Jeff Young
Post Laureate
Reged: 08/04/05
Posts: 4122
Loc: Ireland
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A comment from Tony Flanders on another thread got me thinking:
Quote:
I would call it UGC 8462, by the way. My rule of thumb for chosing among a typical galaxy's 8 to 10 designations is Messier first, NGC second, UGC third, and only then use the PGC designation. Many people would also use the MCG designation (MCG 9-22-64) in preference to the PGC. Or CGCG 271-42.
I use roughly the same precedence for galaxies, except that I love to hunt Arps so I'll usually use the Arp # even before the NGC #:
M
Arp
NGC/IC
UGC
MCG
PGC
And for galaxy clusters:
HCG (Hicksons)
Abell
But I've had more trouble with other object classes. In particular, PNs and Quasars/Blazars.
My current PN pecking order is:
M
Minkowski
Abell
NGC/IC
PK
Je (I'm not even sure what this one is, but the Headphones is Je1, although I currently have it logged under PK)
PNG
And for AGNs, my only real rule is avoid QSO:
any of: Markarian, 3C (is there also a 2C?), Zwicky, APM
QSO (is there also a QAGN?)
What do others use, particularly in the last two categories?
-- Jeff.
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Nikon 18x70s / UA Millennium Colorado:
Solarscope SF70 / TV Pronto / AP400QMD Coronado SolarMax40 DS / Bogen 055+3130
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JakeSaloranta
sage
Reged: 09/18/08
Posts: 237
Loc: Sisu, Sauna, Sibelius...
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Naming deep sky objects properly is annoying at best. You can do it the "real" way ie. who discovered the object first it. Of course it takes time to figure out who discovered what first where.
Then you get to the thinking part. Like Messiers should be called Hodierna XX instead of the Messier designation and M45 should be called Pleiades... and M31 Andromeda Galaxy or something Persian... who knows!
So for example this way Messier gets dibs on NGCs and Minkowski on PKs. 3C (1959) on Markarian (1989?) and on and on we go.
Just takes a bit time to Google everything and be on top of things which makes it annoying...
JE1 = Jones-Emberson 1 in Lynx I think.
And yes there is 2C as well as 3C. Here: http://en.wikipedia.org/wiki/Second_Cambridge_Catalogue_of_Radio_Sources
/Jake
Edited by JakeSaloranta (10/19/09 12:37 PM)
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Tony Flanders
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There's overwhelming reason to use NGC and IC labels in preference to everything else but Messier numbers. In fact, the IAU recommends using them even in preference to Messier numbers -- a practice that's followed perhaps 50% of the time in the professional literature but hardly ever in the amateur literature.
Why is the use of NGC and IC labels so compelling? First of all, it's almost universal practice. If somebody talks about PK 36-57.1, 999 out of 1000 astronomers (amateur and professional) will have to consult their cross-reference tables. Call it NGC 7293 and all professionals (and many amateurs) will instantly know that you mean the huge, nearby planetary nebula in Aquarius often known as the Helix.
Using popular names is fine if and only if the NGC designation is given too.
In addition, the NGC and IC are very old and well established, though of course there's still debate about some of the entries. And they give you nice, simple, short numbers that are easy to remember and easy to label on charts. Especially since NGC is so widespread that it's common convention just to use the number and leave the "NGC" implicit.
Beyond that -- it's a wild, chaotic world out there!
Stars, of course, are equally problematic.
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Tony Flanders
First and foremost observing love: naked eye.
Second, binoculars.
Last but not least, telescopes.
And I sometimes dabble with cameras.
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Hrundi
Pooh-Bah
Reged: 02/06/08
Posts: 1247
Loc: Estonia
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I'm not sure the IAU has a preference in regard to messier, IC and NGC numbers.
In fact, as far as I can see, it also leaves full blown names as a viable option for objects of particular note.
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JakeSaloranta
sage
Reged: 09/18/08
Posts: 237
Loc: Sisu, Sauna, Sibelius...
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Quote:
Using popular names is fine if and only if the NGC designation is given too.
Amen to that! These days every other galaxy and nebula does have a "cool" nickname given by a random observer/photographer but it is quite common to leave out the actual NGC, IC, whatever designation!
I find this highly annoying when browsing our astronomy magazine where most of the objects are just labeled with a nickname and nothing more.
