IC0405

IC 405 is the famous Flame Nebula. It is a nebula lit by AE Aurigae, a 6th magnitude O9.5V Orion type variable star. Such stars erupt at irregular intervals and are often found associated with nebulae such as in this case. Though this one is brighter and more extensive than most. Such stars are usually very young and still finding their hydrogen fusing stage of life. AE Aurigae is the bright star in the image and varies between magnitude 5.78 and 6.08. O9.5V stars emit most of their light in the ultraviolet range. This excites the hydrogen and other gasses it has emitted to glow, mostly red for hydrogen and cyan for OIII emissions. But being so bright they can illuminate the dust and gas as well. Being very blue and because the dust and gas molecules are very small the reflection nebula this creates is blue. Most take this nebula in narrowband picking up the emission lines but missing the reflection portion. I didn't use narrowband for this image as the hydrogen emission is quite strong in the area I took so I didn't need narrow band filters for the fainter parts outside my frame.

The nebula is said to be about 1500 light-years distant which fits the Hipparcos data for AE Aurigae which is 1456 light-years. That would make my field of view about 14.7 light-years across at the 1500 light-year distance. The nebula was discovered by John Schaeberle on March 21, 1892. Apparently, the glare of AE aurigae helped hide it from view. He found it on a photographic plate taken with the 6" Crocker-Telescope at Lick Observatory. It is the only IC object he ever discovered. Since I'd not heard of this instrument here's a link to a picture of it http://www.klima-luft.de/steinicke/ngcic/persons/pic_obs/lick_crocker.jpg

This was one of my first images after moving to color. The data goes back to the fall of 2006. At the time I didn't realize using 5 minute sub exposures created a lot of read noise issues drowning out faint features unless I took a lot of them, so I did just that. Today, using longer subs it wouldn't need the 125 minutes I gave it for luminance data. Still, it came out so well after reprocessing, I've not felt a need to retake it.

There is one asteroid in the image, it is (13918) 1984 QB at magnitude 16.9. It appears faint because at the time I didn't realize that stacking 25 frames would mean it appears in only one of 25 frames so averaging them would mean their brightness would be dimmed greatly. I now do it differently to preserve their brightness. While I reprocessed this image I used the original stack.

14" LX200R @ f/10, L=25x5', RGB=3x5', STL-11000XM, Paramount ME

Related Designations for IC0405

IC0410

Emission nebula IC 410 with two "Tadpoles" and the open star cluster NGC 1893. The nebula as a huge star factory. It is lit by these stars which are the star cluster NGC 1893. Likely part of it is hidden behind the dark "hole" of dense dust and gas just right of the cluster we do see. The tadpoles were (million years ago) Bok Globules like I've shown in previous images. But the light pressure from these stars has eroded the globules pushing their material "downwind" of their solar wind. Note how the two tadpoles seem to face right toward the center of the dark "hole" where these stars are located. Other currents from stars that formed to the side of the main cluster have created other winds that have distorted and kinked the tadpole's tails.

This complex is located in Auriga about 1.5 degrees south and a bit east of IC 405. My The Sky Pro's database equates IC 410 with NGC 1893 calling them both a star cluster and giving exactly the same coordinates for both but does not cross-reference them, treating them as totally different objects. In fact, NGC 1893 was discovered by John Herschel on January 22, 1827. He made no reference to a nebula and it is quite doubtful he could have seen it. The nebula IC 410 was discovered by Max Wolf on September 25, 1892. While it is clear he saw the nebula it appears it likely only saw the brightest parts of it as again, his scope likely didn't have the ability to see anything but the brighter parts. So it is certain they are different objects even if The Sky Pro is confused on the issue.

The distance to this object is hard for me to pin down. I've seen values from 9,000 to 19,000 light-years. Many say it is part of the same star forming region that included IC 405. But most put its distance at only 1,500 light-years. So that can't be right even though they are apparently close in the sky. APOD puts it at 10,000 light-years along with nearby IC 417. I'll go with that until something better is available. At least they didn't equate its distance to that of NGC 405 as Sky and Telescope and other sites have.

