A low-mass boson a, if it couples by a two-photon vertex, can be produced in the plasma decay process ${\ensuremath{\gamma}}_{t}$\ensuremath{\rightarrow}${\ensuremath{\gamma}}_{l}$+a and in the plasma coalescence process ${\ensuremath{\gamma}}_{t}$+${\ensuremath{\gamma}}_{l}$\ensuremath{\rightarrow}a, where ${\ensuremath{\gamma}}_{t}$ and ${\ensuremath{\gamma}}_{l}$ are transverse and longitudinal plasmons, respectively. The previously discussed ${\ensuremath{\gamma}}_{t}$\ensuremath{\rightarrow}${\ensuremath{\gamma}}_{t}$+a is kinematically suppressed. It is shown that a previous calculation of the Primakoff emission rate already includes these effects if T\ensuremath{\gg}${\ensuremath{\omega}}_{0}$ (plasma frequency ${\ensuremath{\omega}}_{0}$) so that astrophysical bounds on the axion-photon coupling remain unchanged.