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Confusing NGC object naming

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#1 Mike Phillips

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Posted 16 August 2014 - 11:06 PM

I photographed NGC 6445 per the charts I was reading.  Astronometry.net solves it as NGC 6445 (http://nova.astromet...ted_full/816041), which is labeled as "The Little Gem".  I'm ok with that.  Here's where I got confused.  NGC 6818 is the Little Gem per this Wikipedia entry (http://en.wikipedia.org/wiki/NGC_6818)

 

and... http://server7.wikis... 6445&locale=EN

 

Finally this just confuses me: http://www.astrobin.com/44175/0/

 

I'm thinking astrobin uses the same underlying database name matches that astrometry.net uses and is in error somehow.

 

TIA,

 

Mike



#2 Man in a Tub

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Posted 17 August 2014 - 01:16 AM

http://www.nightskya...om/dsoNames.jsp

 

 

Some DSOs share the same name, others have multiple names.

 

Scroll down to "Little Gem" — both NGC 6818 and NGC 6445 share a "nickname."

 

At the link above, the SEDS (Students for the Exploration and Development of Space) here link went 404 some time ago.



#3 rutherfordt

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Posted 17 August 2014 - 07:13 AM

This illustrates the problem of using common names for things-- different people use different names for the same thing-- it leads to confusion.  I never use common names for things-- I only use catalog numbers.  An NGC number has only one meaning no matter who or where you are.

 

Tom


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#4 Illinois

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Posted 17 August 2014 - 07:38 AM

I use Messier and NGC numbers and rare use name. I do famous name if my friend or family don't know much about astronomy like Seven Sisters, Great Orion Nebula, Northern American Nebula, Veil Nebula, etc.



#5 BrooksObs

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Posted 17 August 2014 - 07:58 AM

As several other posters have indicated this "informal popular naming" of countless NGC objects, often with duplicate or highly similar names repeated, has resulted in an obvious degree of confusion.

 

There were only a handful of prominent objects that carried widely accepted/universally recognized popular names until about 20 years ago. Subsequent to that many folks in the Deep Sky Observing community decided to begin attaching their own favorite appellations to objects. These they began including if they happened to write articles, or maintain websites. This spread to the general observer community until just about everyone was trying to get their clever idea for a name attached to some obscure object.  The nonsense then even spread to a host of asterisms! Now we have simply a torrent of silly names informally assigned to countless objects, some having several such names.

 

I think that most serious observers tend to avoid these new names just to keep things straight when referring to an object in discussions to avoid confusion, but do as you please.

 

BrooksObs


Edited by BrooksObs, 17 August 2014 - 09:48 AM.


#6 Mike Phillips

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Posted 17 August 2014 - 10:49 AM

I guess I wanted to be sure I knew what object I was looking at.  I agree wholeheartedly that the catalog designation is the only way to go.  Thanks all!

 

Mike



#7 David Knisely

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Posted 18 August 2014 - 01:54 AM

I see nothing to get terribly upset about when it comes to various possible names for deep-sky objects, as long as the proper catalog IDs are also provided up-front (and as long as no one claims that name is somehow "official", as it usually can never really be).  There have been multiple names for some of the most promient deep-sky objects way back *many* decades ago, so it is to be expected.  M33 went by several names like "the Pinwheel Galaxy", a name it shared with both M101 and M99.  "The Spindle Galaxy" also referred to more than one object:  NGC 5866 and NGC 3115.  "The Little Gem" has always been NGC 6818 to me ever since I first heard of it many years ago (and SIMBAD responds to that name with the NGC 6818 ID), so I don't know about it being associated with another nebula.  As long as someone says, "NGC 6818" or "the little planetary north of Barnard's Galaxy", I'll know what they are talking about. 

