It's not electrolytic or tantalum, as there is no "+" sign indicating polarity, as with C2 and C3. So ceramic, mylar, etc., this should be a relatively non-critical part. And Tim is right, 0.047µF should be just fine.
0.05µF was once a common value (back in the days when Pluto was a planet) but most seem to have gone to the E12 preferred numbers or whatever, hence 0.047.