Clear Skies
September 18th, 2022, 02:49 PM
This object of the week is a duplicate. A triplicate, in fact. I hope you will forgive me for that.
Intro
We all own star charts, books and a myriad of applications on our computers and smartphones. Thousands and thousands of objects are depicted and complete catalogs are just a tap on the screen, a mouse click, or a keystroke away. It's all charted and all of it is properly designated... or is it?
Some catalogs available to us amateur astronomers are hopelessly incomplete. Sure, we know about a propeller (https://www.google.com/search?q=propeller+nebula) in the Swan, even spaghetti (https://www.google.com/search?q=spaghetti+nebula) in the Bull. But what are these objects? The two that I used in this example are also known as Simeis 57 (https://simbad.u-strasbg.fr/simbad/sim-id?Ident=sim+57&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id) and 147 (https://simbad.u-strasbg.fr/simbad/sim-id?Ident=sim+147&submit=submit+id), respectively. Well... if there's a number 57, there must also be objects numbered 1 through 56. And if there's a number 147 there must also be numbers 58 through 146, perhaps numbers 148 and higher, too. Unfortunately, the little information that is easily accessible online, tells us little to none about the Simeis objects.
Simeis was an observatory (https://en.wikipedia.org/wiki/Simeiz_Observatory) on the southern tip of what is now occupied territory on the Crimea (https://en.wikipedia.org/wiki/Crimea). I knew about Gaze-Shajn objects ([GS55] (https://cds.unistra.fr/cgi-bin/Dic-Simbad?%5bGS55%5d) in SIMBAD) that also originate from the Crimea and I suspected that there was a connection with the Simeis objects. But lacking definite information, the catalog(s) remained mystical.
On the prowl for 'lost' celestial catalogs and the information and designations they could contain, I sent out some e-mails this summer. My calls did not remain unanswered. Dr. Tigran Magakian from Byurakan Observatory (https://www.bao.am/index.php) in Armenia (you know him from the Gyulbudaghian-Magakian nebulae) kindly replied and sent me information that made me gasp. The original Parsamian catalog (https://clearskies.eu/astronomy/articles/parsamian/), for starters. That was a fascinating, albeit relatively small project. What followed was a catalog published back in 1955 by Vera Fedorovna Gaze (https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwiSvLCExJ76AhWR7KQKHctxBtgQFnoECBAQAQ&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FVera_F edorovna_Gaze&usg=AOvVaw04aN9wENjYCyYUNALGezMd) and Grigory Abramovich Shajn (https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwj99vCKxJ76AhXN8qQKHaCNCNkQFnoECBEQAQ&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FGrigor y_Shajn&usg=AOvVaw2U5qoqtWED2VrWZKUucuHN). That one made me pick my jaw up from the floor. Because there they were: the Simeis objects, in an original Gaze-Shajn paper (https://clearskies.eu/astronomy/articles/gaze-shajn/). All of them? No, as I delved into the information I found the paper left 83 of a suspected total of 306 Simeis objects up for grabs. Of these 83, 66 were noted to be in the vicinity of other objects.
With this information in hand I set out for another internet search. What I stumbled upon was a post on a different forum (https://groups.google.com/g/sf-bay-tac/c/hoVRBnNfDdw/m/vtCEIbBrAQAJ) by our very own Akarsh Simha. In the post is a link to the archives of the Crimean Observatory (https://jn-craocrimea-ru.translate.goog/index.php/izvcrao/issue/archive?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=en&_x_tr_pto=wapp). Diving head first into that website it wasn't long before I found the same 1955 paper that Tigran Magakian had sent me. As the papers header translated to the ADS bibcode 1955IzKry..15...11G (https://ui.adsabs.harvard.edu/abs/1955IzKry..15...11G/abstract) (a 1955 paper from the Crimean Observatory, number 15, page 11) I was hopeful to find the missing Gaze-Shajn papers using the same interpretation for the other bibcodes. My hope was not in vain. In the observatory's 1950, 1951, 1952 and 1954 publications, I found the Gaze-Shajn papers I had been looking for. Tip of the hat to Akarsh!
