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[Rocketman]

I'm wanting to get an idea of how much magnification is needed to observe a given magnitude. I know of some satellites that have a magnitude of 8.5, and they make slow passes, so they should be viewable with the correct magnification. Is there a formula for figuring this?

[starbux]

With light polluted skies increasing magnification will make fainter stars easier to detect, but only to a certain point. Aperture still rules in matters such as this.

I don't myself have a formula for you, but I do remember reading this article on "Cloudy Nights" It may offer some gleaning/insight that you can use:
Which Binoculars will give you maximum Star Counts?

While the article deals with star counts and fov, there is mention of magnification and fainter stars (as a result of smaller exit pupil). The article assumes a dark sky. You may have to modify the magnetudes listed based on your naked-eye limits. Hope this helped.

[starbux]

Actually, the article contained the relevant formula which I quote:

Larger exit pupils and lower magnifications are not as efficient in pulling fainter stars out of the background. Magnitude limits for optical systems peak with magnifications that provide a 1 mm exit pupil.

This would equate to approximately 25x per inch of aperture. It’s likely that the magnitude threshold for binoculars operating at low magnification is somewhat lower. I went with the traditional magnitude limit formula: Mag = 2.7 + 5 log D (D being objective size in millimeters).

Using logrythms probably isn't necessary. The 25x/inch or 1mm exit pupil is what you want to go for maximizing your faint star perception. You could try higher than that in your light-polluted sky, but in any case your scope will still be limited in theory by its aperture as far as how faint can you go. Which magnifications "reveal" fainter stars over the preceeding (lower) magnification is probably highly subjective. Experimenting with star fields plotted on one of the more comprehensive star atlases such as Uranometria 2000 (to mag 9.5) or a desktop using Tycho star catalogue (to mag 12+) may be your best bet.

[Chicago Astronomer - Astro Joe]

Stars...where the hell you get stars in a big city like Chicago? I have read about such creatures mulling about the heavens...blinking and winking.

Hope to see one soon!