User talk:Jim Cornmell

Herschel 400 Catalogue

Thank you for your comments on my talk page. I look forward to cooporating with you in the future.

I really like the work that you are doing with the Herschel 400 Catalogue, and I'm hoping that you will also work on the Caldwell objects. I think it is great to gather all of this deep-sky amateur astronomy information onto Wikipedia. My amateur astronomy resources are limited, so I am not able to write as much on many of these amateur-related topics. (However, I do have ample professional astronomy resources.)

You may be interested in looking at Wikipedia:WikiProject Astronomical objects. This is a good forum with many level-headed people who are trying to improve many of the astronomy articles on Wikipedia.

On the name edits, you can see my comments in the talk sections of both the WikiProject and Herschel 400 Catalogue pages. Basically, a couple of previous Wikipedia users started adding invented nicknames to the Wikipedia website. The problem with this approach was that it could easily generate confusion, especially if the new nickname was not widely recognized. Two good examples are the "Phantom Galaxy" and the "Fried Egg Galaxy".

The former Wikipedia user HurricaneDevon (a good example of a person whose mistakes you do not want to repeat) either created the name "Phantom Galaxy" for M74 or copied it from elsewhere in Wikipedia without investigating its origins. The problem with this is that professional astronomers occasionally identify other objects as "phantom galaxies". Identifying M74 as the Phantom Galaxy would simply confuse people and lessen Wikipedia's ability to serve as a useful reference.

The Fried Egg Galaxy is another good example. Two different external websites name either NGC 7742 or M83 as the "Fried Egg Galaxy". Identifying one or the other object as the Fried Egg Galaxy would cause confusion for people who had been told that it was the other galaxy. While Wikipedia is a good place for dissemenating information, it is not the place on making choices on naming conventions (such as official nicknames for galaxies). In fact, to do so would damage Wikipedia's credibility as a usable information source.

As you have already stated, some of the nicknames that you have used are indeed used elsewhere on the internet. However, it could be either an individual's invented name for an object (such as HurricaneDevon's "Surfboard Galaxy") or simply a description that is incorrectly interpreted as an official nickname. Also note that many websites copy Wikipedia. It may seem like the name "Surfboard Galaxy" is widely accepted, but that is only because an individual (HurricaneDevon) put the name on Wikipedia and many other websites then copied Wikipedia. The O'Meara book is OK; please reference it if you use its nicknames (which you probably only need to do in the Wikipedia articles on the individual objects). Finally, as to names heard word-of-mouth at star parties, I would not trust such names. Every amateur astronomy group may have different nicknames for objects invented by individual members. For all you know, an amateur group in Hawaii may refer to M81 as the "Toilet Bowl Galaxy".

Now, to choose good nicknames, I recommend looking at either http://simbad.u-strasbg.fr/sim-fid.pl SIMBAD] or NED. Both these websites are used by professional astronomers for astronomical information, including object names and nicknames. I would recommend checking both websites for potential nicknames. If neither one lists the nickname, it probably is not widely used. Also, check to see if the nickname appears on APOD. If it does, then it is probably safe to use (although if it is not in either SIMBAD or NED, it may be uncommon). Do not trust the nicknames on the SEDS.org website. SEDS is only an amateur astronomy organization and is not in the position to create official astronomical nicknames. (It does not even look like SEDS is polling its members to see if they agree with their "nicknames".)

As to the identity of M102, try doing a search in both SIMBAD and NED on the name. One of the websites identifies M102 as M101, while the other identifies it as NGC 5866. I have a book published in 1991 by K. G. Jones that claims that the identity is still undetermined. However, all of that information could be out-of-date. I am unfamiliar with the Hogg article, so I am not certain as to whether its information is better or worse than Jones's information. If you want, you can rewrite the M102 article to discuss the object's identification (although you should ignore the "merge articles" notice at the top of the page, which has been there for weeks). Please include references so that we know that you did not make up the information.

I hope this has not been too overbearing. I really hope that you continue to work on amateur astronomy Wikipedia articles, because they really could use some work.

