I am studying astronomical imaging, and am curious about how to image astronomical objects which are coherent. Stellar interferometry measures the mutual coherence function of a star, and then uses the Van Cittert-Zernike theorem to retrieve the spatial distribution of the star by a Fourier transform.
However, the Van Cittert-Zernike theorem requires the astronomical object to be incoherent. Certain astronomical objects are coherent. How are these coherent astronomical objects imaged?