This is a very old image of mine taken before I'd moved to taking color. It is a pure H alpha narrowband image of the nebula so does dim the stars considerably. Though my processing of stars back then was awful and my tools severely limited. I only had 8-bit tools back then for example. I should redo it with good tools but that will likely wait until I collect color data and luminance info to pick up any reflection nebula component, if any. I normally only see narrow band images so don't really know if has any or not. Likely not nearly as much as nearby IC 405 has.

14" LX200R @ f/10, Ha=3x30', STL-11000XM, Paramount ME

Related Designations for IC0410

IC0417

IC 417 is a nebula in Auriga that I'm going to say is about 10,000 light-years distant. It was discovered by Max Wolf on September 25, 1892 and included in his paper on extended nebula he'd discovered. Though, in any scope of his size, it is the open star cluster that is easiest to see. So while the IC 417 designation applies to both the nebula and cluster it is really just the nebula Wolf was including in his find. The cluster does carry the separate designation of Stock 8.

The stars of the star cluster are eroding the nebula with their intense light. Notice the dark regions are surrounded by bright blue structures showing they are under attack from the intense ultraviolet light of these stars. While stars are trying to form inside these dark clouds it is a race to see if they can form before the cloud is torn apart by the radiation of already formed stars.

The common name for this nebula is the Spider Nebula. It has a nearby companion nebula (out of my frame) that is called The Fly, NGC 1931). The red filament going off to the left side of the image points right to it as if it just broke off from a spider silk and is getting away. An APOD image of both can be seen here https://apod.nasa.gov/apod/ap100113.html

The brilliant K4III star composed of 2 5th magnitude stars sent a nasty halo across much of the image making much of the LRGB data difficult to use. My newer filters that have much less of a halo issue would likely allow me to get a better image but that hasn't happened so I'll go with this image after many hours of struggle to clean up the damage.

14" LX200R, L=4x10' Ha=3x30' RGB=2x10x3, STL-11000XM, Paramount ME

Related Designations for IC0417

IC0421

IC 421 and VV 848 are a pair of interesting but unrelated galaxies either of which could have easily made Arp's atlas of peculiar galaxies. The field is located where you'd not expect such interesting galaxies to reside, Orion 2.6 degrees south of the far more famous Orion Nebula.

IC 421 would qualify for Arp's category of galaxies with one heavy arm. Besides the long drawn out and rather bright arm to the north the galaxy's structure is very lopsided with the core well east of the center of the galaxy's disk. It is classed as SAB(rs)bc and is about 165 million light-years distant by redshift though a few Tully Fisher measurements put it some 20 million light-years closer. It is a rather low surface brightness galaxy but for that one arm. Including its faintest outer parts, it is nearly 200,000 light-years across. It was discovered by Williamina Flemming on June 27, 1888. The story of how a woman astronomer at Harvard managed such a feat is rather interesting. At the time women were reduced to menial tasks though often demanding good math skills as they were human calculators in many cases. Williamina was a Scottish woman abandoned by her husband and working as a maid for Edward Pickering who according to legend was so upset with his male assistants proclaimed his maid could do a better job -- and she did. She didn't find objects looking through the telescope but by examining photographic survey plates. Most of her work was for star identification and classification. She is credited with 43 IC objects however with not the most famous of her finds. She was the first to notice IC 434 describing a dark patch in it now known as the Horsehead Nebula. The image was taken by William Pickering, brother to the far more famous Edward Pickering. Dreyer gave credit for all of Harvard discoveries in the first IC addition to Pickering but didn't specify which Pickering. Most assume he meant William. Later discoveries in the second addition were credited properly.

VV 848, at a redshift distance of nearly 400 million light-years and classed as S0+ pec: by NED, would qualify for Arp's atlas under any of several possible categories. Material ejected from the nucleus or diffuse counter-tails or just diffuse elements would all seem to fit as he has something similar in all of these. In any case, this is obviously (to us 50 years later) due to a past interaction with the diffuse material, counter-tail or ejected material being tidal plumes from the interaction. The question remains; what did the interacting? The MCG says of it: "Interacting. The tail 0.6 arcmin long is directed away from the galaxy 18 mag, and is at 1.4 arcmin north." That would indicate they don't see the tail .6' tail reaching all 1.4' to the galaxy? I don't follow this comment as it is obviously connected. Even more interesting this dates to 1963 before Arp's atlas was published and before many of the images were taken yet he never mentioned interaction being involved with his entries that clearly were due to interaction. Still, this doesn't answer the question of what did the interacting? It is over twice the distance to IC 421 by redshift so that galaxy is ruled out. NPM1G -07.0197 is the same distance, much smaller and looks pretty much undisturbed. There is an odd puff in its outer halo sort of on the side toward VV848. Still, could such a small galaxy do this to a much larger one? If the large galaxy is low density it could but that doesn't appear the case here. The only other candidate is LEDA 3080980 10 minutes north and well out of my frame. It is even smaller and less disturbed so definitely ruled out. The galaxy near NPM1G -07.0197 is 2MASX J05325377-0745054 and shows no sign of disturbance and has no distance data available if it did so I rule it out as well. Is this a merger? I can't find anything either way so it will have to remain a mystery. While it may appear smaller than IC 421 that's an illusion due to its large distance. It measures over 225,000 light-years cross including the plumes north and south.

