Electromagnetic dissociation of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mi mathvariant="normal">B</mml:mi><mml:mprescripts/><mml:none/><mml:mn>8</mml:mn></mml:mmultiscripts></mml:mrow></mml:math>and the astrophysical<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>S</mml:mi></mml:mrow></mml:math>factor for<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mi mathvariant="normal">Be</mml:mi><mml:mprescripts/><mml:none/><mml:mn>7</mml:mn></mml:mmultiscripts><mml:msup><mml:mrow><mml:mo>(</mml:mo><mml:mrow><mml:mi>p</mml:mi><mml:mo>,</mml:mo><mml:mi>γ</mml:mi></mml:mrow><mml:mo>)</mml:mo></mml:mrow><mml:mn>8</mml:mn></mml:msup><mml:mi mathvariant="normal">B</mml:mi></mml:mrow></mml:math>

We present $S$ factor data obtained from the Coulomb dissociation of $83\phantom{\rule{0.3em}{0ex}}\text{MeV}∕\text{nucleon}$ $^{8}\mathrm{B}$, and analyze $^{7}\mathrm{Be}$ longitudinal momentum distributions measured at 44 and $81\phantom{\rule{0.3em}{0ex}}\text{MeV}∕\text{nucleon}$ using a potential model, first-order perturbation theory, and dynamical solution of the time-dependent Schr\"odinger equation. Comparing our results with independent continuum-discretized coupled channels calculations, we study the reaction model and beam energy dependence of the $E2$ contribution to the dissociation cross section. By fitting radiative capture and Coulomb breakup data taken below relative energies of $400\phantom{\rule{0.3em}{0ex}}\text{keV}$ with potential models constrained by $^{7}\mathrm{Li}+n$ and $^{7}\mathrm{Be}+p$ elastic scattering data, we examine the mutual consistency of recent ${\mathit{S}}_{17}$ measurements and obtain a recommended value for ${S}_{17}(0)$ of $18.6\ifmmode\pm\else\textpm\fi{}0.4$ (experimental) $\ifmmode\pm\else\textpm\fi{}1.1$ (extrapolation) eV b $(1\ensuremath{\sigma})$. This result is in good agreement with recent experimental determinations of the asymptotic normalization coefficient of the valence proton wave function in $^{8}\mathrm{B}$.

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