David, This doesn't answer your original question, but I wanted to share an excellent resource from Japanese astronomer Seiichi Yoshida: http://www.aerith.net/comet/future-n.html The details for each comet have predicted magnitude plotted over time, and his weekly information summarizes observing expectations. Good stuff. Adam > From: dmdouglass@xxxxxxxxxxxxxxx > To: az-observing@xxxxxxxxxxxxx > Subject: [AZ-Observing] Re: When can we expect to "SEE" Comet ISON > Date: Fri, 25 Jan 2013 10:47:51 -0700 > > Limiting Magnitude is the term that was eluding me. > Thank you to all that responded so far. > Googling "Limiting Magnitude" produced several sub-sections, one of which > was "Charts". > > There, I found links to Weasner.com (Mr. Meade ETX) > As well as links to the Arkansas Sky Observatory (Dr. Clay [Sherrod].. aka > Mr. Meade knowledgebase) > And also a link to an online "Telescope Limiting Magnitude Calculator" > http://www.cruxis.com/scope/limitingmagnitude.htm > There was commonality within most articles, and the problem of variables was > also commonly discussed. > > I played with the calculator for awhile. I have an SQM meter, and am > familiar with the return values for different conditions for various sites. > For my "backyard" conditions, my situation seems to return a value of > 13(ish), and if I use dark sky locations, upwards of 15. > And that is what my experience has shown, as I stated earlier, with > reference to galaxies (mostly 11-12). > > David M. Douglass > dmdouglass@xxxxxxxxxxxxxxx (secondary) > david@xxxxxxxxxxxxxxx (main) > Cell (602) 908-9092 > > > -- > See message header for info on list archives or unsubscribing, and please > send personal replies to the author, not the list. > -- See message header for info on list archives or unsubscribing, and please send personal replies to the author, not the list.