I need to go out and chill for a bit 
/Jake
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Cygnus_x1
Sketcher Extraordinaire
Reged: 11/17/04
Posts: 2400
Loc: 50N - too far north!
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Quote:
Quote:
Using popular names is fine if and only if the NGC designation is given too.
Amen to that! These days every other galaxy and nebula does have a "cool" nickname given by a random observer/photographer but it is quite common to leave out the actual NGC, IC, whatever designation!
I find this highly annoying when browsing our astronomy magazine where most of the objects are just labeled with a nickname and nothing more.
I need to go out and chill for a bit
/Jake
I totally agree, Jake! The nicknames are all well and nice but mean nothing if the NGC designation, etc, is left out.
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Visual Deep Sky Observing - NEW website
Observing blog
My astronomy event photos on Flickr
12 inch Dob
8 inch Celestron C8 Newtonian
4 inch Meade SCT
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Various TeleVue eyepieces
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Jeff Young
Post Laureate
Reged: 08/04/05
Posts: 4122
Loc: Ireland
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I don't know, folks. What I'm usually looking for is the most communicative (dare I say evocative?) ID.
Let me give some examples. I don't think anyone would find fault with the "Veil Nebula". But I wouldn't know which side you were talking about, nor do I ever remember which is which between NGC6960 and 6992/95. But if you said "Witch's Broom" or "Waterfall", I'd know instantly what you meant.
And even without bringing names into the question, type-specific catalog IDs carry more info than general ones.
For instance, if I mentioned Arp6 in an observing report, everyone would know I was talking about a peculiar galaxy, or perhaps an interacting group of galaxies. But who would know off the top of their head what NGC2537 was? (We'll ignore the "Bear Paw" name for now.)
And what about Pal9? I'd know immediately that we're talking about a dim globular. But NGC6717? I might know that one, but I might not.
Perhaps all this means that there's no "rule of precedence" anyway. Each target has its own, unique set of "most known" or "most communicative" identifiers.
-- Jeff.
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Nikon 18x70s / UA Millennium Colorado:
Solarscope SF70 / TV Pronto / AP400QMD Coronado SolarMax40 DS / Bogen 055+3130
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starrancher
professor emeritus
Reged: 06/09/09
Posts: 620
Loc: Northern Arizona
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Hey , now there ya go !
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LXD75 AR5
LXD75 SN8
Series 4000 Plossls
Misc. other stuff
Fort Rock , Az .
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Jim Curry
sage
Reged: 10/29/07
Posts: 434
Loc: Maine
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There are a few names that have been passed that are generally recognized. I agree, the habit of writers to name objects has accelerated over the last 10 years or so. I even saw recently I believe a galaxy named after King So&So. That was it, I don't think I even finished the article. I don't know if it's an overactive immagination, hypothermia or oxygen starvation but it is getting old.
Jim (rant over)
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Vixen 140 refractor
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scopethis
professor emeritus
Reged: 05/30/08
Posts: 638
Loc: Kingman, Ks
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My ID beef--I wish all photos of deep sky objects in magazines had to be labeled. Seeing a pix of a great object either in an ad or column and not knowing what the ID is drives me crazy; cause I might want to locate and see the object, but what's it called??
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Tony Flanders
Post Laureate
Reged: 05/18/06
Posts: 3469
Loc: Cambridge, MA, USA
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Quote:
I don't know, folks. What I'm usually looking for is the most communicative (dare I say evocative?) ID.
Let me give some examples. I don't think anyone would find fault with the "Veil Nebula". But I wouldn't know which side you were talking about, nor do I ever remember which is which between NGC6960 and 6992/95.
The Veil is a special case, because it has multiple NGC and IC identifiers for its numerous components. Likewise the Rosette. But those are the exceptions that prove the rule.
Having said that, it's easy to know which arc is 6960 and which is 6992/6995 if you remember that the NGC is numbered in RA order -- yet another reason to use those numbers!
Anyway, when an object has a widely known popular name, it's obviously helpful to use it -- in addition to the NGC number. The "standard" name for that big planetary in Aquilla is "NGC 7293, the Helix Nebula" or "the Helix Nebula, NGC 7293." That way, nobody loses.
Quote:
But if you said "Witch's Broom" or "Waterfall", I'd know instantly what you meant.
