Ratio of signal to noise (using eqs. [13] and [14]) expected for a NS surface mode during a 10 s X‐ray burst. We set ﹩k_{\mathrm{B}\,}T_{c}=3﹩ keV, ﹩D=4.3﹩ kpc, and ﹩\Delta T/ T_{c}=0.025﹩, and compare a flat energy response (solid line), the ﹩A_{\mathrm{eff}\,}( E) ﹩ of one PCU on RXTE’s PCA (dotted line), and the proposed ﹩A_{\mathrm{eff}\,}﹩ for the NuSTAR mission (dashed line). Each curve connects a series of points, with each point representing an integration over a 3 keV width energy bin.