IC0431

IC 431 and IC 432 are two reflection nebulae just northwest of the far more famous Flame Nebula, NGC 2024 in Orion. While it might appear they are related the Hipparcos data for the central stars of each tells a different story. IC 431 to the west (right) has at its core the B3Vn star HD 37674 which Hipparcos puts at 1,059 light-years. Brighter and larger IC 432 to the east (left) has at its center B2IV HD 37776 aka V 901 Orionis which Hipparcos puts at 1,664 light-years. So not only does the nebula appear larger it really is even larger than the apparent difference in size would suggest.

Of possibly even more interest to astronomers is V 901 Orionis. It is a variable star whose rate has both increased and decreased over time with an overall decrease. Several papers have been written to explain its odd behavior. Both agree it likely is due, at least in part, to the magnetic braking of its rotation period as the star has a very strong magnetic field interacting with the interstellar medium. For those interested, see: http://cdsbib.u-strasbg.fr/cgi-bin/cdsbib?2008A%26A...485..585M and http://cdsbib.u-strasbg.fr/cgi-bin/cdsbib?2011A%26A...534L...5M for two somewhat different opinions.

The Flame Nebula is thought to be illuminated by the star Alnitak which Hipparcos puts at a distance of 817 light-years. While much of the red emission nebula seen in the image is due to the outskirts of the Flame Nebula its gas and dust are much closer than either of these nebulae. It's easy to think the three are related but apparently, that's not the case.

Also nearby and out of the image to the south is the top end of IC 434 which is partly obscured by the famous Horsehead Nebula. That is illuminated by Sigma Orionis which Hipparcos puts at 1,148 light years. Considering the difficulty of working at distances of over 1,000 light-years the error bar of the Hipparcos data is large enough I can't rule out that IC 431 and IC 434 might be related with a distance difference of a bit less than 10%. Hipparcos just wasn't that accurate at that distance. Though I'd have expected Sigma to have created some H alpha glow to IC 431 if it were really nearby so I'll say that while it is possible I doubt the two are related.

Both nebulae were discovered by Williamina Flemming on June 27, 1888.

Clouds nailed one of my usual 4 luminance frames and I didn't notice it until just now when I processed the image months after it was taken. Too late to go back and get more data. One green frame was badly hurt by clouds as well but it did help slightly to include it so I didn't throw it out like I had to the luminance frame. This made for a slightly noisier image than I'd have liked but fortunately, these are rather bright nebulae so I could make it work at the cost of some of the finer detail. The seeing was poor so likely wouldn't have allowed that detail even with the lost frame.

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

Related Designations for IC0431

IC0446

IC 466 also known as IC 2167 and CED 77 is part of a large molecular cloud in Monoceros west of the more famous NGC 2264 home of the Cone and Fox Fur Nebulae. The cloud is thought to be about 2500 light-years from us. It includes the far larger IC 447/2169 (another IC entry that has two numbers) and NGC 2245 and NGC 2247. While I've taken IC 447 my field is too small to mosaic the two without a third frame between the two. I'm yet to work on the two NGC objects which will fit one field. They were on the list for 2013 but the weather had other ideas so it never happened. Also in the image is the dark nebula LDN 1607 and vdB 79 and a lot of Young Stellar Objects marked in the annotated image. Both IC numbers are due to its discovery by Edward Barnard. First on January 24, 1894 then sometime after 1895. The first entry is responsible for the IC 446 entry.

While it might appear the bright star in the center is the illuminating star The Sky puts its distance at a mere 66 light-years so it lies well in front of the nebula. SIMBAD identifies the illuminating star as VY Monoceros. This is the very orange star at the edge of the dark nebula below the main part of the nebula. A red star illuminating a reflection nebula? Nope -- it's not red! It is a 09 star, so blue much of its light is in the ultraviolet part of the spectrum. It is apparently red only because it is severely buried in the dust of the dark nebula it is nearly hidden behind. Appearances can be very deceiving it seems. This dark cloud likely hides much of the reflection nebula as well.

