Variability and Asymmetry of Molecular Emission From Protoplanetary Disks

Searches for planets around main sequence stars have shown that such systems are common, even ubiquitous. Direct imaging of protoplanetary disks around stars in their early stages likewise show features consistent with planet formation (e.g. gaps/cavities, rings, spiral arms). However, direct detections of planets themselves in disks are very rare. We have previously shown that high resolution infrared spectroscopy can be used to identify orbiting planets through their circumplanetary disk emission. Here, we will discuss results of infrared spectroscopic observations of disks, ranging from those with known planets to stellar binary systems. Special attention will be given to HD 141569, which may exhibit variability in the (a)symmetry of its CO ro-vibrational line profile.