As luck would have it, COVID hit me that week. It made me quite miserable for a few days, confining me to my couch and only being able to fiddle around on a laptop. Time well spent entering all designations and B1950 coordinates from the Gaze-Shajn papers into an Excel sheet. AstroPlanner (https://www.astroplanner.net) did the rest and with that I had a list of all but two of the Simeis objects with coordinates converted to J2000.0. Only numbers 302 & 303 remain elusive. The list is fascinating, to say the least. Work that remains to be done, is translating all of the papers' object notes from Russian to English. I am doing that one object at a time and I started with objects in Vulpecula, as I was already in the process of compiling Sharpless guides for that constellation. That has now become a combined object, as plenty of Sharpless objects are, as I can already tell, in fact Gaze & Shajn discoveries.
OOTW
Next, I turned to Cygnus and that brings me to this week's OOTW. It's the Veil Nebula. Again. The magnificent northern hemisphere supernova remnant that all of use have observed countless times. Yet I am pretty sure that none of us have ever seen it like this.
Over the years much has been written about this showpiece in Cygnus and Vulpecula. Delving into the Veil, away from the NGC and IC designations, there are many small filaments that are informally designated alphabetically (A through N), as published by Sky & Telescope in 2011 (https://skyandtelescope.org/wp-content/uploads/GD-Sept2011.pdf) & 2018 (https://skyandtelescope.org/astronomy-blogs/explore-night-bob-king/explore-veil-nebula/#attachment_255486361) and in an article (https://www.astronomy-mall.com/Adventures.In.Deep.Space/Dissecting%20the%20Veil%20Nebula.html) by Steve Gottlieb. Other designations did seem to originate from existing catalogs: Fleming's Triangle, off course, but there's also Simeis 3-188, Gaze-Shajn 222 and Simeis 3-210. Others are named, such as "the Funnel" and "the Thin Thread". I myself added the relatively bright, northernmost segment of the Veil complex to this collection as Veil Nebula O.
The 1955 Gaze-Shajn paper contains a labeled image for the Veil.
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As the catalog image unveils (...), many of the object that had informal designations attached to them in this century, have in fact had formal designations for almost 70 years(!).
Let's take a closer look. It may help to open the image below in a separate browser window as we go along. Alternatively, click here (https://clearskies.eu/csog/downloads/dsfootw2022/#38) to download it as a pdf observing guide.
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NGC6960 and nearby segments
Starting in the west, there's the famous "Witch's Broom" that goes by NGC6960. Gaze & Shajn did not assign a Simeis designation to it, but did include it in their 1952 paper as number 181 (GS 3-181). Be aware that this is not Simeis 181, it is simply the 181st entry in their 1952 paper: Simeis 181 = Gaze-Shajn 3-113 is an HII region in the constellation of Sagittarius that, a year later, was also cataloged by Stuart Sharpless as the 19th entry in his first catalog (Sh1-19) and the 22nd entry in his second (Sh2-22). The Gaze-Shajn note for NGC6960 in the Veil translates to "The famous bright filamentary nebula." In the 1955 paper it is included as part of the combined object Gaze-Shajn 5-221... you guessed it: the 221st entry in their 1955 paper. In it, the segments that are part of GS 5-221 are classified as "Entirely filamentary" and are described as "Filamentary nebula system with southward extension (Simeis 230)."
Before we head to Simeis 230, let's take a look at some extremely faint tendrils to the southwest of NGC6960. These are Simeis 222 (Gaze-Shajn 3-180), described as "A group of very faint thin filaments to the west of NGC6960, parallel to the nebula." It too is part of larger Gaze-Shajn 5-221.
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Taking in the bigger picture of the Veil complex, we can see multiple smaller, fainter filaments that appear to be extending towards the southeast from NGC6960. Two of these little fragments were dubbed segments C and D in the S&T articles. Closer inspection reveals more such segments. Together these form Simeis 230, with a catalog size of 60'x20' and the description "A band of filamentary formations that forms an extension of the NGC6960 nebula. It is elongated by an arc on the southeast side." Already in my observing blog for the night of 8-9 October 2021, I contemplated designating the northwestern most of these segments P & Q. With the information now revealed by the Simeis catalogs, I did not hesitate to name them as such. In addition, I designated three more of these segment in the east, segments R, S and T.