I caught two asteroids, (111762) 2002 CL131 at an estimated magnitude of 19.2 to the southwest of the nebula just above the dark nebula and the far more interesting (to me at least) asteroid I call Frankenstein's grandmother's asteroid. It's at the top center of the image. It carries the official name of (90481) Wollstonecraft and is at an estimated magnitude of 18.2 according to the minor planet center. So why do I call it Frankenstein's grandmother's asteroid? Those up on English literature likely know. For those that don't here's the connection which I found quite interesting.

I'll start with its naming citation:
"(90481) Wollstonecraft = 2004 DA
Mary Wollstonecraft (1759-1797) was a revolutionary champion of gender equality. Arguing that the rights of women, as those of men, rely on intellectual, economic and legal autonomy, she challenged the mores of her time and influenced feminist thought for centuries." That's quite an understatement if you look up her biography.

Does that help? If not I'll continue. Mary Wollstonecraft died at age 38, 10 days after giving birth to her only legitimate daughter, Mary Godwin. You likely know Mary Godwin by her married name, Mary Godwin Shelley -- the author (mother) of Frankenstein!

See what you can learn when you research your images! You may get an unexpected lesson in English literature.

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

Related Designations for IC0446

IC0447

IC 447 is a reflection nebula in Monoceros. Its distance is rather vague but I'll say about 2,500 to 2,700 light-years. It was discovered by Edward Barnard -- twice. Once on January 24, 1894 and again sometime in the late 1890's and entered as IC 2169. The first discovery earned the IC 447 listing. It is sometimes known as Dreyer's Nebula, why I don't know.

This one was taken when I had a severe light leak in the camera that created a nasty gradient and blew out red features causing red arcs around many of the stars. At the time I didn't have the tools to deal with this. To help reduce the issues this caused I'm reproducing this one at 1.5" per pixel rather than my normal 1" per pixel. I need to retake this one but don't hold your breath.

14" LX200R @ f/10, L=6x10'x2, RGB=2x10'x3, STL-11000XM, Paramount ME

Related Designations for IC0447

IC0466

IC 466/Sh2-288 is a small emission nebula in central Monoceros. I found three different distance estimates. Two say 3000 parsecs (about 10,000 light-years) and one says 4100 parsecs (13,000 light-years) give or take 6500 light-years which more than overlaps the two other estimates. Several sources say it is illuminated by an O9V star but not its designation or coordinates. Is it the blue star to the northeast, is it the star that appears to be in the center of the nebula or is it some other star? I couldn't find an answer to that.

If the 10,000 light-year distance is assumed it is about 6.5 light-years across. Rather small for most emission nebula. Besides the two designations above it is also known as LBN 1013 and Min 2-63.

The nebula was discovered by Stephane Javelle on February 18, 1893. He described it as an "11.5 magnitude star in a very faint nebula." He often used the 30" refractor at Nice Observatory in finding some 1300 IC objects. If this description was made with that scope it must be a difficult visual object.

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

Related Designations for IC0466

IC0467

When I imaged NGC 2336 in 2013 I noted some references said it was a non-interacting pair with IC 467. That caused me to put that galaxy on the to-do list. It was finally taken last March. Since my field is 20 minutes high and NGC 2336 is 20 minutes, mostly north of IC 467 I couldn't fit them into the same field. Even rotating the camera wouldn't do it due to the large angular size of NGC 2336. Both of these are located in Camelopardalis only 10 degrees from the north celestial pole. NED shows a redshift distance for IC 467 of about 95 million light-years with non-redshift measurements at 105 million light-years. They classify it as SAB(s)c:. Seligman agrees but leaves of the questioning colon. The galaxy was discovered by William Denning, an English astronomer, on November 7, 1890. It was one of 17 new IC objects he found using a 10" reflector.

