  A previously published analytical magnetohydrodynamic model for the local
interstellar magnetic field in the vicinity of the heliopause (R\"oken et al.
2015) is extended from incompressible to compressible, yet predominantly
subsonic flow, considering both isothermal and adiabatic equations of state.
Exact expressions and suitable approximations for the density and the flow
velocity are derived and discussed. In addition to the stationary induction
equation, these expressions also satisfy the momentum balance equation along
stream lines. The practical usefulness of the corresponding, still exact
analytical magnetic field solution is assessed by comparing it quantitatively
to results from a fully self-consistent magnetohydrodynamic simulation of the
interstellar magnetic field draping around the heliopause.