 

I have sort of "named" a few myself for my own use, and one or two of these names actually have caught-on a bit with others.  One name's appearance sort of caught me by accident, as during one observing report, I mentioned that the fine planetary nebula NGC 3242 in Hydra at very high power looked a little like the old logo for the Columbian Broadcasting Network ("the CBS Eye").  Now, I see that the SEDS list has that CBS Eye name listed for that very object (who'd a thunk?)!  Another one I ran into when looking over the old Palomar Sky Survey plates on laserdisk (yea, that kind of dates me a little, as it was 1989) and noted one planetary nebula that looked like a pair of headphones or earmuffs.  That one (the big planetary PNG 164.8 + 31.1 (or Jones-Emberson 1) in Lynx) I called "the Headphones", and after I finally tracked it down in my 10 inch with filters, I did write about it both in our club newsletter and on-line.  Even though it is a fairly faint and somewhat obscure target, I have since heard the object referred to by that name serveral times on-line, so maybe a few people do think it may look a little like that common audio appliance.  Around 1970, someone in our club (a certain Lincoln East High School student) who was viewing the fine open cluster NGC 6939 in Cepheus in an old RV-6 called it, "The Seacrest Cluster", as it resembled a set of stadium lights at Lincoln Nebraska's Seacrest Field.  That name never caught on with me (I didn't live in Lincoln), so in my notes, I called it "The Right Angle Cluster", for the row and central column of stars that forms a very visible right angle in that group.   When doing my first nebula survey with my 10 inch and my "new" OIII filter (around 1988), in Cassiopeia, I ran into a large faint complex of nebulosity plotted but unlabled on the old Skalnate-Pleso atlas ("Atlas of The Heavens" Atlas Coeli 1950.0) that had three arcs running away from a box-like mass.   Not knowing what it was at the time, I called this complex, "the fingers", as on the atlas, it looked like fingers extending away from a hand, although again, this name was more for my use than someone else.  It wasn't plotted on the 1st edition of Sky Atlas 2000, so I kept that "name" as its primary identifier for over a decade until I finally tracked down a catalog that had it.  Now, while I "officially" refer it as (Sharpless) Sh2-157, "the fingers" still sticks in my mind whenever I go looking for it.            

 

For a lot of the "common" names, the list below is fairly complete:

 

http://messier.seds....pp/d-names.html

 

Otherwise, I will only quote the Bard; "What's in a name? That which we call a rose, by any other name would smell as sweet;"

 

Enough said.  Clear skies to you.



#8 Tony Flanders

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Posted 18 August 2014 - 06:15 AM

I see nothing to get terribly upset about when it comes to various possible names for deep-sky objects, as long as the proper catalog IDs are also provided up-front (and as long as no one claims that name is somehow "official", as it usually can never really be).


Yep, that pretty much sums it up.

For what it's worth, a number of objects are almost always known by their nicknames. For instance, how many people know the catalog numbers of each section of the Veil Nebula, and know which section has which number? Not many! Instead, we call the whole complex "The Veil." Likewise the Rosette Nebula.

I do know the catalog numbers of each half of the Double Cluster, but I still think of it as The Double Cluster.

With asterisms -- which I love -- there's nothing but a nickname. Not being real, they're not found in professional catalogs.

#9 Starman1

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Posted 18 August 2014 - 03:49 PM

Doesn't the SAC have a long list of asterisms on their download site, most with names?

What I object to most is that many, if not most, nicknames are from photographic images, and do not resemble the

visual image in a telescope.

I mean, "Sombrero" galaxy?  Doesn't look like a Sombrero at all.  But it does look kind of like a cracked lens.

"Omega" Nebula?  "Swan" Nebula?  or "Checkmark" Nebula?  Depends on the scope, the magnification, the imagination.

Frankly, I'm bothered by using nicknames at all.  In a way, it's as if we're trying to justify our hobby by calling the objects names that

might make non-astronomers want to look--sort of an apology for the science behind the objects.

It might be better for the science of astronomy if we said, "M8: Large emission nebula with un-lit dark gas where hundreds

of stars have been born (that you can see) and are still forming" instead of "The Lagoon" Nebula (it doesn't resemble a Lagoon at all).

Maybe then people would have a better understanding of what they're looking at through the eyepieces.


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#10 csrlice12

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Posted 18 August 2014 - 03:54 PM

Using that logic though, why do we name constellations? 