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The triangle
When we say Veil Nebula, we say Fleming's Triangle. To me, it is the most beautiful segment of them all. Yes, it's much fainter than the large outer loops, but the view with an OIII filter under dark skies is one that takes my breath away. The question remains what Wilhelmina Fleming cataloged as her discovery in 1904: is it the larger nebulous area as a whole, 40'x23' in size as measured by Gaze & Shajn, or is it only the smaller, triangularly shaped northeastern part? Until I get my hands on the original discovery notes, I can't tell. Regardless, the larger region is cataloged as Simeis 229 and is described as "A well-known group of thin filamentary formations located between NGC6960 and NGC6992. It narrows towards the south, forming a funnel-shape, and in the southern part, the thinnest long filaments Simeis 229 and Simeis 232 appear to flow out of it."
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I find it fascinating that Gaze & Shajn recognised that the object they designated Simeis 229 was in fact already discovered, albeit "anonymous", as noted for the larger region Gaze-Shajn 5-224 that includes Simeis 229: "A system of filamentary nebulae arranged in an arc parallel to the system NGC6960 and NGC6992. Includes anonymous (Simeis 229), Simeis 223, Simeis 225, Simeis 228, Simeis 232, Simeis 106, Simeis 238, Simeis 242."
North of Simeis 229 is an east-west elongated, detached and relatively large filament. Gaze & Shajn designated it Simeis 227 (GS 3-186): "A group of small thin filaments to the north of the large known funnel-shaped group Simeis 229 to the northeast of NGC6960." To the west is Simeis 223 (GS 3-182, formerly know as E): "Two intersecting short filaments to the northeast of NGC6960."
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Back to Simeis 229 of which the southern end tapers and forms what (visually) appears to be a funnel, or the tip of a spout if you will, that is interrupted in the middle. Interestingly enough, the 2018 S&T article (https://skyandtelescope.org/astronomy-blogs/explore-night-bob-king/explore-veil-nebula/) explicitly names a funnel, too. But the position of the S&T funnel is further south, matching the position of Simeis 228, described by Gaze & Shajn as "A double thin filament, elongated from north to south, the northern part is adjacent to Simeis 229." Judging by the catalog size of 20' and the B1950 position, this is a match for what was depicted in the S&T article. Therefor, I have decided to stick with the "Funnel" nickname for this very faint, double-segmented section to the south of Simeis 229, even when the southern part of Simeis 229 is much brighter and very Funnel-like, too.
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Further south, things continue to get more interesting. Extending southwards from Simeis 229 and south-southeast of Simeis 228 are two slivers. The eastern one much longer than the western is and until now only known as "the Thin Thread". It's Simeis 106, a degree long "thin, very long filament, stretched from north to south, which can also be considered as three separate filaments in series adjacent to each other."... in SIMBAD, this Simeis object is considered to be "defined nowhere (https://cds.unistra.fr/cgi-bin/Dic-Simbad?SIM)". Three adjacent filaments can indeed be seen where Simeis 106 springs out in the north. The western most of these extends directly from "the Funnel" (Simeis 228). The central sliver carries its own Simeis designation: nr. 232, "A thin, very sharp filament." Based on this description and the visual appearance of this short but very thin segment, I believe it is only fitting to dub this one "the Razor".
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To the west-southwest of "the Razor" that is Simeis 232, is a larger segment. It's Simeis 225, "A group of very faint interlacing filaments."
Tracing Simeis 106 towards the south, "the Thin Thread" fans out. That region earned the designation Simeis 235: "In the southern part of the filament Simeis 106, a group of weak thin fibers adjoins it, ending with some thickening in the south part." To the east it is flanked by faint Simeis 238 and Simeis 242 further east, that we used to call segment B.
As mentioned for Simeis 229, the filaments to the north and south of it are grouped together with it into a single Gaze-Shajn object: 5-224.
