  We propose a new method to search for light (pseudo-)scalar particles in the
spectra of compact astrophysical objects such as magnetars, pulsars, and
quasars. On accounts of compact astrophysical objects having intense magnetic
fields extending over large volumes, they provide good conditions for efficient
photon-particle oscillations via the Primakoff process. In particular, we show
that if the coupling constant for light (<1e-2 eV) axions, g>1e-13 [1/GeV] then
it is likely that absorption-like features would be detectable in the spectrum
of compact astrophysical sources.