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#11 Tony Flanders

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Posted 21 August 2014 - 11:44 AM

Using that logic though, why do we name constellations?


That decision was made for us several thousand years ago.

#12 Jon Isaacs

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Posted 21 August 2014 - 12:50 PM

Using that logic though, why do we name constellations? 

 

:waytogo:

 

Personally I am OK with the informal nicknames or the the more official designations but I have an easier time remembering the informal names. What I do remember most easily is the location in the sky and the object itself, that is what is most real to me.  The names, official or informal,  are conveniences for communication purposes.

 

Just what was the official designation for the Table of Scorpius?  NGC6231??? Just looked it up, got it right for once..

 

I do think the informal names add a bit of romance and are more descriptive.. nothing wrong with that... as a science type when the sun is up..  in the lab, in discussions, informal names are used..  it a paper, technical names are used.. I am not writing papers for Cloudy Nights.. 

 

Jon



#13 Starman1

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Posted 21 August 2014 - 04:16 PM

Jon,

I never heard that name for that section of Scorpius until your post.  I have heard the area called "The False Comet" though because of how it appears in binoculars.



#14 rutherfordt

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Posted 22 August 2014 - 07:02 AM

I think the two posts above illustrate the whole issue, don't they?  Two different names for the same thing (and I had never heard of either of them).

 

Tom



#15 Jon Isaacs

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Posted 22 August 2014 - 09:07 AM

I think the two posts above illustrate the whole issue, don't they?  Two different names for the same thing (and I had never heard of either of them).

 

Tom

 

Tom:

 

Have you ever heard of C76, Mellote 153 or Collinder 315?  Multiple names for the same object.. 

 

Jon



#16 Tony Flanders

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Posted 22 August 2014 - 09:27 AM

I think the two posts above illustrate the whole issue, don't they?  Two different names for the same thing (and I had never heard of either of them).
 
Tom

 
Tom:
 
Have you ever heard of C76, Mellote 153 or Collinder 315?  Multiple names for the same object.. 
 
Jon


True, but that's not quite fair, because there's a convention that you always use NGC numbers when one is available. So this object would always be called NGC 6231, never Mel 153. (The only important exception is Messier objects.)

However, there are plenty of important objects that have neither an NGC nor an IC designation. For instance, the famous asterism Collinder 399, better known as the Coathanger or Brocchi's Cluster. To say nothing of the Hyades -- though that's a special case because the name is 2,500 years old and well known and established beyond all reproach.

Multiple names is just a fact of life in astronomy. Fortunately, Google has made disambiguation easier than ever before -- not that it's easy even now.

#17 Starman1

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Posted 22 August 2014 - 09:46 AM

Tony's right.

Many galaxies I look into have as many as 8 or more different designations due to the numbers of different catalogs they appear in.

And once you get away from the NGC/IC, there doesn't appear to be a "pecking order" in terms of name preferences, so you're just as likely

to see it referred to as one or as another: UGC, MCG, PGC, ESO, CGCG,Arp, etc. 

I'm really grateful for NED and SIMBAD.



#18 desertstars

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Posted 23 August 2014 - 10:34 AM

I belong to an online gardening group that has this same conversation on a regular basis, regarding names for plants. The general practice in that case is to call it by whatever common name you're familiar with, followed by the Latinate binomial in parentheses. (That's not 100% certain, of course, since the binomials do change as research into plant taxonomy makes inevitable changes.) I returned to amateur astronomy with that habit in place, which is why I tend to follow a "common name" (when I use one in my log) with an NGC/IC designation if one exists. For the observing I do, it's very rare that there isn't an NGC/IC number. When that has happened, I record the object the same way, with whatever official catalog designation I find on the chart I use. I treat alternate listings (Collinder, etc.) like common names, and follow them with NGC designations. It works well for me, and when I share observations with other observers, people seem to know what I mean.



#19 jethro

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Posted 23 August 2014 - 10:53 AM

I basically do the same as I log my obsevations.

Though, since I'm still very new at this, I write down all NGC/IC designations and other common names with the object.

It helps me remember - sometimes- all that stuff I have crammed into the old grey matter.




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