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Before we head in the direction of Vulpecula, let's stop by the group of 4 Simeis objects that is Gaze-Shajn 5-222. It involves, from northwest to southeast, Simeis 224, 226, 231 & 235 "arranged in an arc parallel to NGC6960."
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Gaze-Shajn 5-222 is in fact one of the designations that was out in the public domain but, as the Simeis catalogs show, it does not involve the part to the north that we now know is Simeis 225.
The Southern Blowout Region
A Western arc - not designated by Gaze & Shajn - and an Eastern Arc that involves 3 Simeis objects. Best known of these is the relatively bright segment that involves the mag. 6.4 star SAO89241 (BD+29 04221). This segment was, up until now, known as Simeis 3-210. It's in fact Simeis 249, but the "3-210" designation isn't entirely incorrect as - you guessed it again - it is the 210th entry in the 1952 paper with the catalog noting a "thickening of filamentary formations around BD + 294221. At this point, the direction of the filaments changes, turning towards the south." I find this catalog note quite interesting, as it leaves no doubt that Gaze & Shajn were tracing the filaments of the Veil along with their apparent directions in space.
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As the catalog size for Simeis 249 is 8'x4', that leaves two moderately bright and detached segments, to the north-northeast and to the south-southwest of Simeis 249, without a designation. I was able to observe both, using no larger than a 14" scope and I therefor decided to informally designate them segments U & V, respectively. Another segment already designated K is to the southwest of segment V. In between V & K is fainter nebulosity. Together these 3 filaments form Simeis 245: "A group of thin small filaments stretching towards the southwest from BD + 29.4221°. This group forms a condensation in the middle part, to which the coordinates belong." The "condensation" Gaze & Shajn noted, is the segment that was designated K. To the south thereof, completing the Eastern Arc, is a faint, elongated and detached segment that is Simeis 243: "A band consisting of thin filaments forms the southernmost extension of the entire system of filamentary nebula system NGC6960-6992."
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The north
Back to the north, where 7 Veil segments are bundled into Gaze-Shajn 5-227: "Partially filamentary, structured with individual parts. A group of nebulae located approximately in an arc parallel to the system NGC6960 - NGC6992 (NGC6979? Simeis 237, Simeis 233, Simeis 247, Simeis 246, Simeis 239, Simeis 241)."
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Two of these segments have always been known as NGC6974 and NGC6979. The former received the designation Simeis 241 but no Simeis identifier was attached to NGC6979. The northern most segment in this group is one that I had designated segment O but that, as it turns out, is Simeis 233. As is the case for all other "lettered filaments", I will keep this designation as an object synonym. The same goes (from north to south) for Simeis 237, 239, 246 & 247 that were previously known only as F, M, G & L.
The east
The final sections of the Veil are in the east, where we find NGC6992, NGC6995, IC1340 and a few more, smaller segments. None of these made it as a Simeis object. However, NGC6992 & NGC6995 together made it into the first Gaze-Shajn paper as GS 1-15. Descriptions are included in the 1950, 1952 and 1955 papers: "A known filamentary nebula, apparently a predominantly hydrogen formation - Well-known filamentary nebulae, that are essentially one - classification: Entirely filamentary." Surprisingly, IC1340 was not mentioned at all. Perhaps Gaze & Shajn considered it to be a part of NGC6995?
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South of NGC6995 and IC1340 are three small and faint segments. The eastern has already been designated as filament N. To the west thereof are two fainter ones; I labeled them W and X.
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Finally, there is the bright "Southeastern Knot", a.k.a. Veil Nebula H. Surprisingly, as it is bright enough to observe even in smaller apertures, it did not receive a Simeis designation.
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The Veil in a nutshell
42 individually designated segments. 24 Simeis designations, of which 2 are for a group of objects and 1 is for the already designated filament NGC6974 (Simeis 241). In addition, there are 6 Gaze-Shajn groups and 14 segments that remain designated only by letters.
That's a heck of a lot to go and observe, in what is essentially a single supernova remnant covering about 3 degrees of sky. But in the end, this is an Object of the Week. So even if the Veil is familiar territory to you, get out there (again) and see how many you can glimpse. Be sure to report back!