Thank you, George J. Bendo 09:55, 24 August 2006 (UTC)

All makes sense. When I get time I will update the M101/M102/NGC5866 articles. Probably base some of the information on K. G. Jones and Stephen James O'Meara's books, both indicate M102 is a mistaken duplicate of M101. Also when I get a chance I will edit the Caldwell page to be of a similar style to the H400. I will add references (my lack of experience on wiki). Finally I will keep in mind the notes on names, and use SIMBAD/NED, although I think Stephen James O'Meara has fallen foul of your notes, many of the names are in his Caldwell and Messier books! -- Thanks, Jim Cornmell 10:33, 24 August 2006 (UTC)

Caldwell Catalogue Review

Here are my general comments on the Caldwell catalogue. This is a commentary style that I normally use when reviewing professional astronomy papers, so it may seem very critical.

Overall, the article could use significant revision, although it presents some good general reference material for amateur astronomers as well as some in-depth information on the topic. The article should be revised with emphasis on introducing less-knowledgable readers to the subject and presenting the technical information (the map and the list) in an easy-to-read manner.

1. The introduction (the part that appears before the "Contents" box) should really emphasize the purpose of the Caldwell Catalogue: to give amateur astronomers a list of deep-sky objects that are as interesting and beautiful as the objects in the Messier Catalog. It should also explain the criteria used to choose objects for the Caldwell Catalogue. As this is currently written, readers will not understand what the Caldwell Catalogue was created for.

2. The Vital Statistics section could be rewritten in full sentence form rather than in bullets. This should be part of the introduction at the top of the page. The similarities to the Herschel 400 Catalogue (especially the motivations for creating the separate catalogs) should be emphasized.

3. The "Errors within the catalogue" section seems overly melodramatic. The problems with arranging the objects by declination and the problems with C37 do not seem serious. The only serious problems are C49, C89, and C100. The history behind the incorrect identification of some objects and the reasons why these objects were incorrectly identified could be explained in the article. It is also unclear as to how some objects were incorrectly identified. For example, was C 49 originally listed as "Rosetta Nebula (NGC 2237-2239)" or was it listed as "NGC 2337-2339"? The article is unclear. I also recommend putting this in a larger introduction section.

4. The "Distribution of Caldwell objects" map is a good idea, and a similar chart should be created for the Messier objects if one does not already exist. However, the symbols in the map of the "Distribution of Caldwell Objects" are too small. It is hard to pick out the sources. This is particularly needed in you want to demonstrate to readers where the objects are distributed in the sky.

5. The "Caldwell objects which are also Herschel 400 objects" probably is not needed. This could be folded into a discussion in the introduction (see comment 2).

6. The "Number of objects by type in the Caldwell catalogue" is a good list to have with any type of compilation like this one.

7. I do not understand why you have an interest in giving the number of objects per constellation. As both a professional and an amatuer astronomer, I would not be interested in such a break down for such a mixture of objects. It is scientifically interesting when discussing, for example, the distribution of one type of object, such as globular clusters (which should be found mostly near Sagittarius) or galaxies (which should be grouped into a few prominent places such as Virgo and Coma Bernices). In this case, however, all the objects are lumped together. Knowing their distribution according to constellation is not that interesting. I would not include the chart. (Such a chart would be interesting for the Messier list, but only because of that catalog's historical significance.)

8. You should consider formatting the actual list of objects the same way as the list of Messier objects. The Messier object list gives very useful information in multiple forms. For NGC 5005, for example, it would be much more useful and interesting to have an entry that said "C29, NGC 5005, Spiral Galaxy, Canes Venatici, magnitude=10.6". (This would be a good idea with the Herschel 400, although it would take a lot of time to finish such a project.)

9. Be careful with the made-up names. "Pincushion Cluster" is not a real name according to SIMBAD. (Is that an O'Meara name?)

10. The "Criticism of the Caldwell Catalogue" section (and the reference for the information) seems overly melodramatic. It is probably a valid criticism, but it could be toned down. Again, this type of information could be folded into an extended introduction.

11. The links to the categories in the "See also" section may not be necessary. Otherwise, this is a good list of "See also" links. The "External links" section is also good, although the link to www.ngc891.com could be labeled better.

