 1.9, 2.4 and 3 million light-years. These are marked in the annotated image along with a galaxy shown to be at the same position. WHL J235935.4+144135 is an oddity. While there's a very obvious large galaxy at its position the galaxy isn't listed in NED's database. So that galaxy cluster is just noted with the label GC rather than G/GC used for the others whose anchor galaxy was listed in the database.

Near the bottom edge of my image, a bit right of center is a galaxy at 2.0 billion light-years that shows some spiral detail. Doing the math shows, it to have a diameter of about 175 million light-years. That is one monster spiral galaxy!

There are several quasars in the image. The most distant has a z of 3.39 which means the light we see has been stretched in wavelength by a factor of 4.39 times due to how much our universe has expanded in the 11.8 billion years it took the light to reach us. Our galaxy may not have even existed when the light we see left it. In any case, the light had been traveling 7.3 billion years before our sun and the planets were even born. But if photons could think they'd have seen the trip as being instantaneous with no time between their leaving the quasar's accretion disk and slamming into my detector only to be turned into an electron ending its 11.8 billion year, yet instantaneous, life.

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

Related Designations for NGC7800

NGC7814

NGC 7814 is an edge on galaxy about 30 million light years away. There's a lot going on in this image so bear with me. First off this is an unusually transparent galaxy. In many ways, it resembles M104 which also is transparent. Note you see a "ghost" dark lane a bit to the left of the "real" one. Since the galaxy isn't perfectly edge on we can see the dust lane on the far side of the galaxy right through it as the ghostly second dust lane. The same is true of M104 but not at optical wavelengths. Also, you will see some fuzzy stars through the core bulge of the galaxy. Normally dust would make this impossible. Since the redshifts of these distant galaxies are very different from NGC 7814 it is easy to separate out what belongs to what galaxy allowing studies of how dust and gas in 7814 absorbs light from the distant galaxies and thus how much dust and gas 7814 contains. This turns out to be low for a spiral galaxy. It was discovered by William Herschel on Oct 8, 1784. It is in the second H400 program.

IC 5381 at the bottom of the image is classified as Sab?. Redshift puts its distance at 490 million light-years. Non-redshift measurements put it further away at about 560 million light-years. it was discovered by Isaac Roberts on a photographic plate in November 1895.


Also, note the smudge above the "north pole" of the galaxy. This is real but I can't find any mention of it anyplace and have no idea if it is a satellite of 7814 or something very different. If anyone knows let me know.

The obvious asteroid above the galaxy is (64856) 2001 YD42 at magnitude 16.2

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

Related Designations for NGC7814

NGC7822

NGC 7822 (see Sh2-171) is a star-forming region in Cepheus. It is also known as Ced 214. It is far larger than my field so I've just picked a part of it including the star cluster Berkeley 59 in the upper right corner and several "elephant trunks) near the bottom. APOD puts it at about 3000 light-years from us. Most images you see of this object are done using narrowband filters and the so-called Hubble palette (SHO) in which SII (sulfur) is mapped to red, H alpha (Hydrogen) is mapped to green and OIII (oxygen) is assigned blue. I've used pure LRGB. I've tried to balance the colors to show what the eye would see if it were equally sensitive to all colors. In fact, the eye is most sensitive to green so the nebula would appear somewhat green to the eye if it were bright enough to register on our cones that see color. It is too faint to do this even in very large scopes so appears just as a faint gray smudge with the stars of Berkeley 59 dominating. It was discovered by John Herschel on November 16, 1829.

The star cluster in the upper right corner is Berkeley 50. It is a young cluster only about 6 million years old so its very blue stars dominate. It is about 3,600 light-years distant according to WEBDA. That's about the distance to NGC 7822 considering how difficult it is to pin down the distances to these objects. Could it have formed from some of the gas in NGC 7822? I rather doubt it as WISE shows it to have its own nebula, only visible in IR light. https://www.nasa.gov/mission_pages/WISE/multimedia/wise20100316.html The NASA site puts both NGC 7822 and Berkeley 59 at 3300 light-years and considers them related.