Intro
We all own star charts, books and a myriad of applications on our computers and smartphones. Thousands and thousands of objects are depicted and complete catalogs are just a tap on the screen, a mouse click, or a keystroke away. It's all charted and all of it is properly designated... or is it?
Some catalogs available to us amateur astronomers are hopelessly incomplete. Sure, we know about a propeller (https://www.google.com/search?q=propeller+nebula) in the Swan, even spaghetti (https://www.google.com/search?q=spaghetti+nebula) in the Bull. But what are these objects? The two that I used in this example are also known as Simeis 57 (https://simbad.u-strasbg.fr/simbad/sim-id?Ident=sim+57&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id) and 147 (https://simbad.u-strasbg.fr/simbad/sim-id?Ident=sim+147&submit=submit+id), respectively. Well... if there's a number 57, there must also be objects numbered 1 through 56. And if there's a number 147 there must also be numbers 58 through 146, perhaps numbers 148 and higher, too. Unfortunately, the little information that is easily accessible online, tells us little to none about the Simeis objects.
Simeis was an observatory (https://en.wikipedia.org/wiki/Simeiz_Observatory) on the southern tip of what is now occupied territory on the Crimea (https://en.wikipedia.org/wiki/Crimea). I knew about Gaze-Shajn objects ([GS55] (https://cds.unistra.fr/cgi-bin/Dic-Simbad?%5bGS55%5d) in SIMBAD) that also originate from the Crimea and I suspected that there was a connection with the Simeis objects. But lacking definite information, the catalog(s) remained mystical.
On the prowl for 'lost' celestial catalogs and the information and designations they could contain, I sent out some e-mails this summer. My calls did not remain unanswered. Dr. Tigran Magakian from Byurakan Observatory (https://www.bao.am/index.php) in Armenia (you know him from the Gyulbudaghian-Magakian nebulae) kindly replied and sent me information that made me gasp. The original Parsamian catalog (https://clearskies.eu/astronomy/articles/parsamian/), for starters. That was a fascinating, albeit relatively small project. What followed was a catalog published back in 1955 by Vera Fedorovna Gaze (https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwiSvLCExJ76AhWR7KQKHctxBtgQFnoECBAQAQ&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FVera_F edorovna_Gaze&usg=AOvVaw04aN9wENjYCyYUNALGezMd) and Grigory Abramovich Shajn (https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwj99vCKxJ76AhXN8qQKHaCNCNkQFnoECBEQAQ&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FGrigor y_Shajn&usg=AOvVaw2U5qoqtWED2VrWZKUucuHN). That one made me pick my jaw up from the floor. Because there they were: the Simeis objects, in an original Gaze-Shajn paper (https://clearskies.eu/astronomy/articles/gaze-shajn/). All of them? No, as I delved into the information I found the paper left 83 of a suspected total of 306 Simeis objects up for grabs. Of these 83, 66 were noted to be in the vicinity of other objects.
With this information in hand I set out for another internet search. What I stumbled upon was a post on a different forum (https://groups.google.com/g/sf-bay-tac/c/hoVRBnNfDdw/m/vtCEIbBrAQAJ) by our very own Akarsh Simha. In the post is a link to the archives of the Crimean Observatory (https://jn-craocrimea-ru.translate.goog/index.php/izvcrao/issue/archive?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=en&_x_tr_pto=wapp). Diving head first into that website it wasn't long before I found the same 1955 paper that Tigran Magakian had sent me. As the papers header translated to the ADS bibcode 1955IzKry..15...11G (https://ui.adsabs.harvard.edu/abs/1955IzKry..15...11G/abstract) (a 1955 paper from the Crimean Observatory, number 15, page 11) I was hopeful to find the missing Gaze-Shajn papers using the same interpretation for the other bibcodes. My hope was not in vain. In the observatory's 1950, 1951, 1952 and 1954 publications, I found the Gaze-Shajn papers I had been looking for. Tip of the hat to Akarsh!
