Program: GS-2004B-Q-1

We propose to measure the sizes of young stellar objects in the thermal infrared, a wavelength range which probes the region of the circumstellar disk where gas giant planets are expected to form. Previous attempts to obtain precisely calibrated imaging data with large aperture telescope have been frustrated by unstable atmospheric seeing which affects the time-averaged PSF. To overcome this, we will carry-out a novel sparse-aperture interferometry experiment to enable robust mid-IR diffraction-limited imaging. Specifically, we will utilize a cryogenic pupil mask (already installed in TReCS) to allow high-sensitivity (low-thermal background) aperture masking, yielding the well-established calibration advantages of sparse-aperture Fizeau interferometry.