Anybody familiar with the Veil's appearance through a big scope could guess what the Witch's Broom is, but I've never heard of the Waterfall. So please don't use names like that without further identification!
How about something like "the middle of the eastern arc?"
The bottom line is that these supposedly evocative and easily remembered names are *not* universally recognized. So if you actually want people to understand what you're saying, rather than just demonstrating how poetic you are, always use the NGC number. Having done that, there's no harm in adding as many other names as you like.
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Tony Flanders
First and foremost observing love: naked eye.
Second, binoculars.
Last but not least, telescopes.
And I sometimes dabble with cameras.
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Jeff Young
Post Laureate
Reged: 08/04/05
Posts: 4122
Loc: Ireland
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Quote:
Having said that, it's easy to know which arc is 6960 and which is 6992/6995 if you remember that the NGC is numbered in RA order -- yet another reason to use those numbers!
....
How about something like "the middle of the eastern arc?"
He he. At this point I have to confess to being one of those new-generation GoTo guys. I haven't the foggiest idea whether the thin, broom-like one with the bright star in the middle is the eastern or western arc. I just type one NGC ID in, and if it's the wrong one, I try the other one.
For what it's worth, on my sketch from last year, I included only the NGC ID:
Rats, I also see that I didn't include the cardinal directions on that sketch, an omission I find even more annoying than using the wrong name/ID.
Most of my sketches, though, would have the common name under the NGC ID (and have cardinal directions just outside the FoV):
Cheers,
-- Jeff.
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Nikon 18x70s / UA Millennium Colorado:
Solarscope SF70 / TV Pronto / AP400QMD Coronado SolarMax40 DS / Bogen 055+3130
APM MC1610 / Tak FC-100 / AP1200GTO Tak Mewlon 250 / AP600EGTO
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stevecoe
"Astronomical Tourist"
Reged: 04/24/04
Posts: 2648
Loc: Arizona, USA
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All that I ask is for the NGC or PK or Arp number to be given along with the "cutsy" nickname. No, I don't know Arp numbers off the top of my head, but I can look them up. I can't look up "Pinwheel" galaxy because that name has been applied to three different galaxies.
We need to train people to provide enough information about the object they are discussing so there is no ambiguity about the galaxy or nebula they are observing or drawing.
Clear skies;
Steve Coe
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TeleVue 102 refractor on CGEM mount
10 inch f/4.7 Newtonian
Author "Deep Sky Observing" Springer-Verlag
Author "Nebulae and How to Observe Them" Springer
Canon Xt astrocamera with Hutech modification
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Jeff Young
Post Laureate
Reged: 08/04/05
Posts: 4122
Loc: Ireland
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I agree whole-heartedly with Steve, but I'd like to steer this thread back away from names.
My original theme was the precedence of different IDs, rather than names vs. IDs.
For instance, there's the brightest quasar in the known universe -- which doesn't even have a name. 
But what do I write on the top of my sketch?
QSO J0831+5245
IRAS F08279+5255
2MASS J08314169+5245174
APM 08279+5255
QSO B0827+5255
VV2000 J083141.6+524518
I've done enough research on this one that I'm pretty sure the answer is APM 08279+5255, although SIMBAD seems to prefer QSO J0831+5245. But how in the world would I know that (aside from Googling each ID and seeing which had the most hits)?
3C66A is another common target, but goodness, SIMBAD lists 37 different IDs for it!
I kind of liked QSO for quasars (as it's fairly complete), and PK for planetaries (although PNG is even more complete). But more people will recognize 3C66A and Abell12 than QSO B0219+428 and PK PK198-06.1.
What about M2-9 vs. PK010+18.2? Are Minkowski IDs well-enough known, or might I just as well use the PK ID?
-- Jeff.
--------------------
Nikon 18x70s / UA Millennium Colorado:
Solarscope SF70 / TV Pronto / AP400QMD Coronado SolarMax40 DS / Bogen 055+3130
APM MC1610 / Tak FC-100 / AP1200GTO Tak Mewlon 250 / AP600EGTO
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David Knisely
Postmaster
Reged: 04/19/04
Posts: 8290
Loc: Beatrice, Nebraska
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Quote:
I agree whole-heartedly with Steve, but I'd like to steer this thread back away from names.
My original theme was the precedence of different IDs, rather than names vs. IDs.