Since it has been considered a companion of NGC 2336, even though the images were taken over 2 years apart I did manage to mosaic the two together without reprocessing the NGC 2336 image. Though it was taken under better seeing the two merged without any adjustment to either. Though that makes the seam obvious if you look for it. I'm just too tied up for time to reprocess to match. Apparently, I processed them very much alike. Not sure what that says about my improvement in processing over the last two years. Redshift data puts NGC 2336 at about 100 light-years with its non-redshift measurements at 105 million light-years. Thus it is quite likely the two are a gravitationally bound pair. There may be other dwarf companions but with no redshift data for any other galaxy in the field, I can't identify any candidates. NGC 2336 was discovered by Wilhelm Temple in 1876. I couldn't find any better date. It is classified SBbc by Seligman and SAB(r)bc;RET Sy2 by NED. I covered what a retired nucleus was in an earlier posting but it is basically one in which starburst activity has ceased as has nearly all star-forming activity near the core. Though the black hole seems to be still feeding rather well since it is a Seyfert 2 galaxy. My post from October 4, 2013 is at: ( http://www.cloudynights.com/topic/436033-ngc-2336-a-rarely-imaged-beautiful-spiral/ or http://www.spacebanter.com/showthread.php?t=199390 )

With no other galaxies having any data at NED I didn't prepare an annotated image.

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

Related Designations for IC0467

IC0480

I put IC 480/2MFGC 6287 on my to-do list when I saw an amateur image of it that showed it as very blue. An edge on galaxy may be blue at the ansae but usually is quite reddened for much of its length so this was highly unusual. Looking at the POSS images I thought I saw the same. But after processing, I find it is quite typical of flat edge on galaxies so wasn't blue after all. Still, it is a flat galaxy though not flat enough to make it into the Flat Galaxy Catalog but is in the 2 micron version which is a bit more lax on entrance requirements. Also, its dust lane is not straight as is typically seen and there are several bright blobs seen against the edge on galaxy. Several are listed at NED as being separate galaxies though I'm quite sure they are just star clouds in the galaxy as their redshift is very similar to IC 480. Though seeing such clouds is rare in edge on galaxies. It is classified by NED as Sbc and Sbc? by Seligman. It was discovered by Stephane Javelle on March 18, 1892. It is a rather large spiral at about 125,000 light-years in diameter assuming the redshift distance of 220 million light-years.

The field turns out to be rather interesting. It is located in northeastern Gemini not far, 2.5 degrees, from Pollux. To its southwest is the radio galaxy AGC 172071 also at a redshift of 220 million light-years. It appears to be a strange dwarf galaxy. NED's only catalog entry for it is from a radio catalog. None of the visual catalogs seem to have an entry for it.

To the northeast of IC 480 is another highly strange looking galaxy, PGC 22209 at 450 million light-years. It appears rather disrupted having various parts, dim and rather bright. Tucked in between two bright regions is what NED classifies as another galaxy, ASK 180095.0. It is shown to be 500 million light-years distant. A bit too much difference to be just part of the galaxy so likely is a separate galaxy behind it. It is a tiny spherical object. Nearby to the east PGC 022221 is a two armed spiral in which the southern arm is much broader and brighter than the northern one. It is some 830 million light-years distant. It is listed as an SC galaxy by NED. To its east is the S0 galaxy PGC 022227 which has what appears to be a rather obvious dust lane on its eastern side.

To the southeast of IC 480 is small (in appearance) edge on ASK 204215.0. If brighter it likely would make one or both of the flat galaxy catalogs but is too faint for either. It is small only because of its distance of 1.17 billion light-years. It is actually larger than IC 480 at 150,000 light-years in size.

The field contains several quasars (Q) and quasar candidates (QC). The candidates have only a photometric redshift which can sometimes be incorrect. NED lists dozens in the field. I've identified only those NED seems to feel are likely valid but still calls them candidates until more data is in.

Two asteroids were caught in the lower part of the image. See the annotated image for details.

Transparency was a bit better than I've had, still below what used to be normal, which allowed me to pick up some galaxies out as far as 4 and 5 billion light-years. They are marked in the annotated image.

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

Related Designations for IC0480

IC0498

IC 0498 is a spiral galaxy that fits Arp's category for spirals with one heavy arm. Its arm seems odd in that the heavy part spirals in to the end of a much finer arm that spiral in to the eastern side of the core. A similar arm comes off the western side and ends in what appears to be a bunch of star clusters or is it debris from something the galaxy is digesting? NED lists one of these, up by where the heavy arm meets the much finer arm coming from the eastern side of the core, as a separate galaxy but with the same redshift. Even on the Sloan image, I can't see it as anything different than many other such star clouds in the area. The galaxy is in southeastern Canis Minor about 470 million light-years distant.

