Coffee/tea and cookies will be in the coffee lounge of 52 Hillhouse starting at 2:00 PM. Bring your own mug if you have!
With ALMA in full production and JWST soon to launch, observations of still-forming planets embedded in protostellar disks are soon to come. Yet JWST observing time will be expensive, and ALMA can only detect a planet’s influence on nearby gas and dust, rather than the planet’s photosphere. I will discuss a set of markers that can pre-select promising exoplanet-hosting candidate disks for detailed observing campaigns. I will begin by demonstrating that the subset of accreting transitional disks with wide, optically thin inner holes of 15 AU or more can only be sculpted by multiple planets orbiting inside each hole. Next, I will present models of infrared and submillimeter emission from second-generation collisional dust created by a Jupiter-mass planet perturbing a gas+planetesimal disk. Synthetic images from our numerical simulations show a bright double ring at 850 μm for a low-eccentricity planet, whereas a high-eccentricity planet would produce a characteristic inner ring with asymmetries in the disk. In the presence of first generation primordial dust these markers would be difficult to detect, but they would be observable in a transitional disk with a mature planetesimal population. Finally, the properties of the planet-forming midplanes of protostellar disks remain largely unprobed by observations due to the high optical depth of dust and of commonly observed molecules such as CO and H2O. I will discuss a chemical model of an evolving T-Tauri disk that predicts the optical depths of rotational transitions of 13C16O, 12C17O and 12C18O. The optical depths of low-order rotational lines of C17O are around unity, which suggests it may be possible to see into active planet-forming midplanes using C17O. With our computed C17O/H2 abundance ratio, such ALMA observations would provide estimates of the gas mass available for planet formation.