A Complete Messier Catalogue?

[glenc]

How many objects would there be in the Messier Catalogue if Messier had observed from both the northern and southern hemisphere instead of just observing from Paris? How many Messier objects would there be if he had seen every deep-sky object that it was possible to see using his telescopes? I used Steinicke’s NGC and IC catalogues to try and estimate an answer. However Steinicke’s catalogue does not of course include non-NGC and non-IC objects so my count is a conservative estimate. First I found the faintest Messier objects according to Steinicke’s catalogue. These were: 1. The faintest open cluster (OC) is M26 which is magnitude 8.0. 2. The faintest globular cluster (GC) is M72 which is magnitude 9.2. 3. The faintest planetary nebula (PN) is M76 which is magnitude 10.1 and 4. The faintest galaxies (Gal) are M91 and M98 which are both magnitude 10.1. 5. Most nebulae (Neb) have no magnitudes but the faintest five in Messier’s catalogue are M1, M16, M20, M43 and M78. Then I used the above magnitude limits to come up with A Complete Messier Catalogue. It is not the final Complete Messier Catalogue, just one attempt. Some of the included nebula may be too faint for Messier to see. My list contains a large number of open clusters and I was tempted to use the second faintest OC (magnitude 7.4) as my OC magnitude limit, but decided to use magnitude 8.0. The columns are: Cat Num, catalogue number Type and sub-type CON, constellation. Vmag SB, visual magnitude and surface brightness. Length and Width RA 2k min sec, Right Ascension 2000 declin m s, declination 2000. 10pm, southern season at 10pm. (11pm DST) This method gave 176 OC, 146 Gal, 81 GC, 29 Neb and 25 PN in A Complete Messier Catalogue. That is a total of 457 clusters, nebulae and galaxies and 111 of these are summer objects. The tab-delimited file below can be copied to MS Excel then filtered and sorted. The user can then delete objects that are too far north (or south) to see. Reference http://www.ngcic.org/steinicke/2006/explan.htm

[DobDobDob]

Hi again, I can see you are a Messier buff, have you given any thought in breaking the list down into observable by binocular as opposed to telescope?

At this point I have only just purchased my binoculars and have only had one decent night to observe with a tripod, so outside of M42 which has a special significance for me, I am at the starting line ready to go Messier hunting, but I would prefer to have a set assignment and one that is possible and roughly equal to my inexperience.

Your thoughts?

[jjjnettie]

Here's a list for you Tailwag.
It's from the Southern Sky Binocular Club.

http://www.astroleague.org/al/obsclubs/sskybino/ssbinoc2.html

And of course not forgetting The Ultimate Messier Object Log, TUMOL, that list all the Messier objects by binocular difficulty.
http://www.davidpaulgreen.com/tumol.html

[DobDobDob]

Thanks jjjnettie but I have both those URL's, my point is there is nothing specifically for Australia, I have via another thread written to the moderators suggesting an IIS awards system for Messier hunting, and for that matter other DSO's as well. :)

[glenc]

It depends on the size of your binoculars. My 20x80s will show nearly all of the objects in this list. The small PN will be stellar however.

[DobDobDob]

Great to hear that, I have 20x80 triple lens from Andrews and so far, what I have seen (one night only) has been stunning, it will be much better actually observing with a mission in mind as opposed to just wandering over the sky randomly. :D

[glenc]

I suggest you start with the summer GC and Gal brighter than mag 9 and also try the summer OC brighter than mag 6. Do you have a dark site to observe from?

[glenc]

Here is a list of 600 objects that are ranked by magnitude. Try looking at those with rank less than 10.
http://www.iceinspace.com.au/forum/showthread.php?t=12801&highlight=ranked

[DobDobDob]

Hi glenc,

The Silicon Owl site is awesome, this direct link has the database in night vision mode, I appreciate you directing me to it.

http://www.siowl.com/scripts/ObsDatabaseRed.php

As for a dark site, I will be hooking up with my old astronomy club (WSSAG) which has a dark site in the Blue Mountains, however mostly I will be observing from home, weather permitting and its not too bad where I am.