when to refer to objects based on Messier, NGC etc

[troypiggo]

As a beginner, I'm still coming to terms with names and catalogues. I'm at the stage where a common name for an object like "Witch Head Nebula" or "Horsehead Nebula" means much more to me than their Messier or NGC numbers. I am learning, though.

So when I visit the deep space image forum here, many titles of posts are just "M81" or "NGC2021" etc. It doesn't mean that much to me until I see the image. I realise many here do know what it will be an image of, and I'm sure I'll get there.

I think when I do start posting images, I'll try to use the catalogue numbers as well as common names (if available) in the title to cover all bases. But there are so many catalogues, and some refer to the same object.

So if an object has a Messier no and an NGC no, I'd probably assume the Messier no would be preferable since it's a smaller and older(?) or more common catalogue? Then I'd probably refer to the NGC number if there was no Messier for it. If no NGC, I'd use what? I'd assume that anything I'd be able to image with my current and near-future gear will be covered at the very least in the NGC catalogue?

Sorry if these are pedantic and silly questions, just trying to get a feel for order of preference from the experienced astro-community.

[jjjnettie]

When you first start off, you probably be imaging the brighter objects of the Messier and NGC catalogues anyway so it won't take long to associate the numbers with the object and it's common name.

[Kevnool]

Then you can look up the IC catalogue during and after your hunt around the messiers and the NGC objects.....cheers Kev.

[renormalised]

Plus, if it's stars you're imaging, apart from the more common names that everyone knows, you also have SAO numbers, Flamsteed numbers (F), Henry Draper and Henry Draper Extended (HD and HDE), AAVSO Variable Star Names (A-Z, AA-ZZ etc), Gliese (GL), Bonner Durchmusterung (BD), Bayer designations, Hipparcos numbers (Hip), Tycho numbers (Tyc) and a raft of others.

You also have, for galaxies, the UGC numbers (Uppsala Galaxy Catalogue), ESO catalogue of extragalactic objects (ESO), Harp Catalogue of Peculiar Galaxies (Harp) and about a million different others. Not to mention...PKS, Dunlop (D), Caldwell (C), 2MASS, IRAS...any major observatory or institution has released a catalogue of one sort or another. I've even made one up myself....catalogued all the stars in both the Nth and Sth hemispheres from -70 to +70, down to mag 3.5. Had their common names (if the had one), Bayer designation and SAO/HD numbers, temps, B-V indices, distances, RA and DEC co-ords, spectral classes etc. Setup a database you could query for each star or a group of stars based on whatever criteria you chose....did this all for an assignment for uni. Got pretty good marks if I may so:)

Really, there's so many catalogues, you can lose track of them very easily. I'd just stick to the more common ones and keep the others in mind...if you should ever come across them being used.

[glenc]

I suggest M, if available, then NGC then IC then the name given by the person who found the object.
I object to Caldwell renaming objects that already have names.
Here are some common names: http://messier.obspm.fr/xtra/supp/d-names.html

[troypiggo]

Thanks very much for your input all.