12. The grammar needs to be improved in a few places, but this is a minor detail.

I hope this criticism is not too harsh. (I deal with this kind of thing all the time in my job.) I do think, however, that this article could be quite outstanding with a bit more work. George J. Bendo 18:56, 31 August 2006 (UTC)

Thanks for the comments, all valid and interesting. I think I was keen to get something out there for comment and then improve it over the next few weeks (especially considering the contents of the original article), I prefer getting something started and evolved over time rather than spending forever on something only to find it needs a complete rewrite. I'll tinker on the Caldwell one over the coming weeks with your comments in mind. -- Jim Cornmell 09:55, 1 September 2006 (UTC)

I am glad that you found my comments useful. I definitely agree that the current version of the article is vastly improved over the previous version. George J. Bendo 14:04, 1 September 2006 (UTC)

Created Images

• SVG Caldwell Star Chart Caldwell Star Chart in SVG format
• PNG Caldwell Star Chart Caldwell Star Chart in PNG format

Two questions.

1. I wish to upload the SVG file as a compressed SVG file to save space improve downloads etc, i.e. an svgz, I tried this but received a warning, and no images.
2. I wish to remove this PNG image as the SVG file has supercede it. How do I remove an image I have uploaded?

Unfortunately, I don't have too much experience with the SVG format -- it's wonderful, and I really should learn it at some point. Possibly .svgz isn't a supported file format; if you haven't already, you might try uploading the uncompressed .svg and see if that works. To your second question, you can add {{SupersededSVG|newimage.svg}} to the image description page of the old image (see an example here). Hope that helps. :) Luna Santin 12:03, 4 September 2006 (UTC)

I've added {{SupersededSVG|CaldwellStarChart.svg}} to the image page and do not get what I expected. What am I doing wrong?

I think that the problem is that the template simply does not exist here on Wikipedia - I've only seen it on Commons. You could copy the template over here if you really need it. —Daniel (‽) 14:24, 4 September 2006 (UTC)

Thanks that worked -- Jim Cornmell 15:07, 4 September 2006 (UTC)

Caldwell Catalogue Second Review

I have been busy with work writing a proposal for the Submillimeter Array, so I have not had time to review the Caldwell Catalogue article until now. It generally looks much improved over the previous version, and it really looks like a viable reference for the internet (which it automatically becomes because of the tendency for Wikipedia articles to appear high on Google searches). My comments are as follows:

• The introduction has strongly improved, but it still lacks key information on the importance of this catalog. You need to strongly state why other people should even care about the catalog. Otherwise it is simply a list of stuff in the sky.

Will think of suitable changes.

• The textual information presented in the article is now more formal, which is much better. Some of the criticism from the Alister Ling article can still be included (such as the fact that Caldwell named the catalog after himself), but they should be written more dispassionately (with less emotion and more objectivity) than in the Ling article.

Will think of suitable changes.

• The star chart is much better. On one of the monitors that I use (a 17" 1280x1024 monitor), the figure looks great. On the other (a 17" widescreen 1920x1200), the symbols look a little small, but many other things also look small. I rather like this figure because it can be used to teach science (such as demonstrating how clusters and nebulae lie in the plane of the galaxy and how galaxies may cluster).

Great I've generated on a similar chart for Messier Catalogue and am working on one for Herschel 400 Catalogue, Herschel is more problamatic as I'm trying to ensure the labels do not crash into one another. As an aside these are all SVG documents so are vector, i.e. scale well. I was originally thinking they should be PNG but if people want to print them on A3 or A4 then the quality should be excellent, also not dependant on the dpi of the printer.

• I still am disinterested in grouping the Caldwell objects by constellation. It does not seem to convey any important information.

OK removed.

• The list of Caldwell Objects is much more useful, and it could serve as a great reference for amateur astronomers. All of the provided information is very practical and useful. I only have one format problem and one content problem.

• • The format problem is with the colors of the bars representing nebulae. On one of my computers, the red links are hard to read against the red background. If the colors of the background were made a lighter shade of red, this would be better.

Yea I'm not overly keen on the colours, I used the same format (now on Herschel 400 Catalogue also) as the Messier list, for consistency and incase there was a reason for this. My preference would be to remove the colours totally, also remove the object type text, and just have the object symbol, as in the star charts (as used in Tirion star atlas). And change the key accordingly.

I like colors in general myself, although colors do not work so well in the Herschel 400 list because it is too long. You could try tweaking the colors to improve their readability.

