Re/OsConstraint on the Time Variability of the Fine-Structure Constant

We argue that the accuracy by which the isochron parameters of the decay ${}^{187}\mathrm{R}\mathrm{e}\to {}^{187}\mathrm{O}\mathrm{s}$ are determined by dating iron meteorites may constrain the possible time dependence of the decay rate and hence of the fine-structure constant $\alpha$, not directly but only in a model-dependent manner. From this point of view, some of the attempts to analyze the Oklo constraint and the results of the quasistellar-object absorption lines are reexamined.