As luck would have it, COVID hit me that week. It made me quite miserable for a few days, confining me to my couch and only being able to fiddle around on a laptop. Time well spent entering all designations and B1950 coordinates from the Gaze-Shajn papers into an Excel sheet. AstroPlanner (https://www.astroplanner.net) did the rest and with that I had a list of all but two of the Simeis objects with coordinates converted to J2000.0. Only numbers 302 & 303 remain elusive. The list is fascinating, to say the least. Work that remains to be done, is translating all of the papers' object notes from Russian to English. I am doing that one object at a time and I started with objects in Vulpecula, as I was already in the process of compiling Sharpless guides for that constellation. That has now become a combined object, as plenty of Sharpless objects are, as I can already tell, in fact Gaze & Shajn discoveries.
OOTW
Next, I turned to Cygnus and that brings me to this week's OOTW. It's the Veil Nebula. Again. The magnificent northern hemisphere supernova remnant that all of use have observed countless times. Yet I am pretty sure that none of us have ever seen it like this.
Over the years much has been written about this showpiece in Cygnus and Vulpecula. Delving into the Veil, away from the NGC and IC designations, there are many small filaments that are informally designated alphabetically (A through N), as published by Sky & Telescope in 2011 (https://skyandtelescope.org/wp-content/uploads/GD-Sept2011.pdf) & 2018 (https://skyandtelescope.org/astronomy-blogs/explore-night-bob-king/explore-veil-nebula/#attachment_255486361) and in an article (https://www.astronomy-mall.com/Adventures.In.Deep.Space/Dissecting%20the%20Veil%20Nebula.html) by Steve Gottlieb. Other designations did seem to originate from existing catalogs: Fleming's Triangle, off course, but there's also Simeis 3-188, Gaze-Shajn 222 and Simeis 3-210. Others are named, such as "the Funnel" and "the Thin Thread". I myself added the relatively bright, northernmost segment of the Veil complex to this collection as Veil Nebula O.
The 1955 Gaze-Shajn paper contains a labeled image for the Veil.
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As the catalog image unveils (...), many of the object that had informal designations attached to them in this century, have in fact had formal designations for almost 70 years(!).
Let's take a closer look. It may help to open the image below in a separate browser window as we go along. Alternatively, click here (https://clearskies.eu/csog/downloads/dsfootw2022/#38) to download it as a pdf observing guide.
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NGC6960 and nearby segments
Starting in the west, there's the famous "Witch's Broom" that goes by NGC6960. Gaze & Shajn did not assign a Simeis designation to it, but did include it in their 1952 paper as number 181 (GS 3-181). Be aware that this is not Simeis 181, it is simply the 181st entry in their 1952 paper: Simeis 181 = Gaze-Shajn 3-113 is an HII region in the constellation of Sagittarius that, a year later, was also cataloged by Stuart Sharpless as the 19th entry in his first catalog (Sh1-19) and the 22nd entry in his second (Sh2-22). The Gaze-Shajn note for NGC6960 in the Veil translates to "The famous bright filamentary nebula." In the 1955 paper it is included as part of the combined object Gaze-Shajn 5-221... you guessed it: the 221st entry in their 1955 paper. In it, the segments that are part of GS 5-221 are classified as "Entirely filamentary" and are described as "Filamentary nebula system with southward extension (Simeis 230)."
Before we head to Simeis 230, let's take a look at some extremely faint tendrils to the southwest of NGC6960. These are Simeis 222 (Gaze-Shajn 3-180), described as "A group of very faint thin filaments to the west of NGC6960, parallel to the nebula." It too is part of larger Gaze-Shajn 5-221.
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Taking in the bigger picture of the Veil complex, we can see multiple smaller, fainter filaments that appear to be extending towards the southeast from NGC6960. Two of these little fragments were dubbed segments C and D in the S&T articles. Closer inspection reveals more such segments. Together these form Simeis 230, with a catalog size of 60'x20' and the description "A band of filamentary formations that forms an extension of the NGC6960 nebula. It is elongated by an arc on the southeast side." Already in my observing blog for the night of 8-9 October 2021, I contemplated designating the northwestern most of these segments P & Q. With the information now revealed by the Simeis catalogs, I did not hesitate to name them as such. In addition, I designated three more of these segment in the east, segments R, S and T.
