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

NGC7788

NGC 7788 and 7790 right to left. These two small open clusters are located in Cassiopeia and are about 7,700 and 9,600 light-years away respectively. The distance to NGC 7790 is likely more accurate as it contains three Cepheid variable stars which help pin down its 9,600 light-year distance. NGC 7788 is a rather new cluster, probably only about 40 million years old. NGC 7790 is thought to be a bit older at 56 million years old. I've seen speculation the two clusters are related since the distance to NGC 7788 is rather uncertain. But the age difference would seem to rule this out.

The three Cepheids in NGC 7790 are rather easy to find. They are the TWO brightest orange stars at the Northwest end of the cluster. Notice the brighter of the two is a bit elongated. Seems it is a binary made up of two Cepheids and is known as the variable CE CAS the other Cepheid to its southeast is CF Cass. The bright blue star below the southeast end is the eclipsing binary QX CAS and was discovered in 1956 when the Cepheids were being studied. It varies from 10.19 to 10.7 magnitude.

NGC 7788 was discovered by John Herschel on October 5, 1829. NGC 7790 was discovered by William Herschel on December 16, 1788. It is in the original H400 program. My log dated July 11, 1985 on a good night with my 10" f/5 at up to 140x reads: "Small oval (not circular) cluster of mostly faint stars against a background of unresolved stars. No condensation seen. NGC 7788 is visible to the north even at this power. It is smaller and less impressive."

My system isn't well suited for most open clusters. These two fit my system rather well. I haven't stretched the image nearly as far as I usually do for faint galaxies so it doesn't begin to go as deep as I normally go. This seemed to make for an image that didn't look as flat as my clusters do with more stretching as it packs too much range into the limited range of a computer monitor. I thought this one came out better than most of my attempts at open clusters. Since there wasn't much to see at higher resolution I down converted the image to 1.5" per pixel from my normal 1" per pixel.

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

Related Designations for NGC7788

NGC7789

NGC 7789 is an open cluster in Cassiopeia. It is one of my favorite visual star clusters in my 10" f/5 scope. It is thought to be about 8000 light years distant and about 1.6 billion years old. Its most massive stars have turned to red giants that seem clustered on the western edge of the cluster. The blue A and F stars are still on the main sequence and give rise to the blue color stars that dominate the rest of the cluster. The cluster was discovered by Caroline Herschel on November 1, 1783. It is about 16 minutes of arc across which translates to about 37 light years in diameter at 8000 light years. If there are any inhabitants of a star in the cluster they would have a rather bright starry sky to wonder about with a sky full of Sirius like stars shining down on them along with a few far brighter red giants.

Dreyer's description reads: "Cluster, very large, very rich, very much condensed, stars of 11th to 18th magnitude." I'm not sure I agree with the "very much condensed" however. Sure seems rather even in my image and that agrees with my visual impression in the 10".

14" LX200R @ f/10, L=10x5' RGB=2x10'x3, STL-11000XM, Paramount ME

Related Designations for NGC7789

NGC7790

There is a line of open clusters in Cassiopeia that's far longer than my field of view allows. Here I've picked up the two furthest east, NGC 7790 and Berkeley 58 (upper right to lower left). All may be closely related. I imaged NGC 7790 and NGC 7788 back in 2011. The others further north and west are still to be taken. Those are Frolov 1, Harvard 21 and King 12. Only King 12 is really recognizable as a cluster from the rich Milky Way background.

This rich background makes it hard to tell where a cluster ends. For this reason, I found sizes ranging from 4.5 to 7.5 minutes for NGC 7790 and 5 to 8 minutes for Berkeley 58. In fact, I found little agreement on much of anything to do with these clusters.

NGC 7790 was listed as being 9,600 light-years distant, reddened by .53 magnitudes and having an age of 56 million years by WEBDA. Another paper (http://arxiv.org/abs/1211.6398) says it is 10,300 +/- 500 light-years distant and 50 to 100 million years old. Wikipedia says 10,800 light years distant with an age of 60 to 80 million years. Other values can be found as well. Combine this with the various size estimates and the cluster is 13 to 22 light-years across. It contains 3 well studied Cepheid variable stars and even with that there's little agreement on this cluster.

NGC 7790 was discovered by William Herschel on December 16, 1788. It is in the original H400 program. My log dated July 11, 1985 on a good night with my 10" f/5 at up to 140x reads: "Small oval (not circular) cluster of mostly faint stars against a background of unresolved stars. No condensation seen. NGC 7788 is visible to the north even at this power. It is smaller and less impressive." Berkeley 58 wasn't plotted my atlas, that may be why I didn't see it or it could have been out of the field as it is further from NGC 7790 than NGC 7788 is.

Things are no better with Berkeley 58. WEBDA says it is 12,000 light years distant, reddened by 0.55 magnitudes and 250 million years old. But another paper (http://mnras.oxfordjournals.org/content/388/1/444.full.pdf) says it is 10,000 light-years away, reddened by .7 magnitudes and 100 million years old. I found size values of 5 to 8 minutes of arc giving a size range of 14 to 28 light-years depending on which size and distance you use. It contains a single well studied Cepheid which doesn't appear to help any more than the three in NGC 7790 to pin things down.

Also in the image is a ghost of a flat galaxy, 2MFGC 18005. It is faintly visible as a somewhat red fuzzy streak west of Berkeley 58 and below NGC 7790. I wouldn't have prepared an annotated image but this galaxy is so difficult to spot I made one just for it. When I saw it on my FITs stack I thought it an asteroid but then it was very faintly seen full size on the individual frames showing it wasn't an asteroid (one this high in declination is rare). While it appears flat enough to qualify for the flat galaxy catalog it isn't listed there for some reason. This is such an obstructed region they may not have searched this area for flat galaxies. NED lists no other galaxy in this area but for what appears to be a duplicate entry for this one with a slightly different position with a 35 second of arc error circle that easily includes 2MFGC 18005. The galaxy hosted a supernova back in 2007 which is how I came to learn of it. I wanted to catch it but that never happened. I can't recall why.

Weather limited my color data for this cluster. I can't say the color data is as good as I'd have liked. Only the red frames were sort of clean. Both blue frames were weak and hazy. Only one green frame was usable and it was dimmed by clouds. I never had a night to retake the data, besides this was my third try with the other two a total loss due to weather.

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

Related Designations for NGC7790

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