Simulated interferometric patterns generated by a nearby star-planet system and detected by a rotational shearing interferometer

Simulated interferometric patterns of the wave fronts generated by a star-planet system and detected with a rotational shearing interferometer are derived analytically and presented graphically. They are identical to the patterns generated solely by a planet because of the insensitivity of the rotational shearing interferometer to the detection of a rotationally symmetric wave front. The variable shearing angle is shown to control the number of fringes and their orientation. For small shearing angles the phase difference in the argument of the cosine function reduces to the derivative of the wave front multiplied by the shearing angle. The analytical expression for the intensity detected with a rotational shearing interferometer demonstrates that the rotational shearing interferometer does not see the on-axis star. (C) 1999 Optical Society of America [S0740-3232(99)01607-5].