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The triangle
When we say Veil Nebula, we say Fleming's Triangle. To me, it is the most beautiful segment of them all. Yes, it's much fainter than the large outer loops, but the view with an OIII filter under dark skies is one that takes my breath away. The question remains what Wilhelmina Fleming cataloged as her discovery in 1904: is it the larger nebulous area as a whole, 40'x23' in size as measured by Gaze & Shajn, or is it only the smaller, triangularly shaped northeastern part? Until I get my hands on the original discovery notes, I can't tell. Regardless, the larger region is cataloged as Simeis 229 and is described as "A well-known group of thin filamentary formations located between NGC6960 and NGC6992. It narrows towards the south, forming a funnel-shape, and in the southern part, the thinnest long filaments Simeis 229 and Simeis 232 appear to flow out of it."
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I find it fascinating that Gaze & Shajn recognised that the object they designated Simeis 229 was in fact already discovered, albeit "anonymous", as noted for the larger region Gaze-Shajn 5-224 that includes Simeis 229: "A system of filamentary nebulae arranged in an arc parallel to the system NGC6960 and NGC6992. Includes anonymous (Simeis 229), Simeis 223, Simeis 225, Simeis 228, Simeis 232, Simeis 106, Simeis 238, Simeis 242."
North of Simeis 229 is an east-west elongated, detached and relatively large filament. Gaze & Shajn designated it Simeis 227 (GS 3-186): "A group of small thin filaments to the north of the large known funnel-shaped group Simeis 229 to the northeast of NGC6960." To the west is Simeis 223 (GS 3-182, formerly know as E): "Two intersecting short filaments to the northeast of NGC6960."
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Back to Simeis 229 of which the southern end tapers and forms what (visually) appears to be a funnel, or the tip of a spout if you will, that is interrupted in the middle. Interestingly enough, the 2018 S&T article (https://skyandtelescope.org/astronomy-blogs/explore-night-bob-king/explore-veil-nebula/) explicitly names a funnel, too. But the position of the S&T funnel is further south, matching the position of Simeis 228, described by Gaze & Shajn as "A double thin filament, elongated from north to south, the northern part is adjacent to Simeis 229." Judging by the catalog size of 20' and the B1950 position, this is a match for what was depicted in the S&T article. Therefor, I have decided to stick with the "Funnel" nickname for this very faint, double-segmented section to the south of Simeis 229, even when the southern part of Simeis 229 is much brighter and very Funnel-like, too.
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Further south, things continue to get more interesting. Extending southwards from Simeis 229 and south-southeast of Simeis 228 are two slivers. The eastern one much longer than the western is and until now only known as "the Thin Thread". It's Simeis 106, a degree long "thin, very long filament, stretched from north to south, which can also be considered as three separate filaments in series adjacent to each other."... in SIMBAD, this Simeis object is considered to be "defined nowhere (https://cds.unistra.fr/cgi-bin/Dic-Simbad?SIM)". Three adjacent filaments can indeed be seen where Simeis 106 springs out in the north. The western most of these extends directly from "the Funnel" (Simeis 228). The central sliver carries its own Simeis designation: nr. 232, "A thin, very sharp filament." Based on this description and the visual appearance of this short but very thin segment, I believe it is only fitting to dub this one "the Razor".
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To the west-southwest of "the Razor" that is Simeis 232, is a larger segment. It's Simeis 225, "A group of very faint interlacing filaments."
Tracing Simeis 106 towards the south, "the Thin Thread" fans out. That region earned the designation Simeis 235: "In the southern part of the filament Simeis 106, a group of weak thin fibers adjoins it, ending with some thickening in the south part." To the east it is flanked by faint Simeis 238 and Simeis 242 further east, that we used to call segment B.
As mentioned for Simeis 229, the filaments to the north and south of it are grouped together with it into a single Gaze-Shajn object: 5-224.