For instance, there's the brightest quasar in the known universe -- which doesn't even have a name.
But what do I write on the top of my sketch?
QSO J0831+5245
IRAS F08279+5255
2MASS J08314169+5245174
APM 08279+5255
QSO B0827+5255
VV2000 J083141.6+524518
I've done enough research on this one that I'm pretty sure the answer is APM 08279+5255, although SIMBAD seems to prefer QSO J0831+5245. But how in the world would I know that (aside from Googling each ID and seeing which had the most hits)?
3C66A is another common target, but goodness, SIMBAD lists 37 different IDs for it!
I kind of liked QSO for quasars (as it's fairly complete), and PK for planetaries (although PNG is even more complete). But more people will recognize 3C66A and Abell12 than QSO B0219+428 and PK PK198-06.1.
What about M2-9 vs. PK010+18.2? Are Minkowski IDs well-enough known, or might I just as well use the PK ID?
-- Jeff.
For visual amateur use, I think that I would leave out the IRAS (Infra-Red Astronomy Satellite) and 2MASS (2-Micron All Sky Survey) entries, as both refer to catalogs of infrared survey objects (unless a person has "thermal" vision and some big eyes  ). For quasars, the QSO designation would be fairly obvious as it refers to the old "quasi-stellar object" name for these things. The "3C" designation is fairly recognizable, as some rather famous objects (3C 273 for example) were listed with that designation even though it refers to the "3rd Cambridge Catalog of Radio Sources" (really wide eyes ). For planetaries, I like the PK or PNG designations for objects that do not have NGC or IC numbers, but the Minkowski's are a little more obscure in some computerized star atlases. One of my chief early irritations with MEGASTAR is the default use of these lesser-used catalogs for planetary nebula labels rather than staying with some standard like the PK or PNG catalog entries for the first choice designation. Clear skies to you.
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David W. Knisely
Hyde Memorial Observatory
http://www.hydeobservatory.info
Prairie Astronomy Club
http://www.prairieastronomyclub.org
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Jeff Young
Post Laureate
Reged: 08/04/05
Posts: 4122
Loc: Ireland
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Planetary Nebulae
I'm tempted to go back to PK designations for anything that doesn't have an NGC, IC or Abell ('66) designation.
I searched my records and the only PNs that don't currently follow that rule are M1-92 (Minkowski's Footprint) and M2-9 (Minkowski's Butterfly). Since those two bear his name I'll probably leave them with their Minkowski designations (M1-92 isn't in Perek & Kohoutek or PNG anyway).
Quasars, Blazars and other AGNs
I agree that some of the 3C object designations are quite well-known, so I'll leave those. Markarian also seems on-target, and hopefully not too obscure.
I'm tempted to change all my others to QSO designations. The outliers currently are:
APM 08279+5255
PG 1634+706
Zw VII 466
Dang. The Zwicky doesn't have a QSO designiation, and Google turns up 5 times as many references to PG 1634+706 as to QSO 1634+706.
Maybe the only answer is to Google each object that doesn't have one of the more known designations. 
-- Jeff.
--------------------
Nikon 18x70s / UA Millennium Colorado:
Solarscope SF70 / TV Pronto / AP400QMD Coronado SolarMax40 DS / Bogen 055+3130
APM MC1610 / Tak FC-100 / AP1200GTO Tak Mewlon 250 / AP600EGTO
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David Knisely
Postmaster
Reged: 04/19/04
Posts: 8290
Loc: Beatrice, Nebraska
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Jeff Young posted:
Quote:
I searched my records and the only PNs that don't currently follow that rule are M1-92 (Minkowski's Footprint) and M2-9 (Minkowski's Butterfly). Since those two bear his name I'll probably leave them with their Minkowski designations (M1-92 isn't in Perek & Kohoutek or PNG anyway).
Minkowski's Footprint may not have been considered a full planetary nebula (bipolar protoplanetary), so it would probably not have the PK or PNG designation. Clear skies to you.
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David W. Knisely
Hyde Memorial Observatory
http://www.hydeobservatory.info
Prairie Astronomy Club
http://www.prairieastronomyclub.org
Edited by David Knisely (10/20/09 07:09 PM)
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Jeff Young
Post Laureate
Reged: 08/04/05
Posts: 4122
Loc: Ireland
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David --
Interesting; I always thought Minkowski's Butterfly was a bipolar protoplanetary nebula as well, but it seems to be classified as simply a bipolar planetary nebula.