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

Related Designations for NGC7822

NOVA VULPECULA2007

Nova Vulpecula 2007

Some nova are "Fast", some "Slow". Fast nova usually brighten quite a bit more than slow ones. How bright they appear to us is a function of distance so a slow nova can be brighter than a fast one because it is closer. Fast nova reach maximum brightness in a day or two while slow ones can take much longer. Nova Delphinus 1967 was discovered at 6th magnitude by George Alcock (a famous comet hunter recently deceased) in early July of 1967. But didn't reach a maximum of magnitude 3.5 until December then faded slightly only to reach another maximum in May of 1968. It was still brighter than magnitude 6 when it disappeared into the sun at the end of 1968 but was fading below naked eye level when it reappeared in February 1969. That was the slowest nova I know of. See my image of Nova Delphini No. 4 for a shot of it. It didn't have a red hydrogen shell as seen in this and the Nova Delphini No. 4 novas.

This one is a typical slow nova -- so far. It has faded only from magnitude 9.4 to 10.1 in nearly a month's time. I've not watched it closely due to the weather and not being here so don't know how smooth the light curve is. Usually, slow nova have a rough light curve with lots of ups and downs and often more than one "maximum". All fast nova I've observed have shown a vivid pink hydrogen cloud after only a few days from maximum. Slow nova, however, don't always show such a cloud. Nova Delphinus 1967 certainly didn't. But most do and this one is no exception. Below are two photos, dates shown on the photo. While the nova hasn't faded all that much it now shows that vivid pink HII color showing it did emit a lot of hydrogen gas in the explosion.

The exposure on the left used 5 one minute luminosity frames and 2 one minute ones for each color while the one on the right used 6 two minute frames and 3 two minute ones for color. The difference in exposure time makes it impossible to process them equally, I did the best I could in matching the two.

Related Designations for NOVA VULPECULA2007

NovaSagittarius2012No4

Nova Sagittarius No. 4 (how's that for a name) was just discovered. Since I thought I had a clear night I decided to give it a try. It is at 18h 20m 27s -27d 44' 27s so well below my limits. It is also below the walls of the observatory and in the trees along my shore, I can't trim as they are in the shoreline impact zone. So this was an interesting image compounded by the sky suddenly turning partly cloudy. At no time was more than the top 4" of my objective above the observatory wall. So while I was using a 14" scope I probably had only the equivalent of about 5" or so of true light gathering power. Then being so low and in the gunk, everything is severely extinguished. Color balance is also a WAG as the amount of wall obstruction got worse with time. I had to use 1 minute frames to catch what I could between tree branches and clouds. It didn't help that some fisherman was using a bright light to see his fishing buoy. It is illegal to use a light to attract fish except you can use a lighted marker buoy. Or, as this guy did, you circumvent the law by shining a 3 million candlepower light on your buoy so you can see it. That it attracts fish illegally, well, that's just a side effect. DNR folks can't cite him as he was just using a light to see his buoy which is allowed. That reflected into the observatory lighting up the wall thus fogging the image.

Due to severe atmospheric chromatic smearing caused by imaging so low I couldn't use any luminance data. It just resulted in prism smeared stars. So this is a pure RGB image. I debated using the red channel for the luminance as it was the cleanest due to fewer issues from tree branches and less extinction but it so distorted the brightness of some of the blue stars I gave that up and went with pure RGB.

I get a magnitude of 8.3 in red light but due to all the issues, I doubt it is all that accurate. Probably within a half magnitude at least, probably a bit better than that. Compared to known stars in the image, I was within 0.2 magnitudes most of the time. This was taken and is reproduced at 1.5" per pixel binned 3x3. Dimmest stars are about 16th magnitude, far from my usual limits!

I've included a POSS image from the 1960's showing no star visible at the location of the nova.

