Answer to Question #54961 in Astronomy | Astrophysics for Lia

Question

At 6300 ˚A (630 nm) the flux from a source is 10−18 W m−2 ˚A−1. Determine the photon rate passing through a telescope aperture with D = 2·2 m over a wavelength interval of 100 A˚ . Calculate the best possible S/N ratio of a measurement with an integration time of 30 s.