The UGC says of it: "Strongly deformed spiral pattern, bright arc in northwest, eccentric nuclear region, no disturbing object visible." The bright arc being the heavy arm in Arp's terminology. While there is no "disturbing object" in the area the galaxy is part of ZwCl 0806.8+0514, a cluster of 220 galaxies in a medium compact cluster some 73 minutes of arc across according to NED. The cluster is centered about 5 minutes south of my image's southern edge. That means my image is well within its boundaries covering only part of its northern region. With that many galaxies, it wouldn't surprise me if one wasn't the cause of IC 498's apparent indigestion from eating it.

IC 498 was discovered by Rudolf Spitaler on November 11, 1888 apparently using the 27" refractor at Wein University in Vienna on November 11, 1888. He found 64 IC objects while at the university, most of them from 1891 to 1892. Though 54 are galaxies, one, IC 1470, is an emission nebula. The rest are dubious at best. One is a single star, four double stars, two triple stars, yet another a quadruple star and the last can't be identified with anything in the sky. Seems he was a bit over anxious to find objects. In fact, it was a race between astronomers of that era to find these objects. IC 1440, his only emission nebula, was discovered by Barnard only one day later. In the pressure to find one before someone else, it seems on nights of less than ideal seeing stars became deep sky objects, especially when in tight groups of two to four. A single star at the magnitude limit for the night can also create the illusion of an extended object. Even today's photographic searches make mistakes, just not as obvious as those of the days of visual astronomy.

Speaking of conditions they were awful for this one. I tried on three different nights, all of which were of 3.5" seeing or worse. While the third night was better for seeing transparency was awful. I ended up including 9 of the luminance images taken as including just the 4 from the best seeing night didn't go very deep at all. By including even those down to 4" seeing I managed to get my usual depth but at the cost of resolution. I used the three best of 6 color frames taken those nights for each color. I threw out those of such poor quality they added only noise to the final result when included.

14" LX200R @ f/10, L=9x10' RGB=3x10', STL-11000XM, Paramount ME

Related Designations for IC0498

IC0527

My original object of interest was IC 527 due to an entry in the UGC stating "Smooth faint disk, no spiral pattern." Yet the POSS image showed a very obvious spiral pattern and hints of fainter outer arms disconnected from the disk. When I took my framing image interesting galaxies were near the western edge so I move the field west to pick them up. Started the imaging run and went to bed. I went to process it weeks later and found I was in trouble. One totally useless, one weak and the two "good" ones were weaker than normal. Conditions had to have gone south soon after I started. Yet the color frames were all good. Since I didn't see this until too late to retake it I decided to make a pseudo color image from the three sort of usable L frames and all the RGB frames. Thus it loses a good magnitude or more and is noisy but at least I had something to work with. It's back on the to-do list for next year as it is full of interacting galaxies. The field is located in southeastern Lynx. Edit: Somehow I've never gotten back to this field. Also, this illustrates why I don't bin color as most imagers do. I'd have lost not only depth but also resolution had I binned the color data when using it to salvage poor luminance data. Contrary to popular opinion I don't find I need more time for color data because of this.

It turns out IC 527 may be one of the less interesting galaxies in the field. But for its strange arm structure, it is otherwise rather normal looking. NED says it is S? with no mention of a very obvious bar. Seligman does see it and classifies it as SBc?. It was discovered by Lewis Swift on April 19, 1890. IC 527 it is about 320 to 330 million light-years distant by redshift.

To the northwest is PGC 025786, a highly disturbed Sb spiral with one arm pulled out to the south and a faint plume to the southeast.

Well to the west is normal NGC 2759 classed as S0-: by NED and E/S0 by Seligman. It has a redshift that puts it slightly further away than the other two but I suspect this is more due to its velocity in the group rather than a real distance difference. It was discovered by William Herschel on March 30, 1787. It isn't in either Herschel 400 observing program.