14" LX200R @ f/10 with severe wall obstruction. RG=6x1x3' B=5x1x3', STL-11000XM, Paramount ME

Related Designations for NovaSagittarius2012No4

P2010 A2

P/2010 A2 (LINEAR) is cataloged as a comet but it is no comet. It's the remains of two asteroids that smashed together. I've seen no estimate of when this happened. It was discovered in early January. I've been wanting to try and image it since then but until a couple nights ago I didn't have the skies to do it. This is a preliminary processing of the data. It is moving rather slowly but even that motion (about 0.0032" of arc per second) meant I had to have the mount track this motion to get much due to it being so faint. There's no way to guide on a cloud like this so no guiding was used. I had no way to align the 4 subs so this is just a stack as it came from the camera. I believe it is within 1" of the correct alignment but can't prove this. It's been enlarged from the native 1" per pixel to 0.5" per pixel to better show the detail. This is a crop of the entire image. The full image contained two asteroids only one of which made the cropped version. It is in the lower right corner. It is (50060) 2000 AA68 Since the scope was tracking the debris cloud the asteroid trail is distorted from reality. P/2010 A2 (LINEAR) was moving south-southwest while the other asteroid was moving west-northwest. Asteroids do fall into families with similar orbits. These two are unrelated.

Hubble imaged it about a week ago. Their image is a bit better than mine. You can read more about it at the link below.
http://hubblesite.org/news_release/news/2010-07

14" LX200R @ f/10, 4x10 minutes, STL-11000XM, Paramount ME. Taken binned 2x2 then enlarged 2x to 0.5" per pixel.

Related Designations for P2010 A2

P2016BA14

Due to high clouds and a nearly full moon lighting them up something awful I was unable to catch this piece of a comet at closest approach, about 2.2 million miles (3.5 million kilometers). The next night, March 23UT, 2016, cleared when the moon was full and closer to it and it was 2.5 million miles away (4 million kilometers). You have to go back to 1770 for a comet passing any closer. That one was discovered by Charles Messier himself and passed only 1.4 million miles (2.2 million km) from us.

Still, I was able to get 30 minutes worth of one minute images while the Paramount ME tracked the comet based on its orbital elements. Often I find the orbit of something passing close by is changed just enough the predicted path is a few seconds of arc different than it was when the orbital elements were calculated. But being a day late they had been updated and the tracking was so on target I didn't even have to align the 30 images used to make this mono image. Think that was a first and saved a step in processing them. Though the rising moon brightening the sky added a step to keep the background about the same for the movie version.

The comet was at about magnitude was 13.2, down from 12.9 the night before (prediction of the Minor Planet Center). When first detected it was cataloged as an asteroid but then a faint tail was seen causing it to be reassigned as a comet. It is thought to be a piece that broke off from Comet 252P LINEAR on a previous pass by the sun. That comet came by a day earlier at 3.3 million miles (5.2 million kilometers) but was only visible from the southern hemisphere at the time. It is much brighter at magnitude 5 (some say 4.5). It is still too low in Scorpio for me to catch. Maybe in a few days though by then it will be quite a bit more distant. Last I saw it had no sign of a tail, unlike P/2016 BA14, though it shows a nice large coma which seems absent for P/2016 BA14. All my image shows is a 13th magnitude asteroid-like object with a very faint southward pointing tail (looks like a dust tail to me). Radar imaging shows the little comet to be about 1 kilometer (3000 feet) across.

Besides the still image made from 30 one minute images of the comet, I made an animation of the first 15 of them. The images were made binning the camera by a factor of 3. Not because that increases the sensitivity (that's a myth) but because my camera is slow to download images. A full frame takes 27 seconds. That would have increased the time needed to make the image by 11 minutes. Still, the gaps in the star trails show how much the comet moved in those 5 seconds it took to download a frame. It was moving at about 38" of arc per minute. Since I was more than reaching a sky noise level that made the camera's read noise immaterial going longer than 1 minute wouldn't have helped the still image (and would have little effect on the animation) so I settled on 1 minute as a reasonable compromise. I'd likely have reduced an unbinned image to about this image scale to help hide the noise in the very faint tail structure anyway. Since I couldn't stack the frames for the animation the tail was lost in the noise level of a single frame. In fact, I saw no hint of it until I combined about 10 frames, it is very faint.

I hope I never have to image near a full moon again. What a pain it is.

14" LX200R @ f/10, L=30x10'x3, STL-11000XM, Paramount ME

Related Designations for P2016BA14