The distinction appears to be whether or not the central star has gotten hot enough to ionize the ejected material -- so if I'm understanding this correctly a protoplanetary nebula is reflective while a planetary nebula is emissive.
My observing reports indicate that I didn't use a filter on Minkowski's Footprint. So far so good. I haven't logged Minkowski's Butterfly, but most reports I've seen indicate that a filter wasn't helpful there either. Hmm....
Ah ha, I found a paper (http://articles.adsabs.harvard.edu//full/1999ASPC..188..241B/0000244.000.html) which indicates that Hubble WF2, WF3 and WFPC2 show that Minkowski's Butterfly is emissive, but mostly in Halpha and NII (where scotopic vision is basically non-existant); the Hbeta and OIII emissions peak at about 30% of the Halpha.
Cheers,
-- Jeff.
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Nikon 18x70s / UA Millennium Colorado:
Solarscope SF70 / TV Pronto / AP400QMD Coronado SolarMax40 DS / Bogen 055+3130
APM MC1610 / Tak FC-100 / AP1200GTO Tak Mewlon 250 / AP600EGTO
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Tony Flanders
Post Laureate
Reged: 05/18/06
Posts: 3469
Loc: Cambridge, MA, USA
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Quote:
At this point I have to confess to being one of those new-generation GoTo guys. I haven't the foggiest idea whether the thin, broom-like one with the bright star in the middle is the eastern or western arc. I just type one NGC ID in, and if it's the wrong one, I try the other one.
Interesting! Most people who are really familiar with the deep sky grew up in the star-hopping era or the mechanical-setting-circles era. Either way, they're used to the sky as shown on an atlas -- or on a planetarium program -- with all the objects forming part of a continuous whole. And either way, they'd think that the natural way to get from the east arc to the west or vice versa would be to move inward toward the focus point of the arc and then beyond to meet the opposite arc.
You're perhaps the first person I've encountered who really knows lots of deep-sky objects, and knows them well, but views them as little island universes with no connection among them. Must be a very different perspective -- a little hard for me to imagine.
--------------------
Tony Flanders
First and foremost observing love: naked eye.
Second, binoculars.
Last but not least, telescopes.
And I sometimes dabble with cameras.
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Jeff Young
Post Laureate
Reged: 08/04/05
Posts: 4122
Loc: Ireland
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Tony --
I keep toying with the idea of getting a Portaball to do some star-hopping. I could also take it to darker sites (something not really possible with my big Mak). But I haven't yet pulled the trigger on that one.
I know my way around many of the constellations from sketching comets with my binoculars, but I only know maybe 20 or 30 binocular deep-sky targets.
Cheers,
-- Jeff.
PS: here's a chance encounter with the Eskimo, which just happened to be in the same binocular field as C/2007 N3 Lulin:
--------------------
Nikon 18x70s / UA Millennium Colorado:
Solarscope SF70 / TV Pronto / AP400QMD Coronado SolarMax40 DS / Bogen 055+3130
APM MC1610 / Tak FC-100 / AP1200GTO Tak Mewlon 250 / AP600EGTO
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Bill Weir
Pooh-Bah
Reged: 06/01/04
Posts: 1299
Loc: Metchosin (Victoria), Canada
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Or, you could just write a bunch of names.
http://rascvic.zenfolio.com/p566114947/h3012fc97#h4d9d1d0
Interestingly enough, when I responded to the thread to which you initially refer, I pointed the OP of that thread towards SIMBAD. SIMBAD gave the MCG designation at the top of the pile. Personally I don't care what designation is given as long as a real catalogue prefix is used. I then at least have a direction of which catalogue to look in. Common names are fine, as long as they are not the sole moniker.
I deal with this problem daily in the field of medicine. There are way too many brand names for medications when they are using the exact same chemical. Each company uses a different inert base then calls the drug something new. Then they decide to market it to a different audience and repackage it again with a different coloured capsule and call it something new again. Same company, same drug, two target audiences so two different names. There should be a law.
Bill
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6'' Orion SkyQuest
12.5'' f/5 Custom Truss Dob
William Optics 80mm ZenithStar ED II
f/5 25" newtonian on a giant GEM, any time I want
Observing sessions grand total for 2008, 121.