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Before we head in the direction of Vulpecula, let's stop by the group of 4 Simeis objects that is Gaze-Shajn 5-222. It involves, from northwest to southeast, Simeis 224, 226, 231 & 235 "arranged in an arc parallel to NGC6960."
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Gaze-Shajn 5-222 is in fact one of the designations that was out in the public domain but, as the Simeis catalogs show, it does not involve the part to the north that we now know is Simeis 225.
The Southern Blowout Region
A Western arc - not designated by Gaze & Shajn - and an Eastern Arc that involves 3 Simeis objects. Best known of these is the relatively bright segment that involves the mag. 6.4 star SAO89241 (BD+29 04221). This segment was, up until now, known as Simeis 3-210. It's in fact Simeis 249, but the "3-210" designation isn't entirely incorrect as - you guessed it again - it is the 210th entry in the 1952 paper with the catalog noting a "thickening of filamentary formations around BD + 294221. At this point, the direction of the filaments changes, turning towards the south." I find this catalog note quite interesting, as it leaves no doubt that Gaze & Shajn were tracing the filaments of the Veil along with their apparent directions in space.
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As the catalog size for Simeis 249 is 8'x4', that leaves two moderately bright and detached segments, to the north-northeast and to the south-southwest of Simeis 249, without a designation. I was able to observe both, using no larger than a 14" scope and I therefor decided to informally designate them segments U & V, respectively. Another segment already designated K is to the southwest of segment V. In between V & K is fainter nebulosity. Together these 3 filaments form Simeis 245: "A group of thin small filaments stretching towards the southwest from BD + 29.4221°. This group forms a condensation in the middle part, to which the coordinates belong." The "condensation" Gaze & Shajn noted, is the segment that was designated K. To the south thereof, completing the Eastern Arc, is a faint, elongated and detached segment that is Simeis 243: "A band consisting of thin filaments forms the southernmost extension of the entire system of filamentary nebula system NGC6960-6992."
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The north
Back to the north, where 7 Veil segments are bundled into Gaze-Shajn 5-227: "Partially filamentary, structured with individual parts. A group of nebulae located approximately in an arc parallel to the system NGC6960 - NGC6992 (NGC6979? Simeis 237, Simeis 233, Simeis 247, Simeis 246, Simeis 239, Simeis 241)."
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Two of these segments have always been known as NGC6974 and NGC6979. The former received the designation Simeis 241 but no Simeis identifier was attached to NGC6979. The northern most segment in this group is one that I had designated segment O but that, as it turns out, is Simeis 233. As is the case for all other "lettered filaments", I will keep this designation as an object synonym. The same goes (from north to south) for Simeis 237, 239, 246 & 247 that were previously known only as F, M, G & L.
The east
The final sections of the Veil are in the east, where we find NGC6992, NGC6995, IC1340 and a few more, smaller segments. None of these made it as a Simeis object. However, NGC6992 & NGC6995 together made it into the first Gaze-Shajn paper as GS 1-15. Descriptions are included in the 1950, 1952 and 1955 papers: "A known filamentary nebula, apparently a predominantly hydrogen formation - Well-known filamentary nebulae, that are essentially one - classification: Entirely filamentary." Surprisingly, IC1340 was not mentioned at all. Perhaps Gaze & Shajn considered it to be a part of NGC6995?
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South of NGC6995 and IC1340 are three small and faint segments. The eastern has already been designated as filament N. To the west thereof are two fainter ones; I labeled them W and X.
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Finally, there is the bright "Southeastern Knot", a.k.a. Veil Nebula H. Surprisingly, as it is bright enough to observe even in smaller apertures, it did not receive a Simeis designation.
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The Veil in a nutshell
42 individually designated segments. 24 Simeis designations, of which 2 are for a group of objects and 1 is for the already designated filament NGC6974 (Simeis 241). In addition, there are 6 Gaze-Shajn groups and 14 segments that remain designated only by letters.
That's a heck of a lot to go and observe, in what is essentially a single supernova remnant covering about 3 degrees of sky. But in the end, this is an Object of the Week. So even if the Veil is familiar territory to you, get out there (again) and see how many you can glimpse. Be sure to report back!