Heading south from NGC 2759 we come to PGC 025734 listed by NED as SB(s)b pec. It certainly is peculiar all right. It has a long straight plume to the southwest that suddenly broadens out and curves back toward the galaxy before fading away along the east side of the galaxy. This curving part carries its own galaxy designation at NED. See the annotated image for details. This galaxy is also 320 million light-years distant. Is it messed up because it interacted with PGC 025786? The plume seems to point back to this galaxy and it too is disturbed.

Quite a few other galaxies in the image are also about 320 million light-years distant indicating this is a rather large group but I never found any galaxy cluster or group that included them all. I didn't check outside the bounds of the image, however.

Going back east from PGC 025734 brings us to the double galaxy PGC 025760. These two are obviously interacting with large plumes coming from the eastern galaxy. Only the western member, ASK 206485.0 has a redshift measurement at NED. That puts it some 1.35 billion light-years distant. How I wish this pair was much closer. It likely would be a spectacular crash scene.

Go south and a bit west from PGC 025760 and an even more distant pair is seen. Only the eastern member has any redshift data. NED puts it, ASK 267925.0, at some 2.15 billion light-years. I assume the two are interacting since they appear to be sharing a common halo of stars. Unfortunately, due to conditions, this is hard to see. I checked the Sloan image with confirms the shared halo.

In the upper right corner is the flat galaxy FGC 841 which NED lists as an Sc spiral with a possible DANS core. What is that you ask? I had to look it up. It stands for Dwarf Amorphous Nuclear Starburst--Introduced by Salzer et al. ([1989]), they show very similar spectroscopic properties to SBN objects, but with alpha luminosities lower than StarBurst Nuclear galaxies.

Three quasars are shown in the annotated image. All are shown as candidate quasars in one place but under the general heading of actual quasars. All have large spectroscopic redshifts indicating great distance. Since it is quite likely they really are quasars that's how I've labeled them in the annotated image.

14" LX200R @ f/10, L=3x10+RGB2x10', RGB=2x10' (they get double duty), STL-11000XM, Paramount ME

Related Designations for IC0527

IC0528 HCG36

IC 0528 is the main galaxy in the HCG 36 4 galaxy group. Hickson chose his compact clusters by their appearance on the Palomar Observatory Sky Servey images. They had to meet his criteria for being compact, having at least 4 galaxies whose brightness had to fall within a rather tight range. Note they didn't have to be a true group by distance. Only that they appeared compact from our line of sight. This is a good example with 2 of the four having a distance of about 710 million light-years, another 400 million and the most obvious, IC 0528 is only 190 million light-years distant by redshift. A fifth galaxy looks like it should have made the group but was too faint to make the cut. Oddly it is about the same distance of IC 0528 so by distance there are 2 galaxies at about 710 million light-years, two at about 190 to 180 and one in between at 400 million light-years. Still, as seen from our location in space they appear close together though by size it would appear 4 are about the same distance with IC 0528 being much closer. Actually, by redshift, the smallest is the closest.

What I find interesting about IC 0528 and why it went on my to-do list is the outer ring appears to be in a different plane, tilted with respect to the inner part of the galaxy. Is this real or an illusion? If the latter it is a darned good illusion. I found nothing in the literature on this.

The group is located in western Cancer a half degree from the ecliptic. This explains why there are 5 asteroids in the image. While they aren't confined to the ecliptic like the planets they do all cross it and the majority never stray more than about 15 degrees from it. So when imaging near the ecliptic, expect to pick up asteroids.