• • My content issue is with the distances. For most things in the Milky Way, distances are easy to measure. For galaxies, however, distances can be difficult to measure (despite what you may have learned about the Hubble law). When you quote distances, you may want to reference them. Use good scientific references from professional journals; the SEDS website and popular astronomy books usually contain inaccurate distances. (To see how I use references, please look at the NGC 4594 page.)

All from pages within Wikipedia. From what you are saying its best to just miss out the column totally, should therefore be removed from the Messier page.

I think Wikipedia has a warning that says, "Do not reference Wikipedia." A lot of people have put a lot of garbage up on Wikipedia, and it could take an even longer time to clear it all out. (However, that does not mean that you cannot follow up on references within Wikipedia pages. I do this in professional articles.)

I am in favor of keeping distances in the Messier and Caldwell lists just because those lists are shorter and easier to update. I do not think that removing distances wholesale is necessary.

That is all I have to say on the article. You may also be interested in participating in the discussions at Wikipedia talk:WikiProject Astronomical objects, which is another place where you can ask people to review articles. George J. Bendo 11:09, 6 September 2006 (UTC)

Just posted questions there, thanks. -- Jim Cornmell 12:37, 6 September 2006 (UTC)

Would it be OK if I tried editing the introduction to the Caldwell Catalogue page? George J. Bendo 13:43, 6 September 2006 (UTC)

No worries go ahead -- Jim Cornmell 14:35, 6 September 2006 (UTC)

Rewrote introduction to Caldwell Catalogue

I rewrote the introduction to the Caldwell Catalogue. I think you had most of the information that you needed in place in the list, but it just needed to be organized better. One comment: two of the "anomalies" in the list's compilation do not appear to be errors. According to SIMBAD, NGC 6885 is not the same object as NGC 6882, and the designations for the Rosette Nebula looked very reasonable. (Did this information on the anomalies come from the O'Meara's book? I'm beginning to think that his books contain a lot of "anomalies".) George J. Bendo 10:50, 8 September 2006 (UTC)

I've checked around and the book seems correct. See [www.ngcic.org], in particular the pages on NGC6882 and NGC6885, [1]. To be honest though I'm not that fussed. I think we could just word it as a possible duplication in the NGC and reference the discrepancies in SIMBAD and NGCIC.org. The text in O'Meara basically discusses the fact different sources name this patch of sky differently, which just leads to confusion about the ID. In the book he cites several sources which label it as 6885 and several that cite it as 6882, I'll add the citations when your finished. I think your right about the Rosette Nebula the fact is there are a string of NGC id's for the different parts and some users just quote some of them is neither here nor there. --Jim Cornmell 15:56, 8 September 2006 (UTC)

I did a search on NGC 6882 at the ADS Abstract Service and found that most scientific papers list it as "NGC 6882/6885" or something similar. I still would not call this a compilation anomaly or error if it was originally labeled as "NGC 6882" by Moore. I would, however, recommend attaching a note to the entry for NGC 6882 in the source list. George J. Bendo 16:19, 12 September 2006 (UTC)

Your charts

As wiki does not support xlink the result of clicking on your maps is a parser error. Maybe you could filter-out xlink from svg files. Or maybe there's a different cause for this error. I’ve tried clicakable maps in SVG 6 month ago and had to resign myself to the poor level of support for SVG on wiki. Please let me know if you find otherwise; I have potentially scores of clickable charts in TNO and irregular satellite area.

XML Parsing Error: prefix not bound to a namespace
Location: http://upload.wikimedia.org/wikipedia/en/e/e2/MessierStarChart.svg
Line Number 1097, Column 1:
<use xlink:href="#oc" x="935.3" y="81.4"/><text x="907.3" y="83.4" class="obj">103</text>

. Regards Eurocommuter 10:41, 10 September 2006 (UTC).

Thanks will check. Also noted that firefox 1.5+ struggles with my charts, I'm planning on filtering through Illustrator CS2, should sort out everything. As an asside have you managed to get svgz (compressed SVG) files working on wiki? --Jim Cornmell 07:42, 11 September 2006 (UTC)

Yes you’re right. IE is not so pedantic (I'm using Firefox; IE is fine). I remember vaguely that I added explicit xlink namespace to the svg element

xmlns:xlink="http://www.w3.org/1999/xlink"

. You could check if you have one. And no, I never tried zipped svg. Eurocommuter 17:13, 12 September 2006 (UTC)