Being in the zone of avoidance this field is very poorly studied and I found little to annotate but included what little I could find on it with redshift data.

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

Related Designations for IC0421

IC0423

IC 423 and IC 424 are a pair of reflection nebula in the region of Orion's belt two thirds of the way from Alnilam (middle star) and Mintaka (western belt star). I found no distances for these. Both seem to have tails pointing to Mintaka and heads pointing to more distant by angular measurement Alnilam. I'm going to go out on a limb and say that since their heads are toward Alnilam that it is the illuminating star. It is a B0Ia star at 1342 light-years per The Sky's database. Mintaka is a 09.5II star about 900 light-years distant. That puts it in front of most of the nebulae in the area with known distances.

IC 423 is sometimes called "The Teardrop Nebula". Considering how bad my imaging weather has been for months that seems appropriate. An interesting description of IC 423 going back to an image taken with the Crossley reflector and published in 1918 reads: "A very peculiar and interesting mass of diffuse nebulosity, 6' x 4'. The central part is vacant, giving the object the general appearance of a pear-shaped ring, rounded at the southern end and pointed at the northern end, which is directed approximately toward {delta} Orionis, 27' distant. There are flame-like protuberances on each side to the north. Quite faint." By today's imaging standards it isn't all that faint and certainly not "vacant" in the center. That region is much redder and somewhat dimmer but not empty. I couldn't find the Crossley image itself, unfortunately.

IC 424 has two stars in it. To my pareidolia challenged brain they look like slightly red and blue eyes. I turned the cropped image to south up. Is it a three-eared cat or a ghost? The Crossley description reads: "A smaller mass of diffuse nebulosity, somewhat resembling I 423; 2.5' x 1'; the sharper western endpoints to {delta} Orionis, 24' distant." Delta is Mintaka. To me, that's backwards. The Delta end is fuzzier, not sharper and fades away. Like IC423 it has a reddish darker core that sort of makes the nose of the cat or ghost.

Both were discovered by Williamina Fleming on June 27, 1888. A short bio of her reads: "Scottish-American astronomer. Abandoned by her husband, she was reduced to working as a maid. Her employer, a professor of astronomy at Harvard, was so dissatisfied with the work of his assistants that he claimed: "My maid could do a better job." And she did, becoming one of the most famous female astronomers of the 19th century, and an honorary member of the Royal Astronomical Society."

Conditions went down while this was taken. They were pretty good for the luminance data but transparency went bad on me for the color data. This meant I picked up nothing but noise for the faint nebulosity in the background. I didn't realize this until I went to process it too late to take more color data.

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

Related Designations for IC0423

IC0426

IC 426 is a reflection nebula in Orion, likely illuminated by Mintaka, the right hand star in Orion's belt. Like nearly all the nebulae in Orion, it is part of a vast cloud of dust and gas about 1300 light-years distant. The little piece that is IC 426 is about 2 light-years across. It is commonly seen in wide angle images of Orion's Belt -- the one in the sky not the one in "Men in Black". But no one seems to pay it any attention mentioning far more commonly seen objects in the field while ignoring poor IC 426. If it were anyplace else in the sky it would likely not be so overlooked. There appears to be a rather odd blue "jet" coming out of a blue star on the left side of the image. This is due to the star hitting a dust spec on the optical window in front of the sensor. It's not real.

The nebula was discovered by Williamina Flemming on June 27, 1888.

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

Related Designations for IC0426

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