So far in 2009, 92
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David Knisely
Postmaster
Reged: 04/19/04
Posts: 8290
Loc: Beatrice, Nebraska
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Quote:
David --
Interesting; I always thought Minkowski's Butterfly was a bipolar protoplanetary nebula as well, but it seems to be classified as simply a bipolar planetary nebula.
The distinction appears to be whether or not the central star has gotten hot enough to ionize the ejected material -- so if I'm understanding this correctly a protoplanetary nebula is reflective while a planetary nebula is emissive.
My observing reports indicate that I didn't use a filter on Minkowski's Footprint. So far so good. I haven't logged Minkowski's Butterfly, but most reports I've seen indicate that a filter wasn't helpful there either. Hmm....
Ah ha, I found a paper (http://articles.adsabs.harvard.edu//full/1999ASPC..188..241B/0000244.000.html) which indicates that Hubble WF2, WF3 and WFPC2 show that Minkowski's Butterfly is emissive, but mostly in Halpha and NII (where scotopic vision is basically non-existant); the Hbeta and OIII emissions peak at about 30% of the Halpha.
Cheers,
-- Jeff.
The research on the Footprint (Mink 1-92) that I have read indicated that the central star is still fairly bright and is also illuminating gas and dust (a continuum reflection) rather than only exciting it with strong UV light to glow in the OIII lines as is seen with most true planetaries. I found that the only filter which seemed to help the Footprint much was a broadband one (Lumicon Deep-sky), so there must be a lot of continuum light from it. Thus, the nebula may be merely on its way to eventually becoming a planetary, although the bipolar feature is also seen in some other types of diffuse reflection nebulae. One "bipolar" one I like to look at is CED 62 (NGC 2163) in Orion, as it is like a giant but fainter version of the footprint. Clear skies to you.
--------------------
David W. Knisely
Hyde Memorial Observatory
http://www.hydeobservatory.info
Prairie Astronomy Club
http://www.prairieastronomyclub.org
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Jeff Young
Post Laureate
Reged: 08/04/05
Posts: 4122
Loc: Ireland
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Quote:
Or, you could just write a bunch of names. http://rascvic.zenfolio.com/p566114947/h3012fc97#h4d9d1d0
Bill --
Yes, I intend to do that more with my sketches.
(I guess I was mostly motivated by the underlying question of what ID to use as the primary key in the database I store my observations in. While I can search/sort on other keys, it's much easier on the primary.)
Quote:
One "bipolar" one I like to look at is CED 62 (NGC 2163) in Orion, as it is like a giant but fainter version of the footprint.
David --
Cool; I don't have that one on any of my lists.
Cheers,
-- Jeff.
--------------------
Nikon 18x70s / UA Millennium Colorado:
Solarscope SF70 / TV Pronto / AP400QMD Coronado SolarMax40 DS / Bogen 055+3130
APM MC1610 / Tak FC-100 / AP1200GTO Tak Mewlon 250 / AP600EGTO
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PeterSurma
super member
Reged: 08/24/06
Posts: 122
Loc: Heidelberg, Germany
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Actually, I recently thought about the same problem, as I was figuring out how to merge object catalogs based on object IDs. Of course it's silly to have both an entry for M31 and NGC224 :-). The way to solve this is precedence conventions along the same line that you have discribed in your initial post.
On the other hand I now tend to give several names in my oblists, because different people sure have different focus (e.g. Arp vs. NGC) - like this:
http://eyes4skies.de/Internet/Astro/CrossRef/Crossref.htm
People created different cats with different focus, and it's not helpful to show no arp number to people who are just now running a project on arps... (although I do not put a lot of effort in finding those crossrefs)
I find DSB pretty helpful. It gives you a lot of alias names:
http://messier45.com/cgi-bin/dsdb/dsb.pl?ss=120908595465365&str=M+31
For QSOs I tend to use Q numbers, all others drive me crazy... :-) By the way, there is also a 4C catalogue !
http://en.wikipedia.org/wiki/Fourth_Cambridge_Survey
--------------------
Peter
Web: http://www.eyes4skies.de/home_EnglishVersion.htm
Scopes: From 3inch photographic APO to 20inch f/4 Dob
Edited by PeterSurma (10/22/09 03:20 PM)
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