The field is full of distant galaxies. I've shown the redshift distance to all which NED showed a redshift value. They are very tiny, star-like, faint objects. You may need to enlarge the image to see those down in the 23rd magnitude range. But there are two that don't fit. On the far right about the middle of the frame is a near 23rd magnitude galaxy only 59 million light-years distant rather than 4 to 6 billion light-years the others are. It is a really tiny dwarf galaxy. I measure its size at 1,200 light-years. Now that's a dwarf galaxy! Or the redshift is very wrong. The other misfit is in the upper left corner. There you find what I'd have said was a nearby, blue, dwarf galaxy. Problem is NED puts it at nearly 7 billion light-years distant. Farther out than any other galaxy in the image, all of which are near star-like points. At a z of 0.813, it would be severely reddened yet is blue. Stars blue enough to survive such a redshift would be very short lived. To have an entire galaxy that way seemed beyond belief to me. Also, its size would be over 600,000 light-years in size. Something appeared very wrong. Then I noticed an "essential note" at NED. These are usually of no interest. They sometimes carry a different redshift than NED reports but doesn't think correct. It gives a distance of only 400 million light-years. That gives a size of 35 million light-years. Now everything makes sense. Why NED chose the obviously questionable redshift over the apparently correct one I don't know. It sure had me going for a while.

There are a few galaxies I'd like to know a bit more about. I labeled one edge on, the apparently flat galaxy at the top, toward the left edge but couldn't give it a distance estimate. You'll see others but like the one I labeled, they only have positional names and not much more at NED so I didn't label them. The image was getting rather cluttered as it is.

The naming citation for the one named asteroid reads:
(37044) Papymarcel = 2000 UE29
Marcel Alphonse Merlin (b. 1922) is the father of the discoverer. Now celebrating his eightieth birthday, he was the principal artisan in the construction of the discoverer's private observatory.

IC 0528 was discovered by Stephane Javelle on December 16, 1893.

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

Related Designations for IC0528 HCG36

IC0529

IC 529 is a nice spiral galaxy in Camelopardalis that might fit Arp's category of spiral galaxies with three arms. It is about 110 million light-years distant both by redshift and the median value of 17 other distance measurements, mostly Tully-Fisher. That gives it a size of about 125,000 light-years, a good size spiral. It was discovered by William Denning, an English astronomer in 1890 using a 10 inch Newtonian reflector, much like many amateurs of today use. He found 18 IC objects, 15 galaxies, two open clusters and one planetary nebula between 1890 and 1892.

Arp considered three armed spirals to deserve their own category but then only put three in it. The third arm in all appears more like an arm segment as does the third arm here though in this case, the segment is longer and brighter than either arm coming out of the core.

The field contains the rather nearby Abell 765 galaxy cluster. NED lists it as being 30 minutes across which is larger than my field though it appears all members are in the left half of the image. The label for it is centered on the position NED gives for the cluster. It is listed as richness class 2 which is Abell lingo for clusters with 80 to 129 galaxies. NED classes it as Morphology class III (BM). This is using the Bautz-Morgan classification scheme in which III is midway between a cluster dominated by a huge cD elliptical galaxy and one with large spiral galaxies and having no "remarkable" members. NED puts the cluster at nearly 1.7 billion light-years though all the members NED has a redshift distance for are listed as being a bit more distant, more like 1.8 billion light-years. The few galaxies NED had redshift measurements on all appear to be members of the cluster but for IC 529 making it a rather lonely galaxy, at least at my image scale. This far, north 73° 45.5', redshift data is usually rather hard to come by. Thus there are a lot of galaxies not included in the annotated image as they often weren't even in NED, at least as galaxies and if they were had no useful data.

Seeing was highly variable creating major issues when it came to color data. Red was taken last while conditions were deteriorating since it is supposed to be least bothered. But during the exposure seeing created some nasty distortions the likes of which I've never seen. It set off an alarm waking me so I came out and watched the red get clobbered. I tried to process as much of the red flares out as possible but some still remain. Fortunately, the luminance was taken under somewhat better conditions but oddly some stars were randomly elongated. The temperature dropped from -18C to -33C while this was taken. I assume that sudden drop had a lot to do with these issues. RegiStar worked overtime trying to correct the image scale of every frame. I picked one in the middle of the temperature drop as the reference. I don't know if that was the best choice or not. I've never dealt with such a drop in only 2 hours before. As I was running the camera at -35C it finished at 1% cooling power! Often that dropped to 0% but the darks worked well so I got away with it.

14" LX200R @ f/10, L=4x10' RGB=2x10' (blue the best 2 of 4), STL-11000XM, Paramount ME

Related Designations for IC0529