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Limiting Magnitudes

Figure 8 plots the log(Exposure time (secs)) needed to reach a given

Figure 8: Calculated exposure times for various conditions.

magnitude at a S/N of 5 and 20, for seeing conditions of 0.564''\ (ie 1 tex2html_wrap1403 '', ie for surface brightness), 0.8'' and 1.2'', and for apertures of radius 2.5 tex2html_wrap_inline1163 seeing, observing in ND_STARE mode.

Shaun Hughes
Thu Mar 14 14:48:38 GMT 1996