Schedule of Talks
1:00 – 2:00 pm: Alice Booth (Harvard)
Title: Characterizing the Chemical Landscape of Planet Formation
Abstract: Planetary systems are made from the dust, gas and ice in the rotating disks around young stars. Therefore, the answers to some of the most pertinent questions in exoplanet science hinge on our knowledge of protoplanetary disk chemistry. High-sensitivity observations with the Atacama Large Millimeter Array allow us to detect and characterize emission lines from wide array of molecules in young disks. We can therefore, directly trace the composition of the gas available to be incorporated into forming planets and other smaller bodies. In this talk, I will show how we map the distribution of key elements C, N, O and S across disks, determine the availability of the precursor molecules needed for prebiotic chemistry, and even, directly detect newly forming planets. In particular, my research is revealing new elemental and isotopic reservoirs that are essential to trace back the formation conditions of mature exoplanet systems. To end, I will look to the future and discuss what can be learned from complementary observations of disks with JWST and what we can anticipate with the next generation of ALMA and the ngVLA.
2:00 – 3:00 pm: Luke Bouma (Carnegie)
Title: Hot and Cold: The Circumstellar Environments of Young Low-Mass Stars
Abstract: Over the past decade, photometric surveys conducted from space have opened tremendous opportunities for deepening our understanding of how exoplanets and stars evolve. Red dwarf stars in particular are enabling the study of close-in rocky exoplanets. However, the circumstellar particle and radiation environments of these stars differ from those of Sun-like stars, and these environments are observationally challenging to study. In this context, an important surprise has been the discovery that a small fraction of young red dwarfs show optical light curves with complex periodic variability, suggesting the presence of transiting clumps of opaque material corotating with the star for months to years. The composition, and even the existence, of this material have been debated. I’ll give an overview of this new area of study, describe competing interpretations of the data, and present new ground-based observations that argue for this phenomenon being associated with extended clumps of circumstellar plasma. In the coming decade, a firehose of data from Roman, JWST, Gaia, and TESS will continue to drive data-driven discovery in exoplanet and stellar astrophysics; these specific stars offer one case study of what can be learned from the surprises.
3:00 – 3:30 pm COFFEE BREAK
3:30 – 4:30 pm: Samuel Hadden (CITA)
Title: Probing orbital evolution in the outskirts of planetary systems
Abstract: Exoplanet discoveries over the past three decades have revealed an astonishing diversity of planetary systems. While we have uncovered an abundance of systems quite unlike our own, we still do not have a firm grasp on how exceptional our own solar system is. This will change in the near future when NASA’s Roman mission provides our first glimpse of the low-mass planet population beyond ~1 AU. I will describe how a deep understanding of how planets interact gravitationally will provide essential insights for interpreting Roman’s micro-lensing planet detections. In particular, this theory will link together the population statistics of bound and free-floating planets to give a comprehensive picture of how orbital evolution shapes the outer regions of planetary systems. This will allow us to place our own solar system in context, especially as Rubin LSST’s upcoming census of solar system small bodies offers a complementary opportunity to study the past orbital evolution of our own outer planets in unprecedented detail.
4:30 – 5:30 pm: Wenrui Xu (Flatiron)
Title: Towards an ab initio theory of planet formation
Abstract: Planet formation is a complex process. Observations of both exoplanet systems and protoplanetary disks reveal remarkable diversity, a result that is not unexpected given the numerous physical processes shaping planet formation. In this talk, I will discuss some recent breakthroughs in seeking the organizing principles of planet formation through multi-physics simulations and theories. Radiation non-ideal magneto-hydrodynamic simulations of protoplanetary disk formation and evolution show that the disk is initially massive and self-regulated by gravitational instability; the onset of planet formation is closely tied to the transition away from this highly turbulent gravitationally self-regulated state during the first 1-2 Myr of disk evolution. Once planet formation begins, planet-disk interaction provides important feedback mechanisms that shape the formation and dynamical evolution of multi-planet systems, leaving many observational signatures in planet architectures. Generalizing from these examples, I will discuss further steps toward developing an ab initio theory of planet formation.