Letters of Intent received in 2015

LoI 2017-297
From young circumstellar disks to planetary systems

Topics

Structure, evolution, and demographics of protoplanetary and debris disks.

Planet formation, accretion of solids and gas, comparison with exoplanet observations.

Disk/planet interactions.

Initial elemental abundances in planet formation.

Exoplanet demographics (results from Kepler, transit, radial velocity, microlensing and direct imaging surveys).

Exoplanet atmospheres (transmission and emission spectroscopy; ground and space based results; prospects for JWST).

Avenues in instrumentation and experimental astrophysics.

Dynamical evolution of planetary systems.

Rationale

Resolved optical-IR observations of circumstellar disks, along with exoplanet demographics measurements of exoplanet atmospheres and theoretical models, allow a complete overview of the evolution of planet-forming systems. These topics are at the forefront of Astrophysics and offer different approaches to understand the formation and evolution of exoplanetary systems, arguably one of the most active research areas in modern Astrophysics. The multidisciplinarity and wide breadth of current research warrants regular symposia encompassing all aspects of the problem to identify milestones, and provide a broad picture of planets all the way from their formation to their final configurations. The NASA mission TESS, which focusses on finding rocky planets around all bright, close by stars, will launch in 2017. It is also one year before the planned launch of JWST. Therefore this symposium will provide an excellent forum to discuss how scientists can use the coming results of these two missions to complement them with ground based observations as well as inform planet formation theory. In addition several large ground-based exoplanet surveys will have produced their first results by then, including the first few years of ALMA observations of planetary discs and formation processes with the full 12m array and next-generation high-contrast imaging surveys. As a host to ALMA, the GPI and SPHERE instruments and the upcoming E-ELT, Chile is a very appropriate host for this symposium. This symposium can also bring attention to Chile’s increasing role in exoplanetary research.

Understanding the origin of planets is motivating a concerted and world-wide effort in technology, involving key observatories and theoretical breakthroughs. Resolved observations of the gas dynamics in protoplanetary disks are revealing new insights on the physics of giant planet formation, and on the role of grain growth via aerodynamic coupling. In turn, the chemical abundances in the gas phase and on grains can be related to the elemental abundances of protoplanets. Evolution continues in the debris disk phase and the observed structures of such disks can reveal the ultimate architecture of planetary systems, which can be contrasted with exoplanet demographics after taking into account their dynamical evolution. The diversity of exoplanetary atmospheres inherits from this complex evolution and yet many pieces are still missing to link observations to planet formation theory, that will be addressed in this meeting. Observations of extrasolar giant planets have provided new insights into their atmosphere and dynamics. While there are many open issues that will be topics in this meeting, this meeting is timely to discuss how we can leverage lessons learned for extrasolar giant planet observations for future rocky planets observations.

The complexity of planet formation and evolution requires regular meetings to consolidate results, identify convergence points and establish foundations on which to conduct further multidisciplinary progress. The last IAU symposium that encompassed most aspects of current research on planet formation and evolution was held in Victoria in 2013 (IAUS299), more than two years ago. Since then, aspects involving young stellar populations were discussed in IAU Symposium 314, on “Observations of young stars and planets near the Sun”, held in Atlanta in 2015. The IAU General Assembly in Hawai’i also covered topics of planet formation in parallel sessions on transversal questions in astrophysics. Therefore, an IAU Symposium in 2017 seems very timely to establish milestones in the field of planet formation and evolution.

Easter Island is an attractive venue, where researchers will be devoted to the meeting without the distractions of large cities. The local organizers have access to complementary sources of funding in Chile that will be used to alleviate the costs of travel and accommodation; we anticipate we can at least match the funds the IAU would invest in the symposium. The venue would be the Hanga Roa hotel, that has already been succesfully booked for previous and upcoming conferences in Physics (nanoscience) and Astrophysics (http://www.sn2016.cl/, http://www.einc2013.cl/). The main meeting room at the Hanga Roa hotel room can house upwards of 300 people. The main drawback of the venue is the lack of fast internet connectivity, but we do not see this as major problem and indeed it may actually be seen as beneficial to ensure concentration on the meeting. That said, connectivity is certainly good enough to keep up with email. Travel costs to Easter Island are on the order of an additional ~300 USD than those to travel just to Santiago, which has direct connections to Australia, North America and Europe, and is a route well known to most astronomers. As a major touristic destination in Chile, Easter Island has a wide range of accommodation options, and the lodging costs are rather modest considering that we will be holding the meeting in the off-season (formally it will be winter, but weather is very mild given the sub-tropical weather in the island). As a way of example, the nanoscience conference alluded to above that was held in 2013 negotiated prices ranging from USD 90 to USD 200 per night for a single room in three hotels; there are more options at both the high and low end. Finally, we note that Easter Island, and in particular its only settlement Hanga Roa, is very compact, which means the vast majority of lodging options allow for easy access to the conference venue.

We have contacted a number of people to form a tentative science organizing committee (SOC), aiming at wide regional representation. The current proposed SOC includes the following researchers who have agreed to participate should our symposium plans materialize:
Simón Casassus (Universidad de Chile and ICM, Chile; co-chair)
Andrés Jordán (Pontificia Universidad Católica de Chile and ICM, Chile; co-chair)
Phil Armitage (University of Colorado, Boulder, USA)
Lucas Cieza (Universidad Diego Portales and ICM, Chile)
Subo Dong (KIAA, Peking University, China)
Thomas Henning (Max-Planck-Institut für Astronomie, Heidelberg, Germany)
Lisa Kaltenegger (Cornell, USA)
Sarah Maddison (Swinburne, Australia)
Dimitri Mawet (Caltech, USA)
Hideko Nomura (Tokyo Institute of Technology, Japan)
Didier Queloz (University of Cambridge, UK / Observatoire de Genève, Switzerland)
Hilke Schlichting (MIT, USA)
Mark Wyatt (University of Cambridge, UK)

The symposium would include outreach activities involving the local community. The LOC is committed to outreach, examples of activities can be found at http://madnucleus.com.

LOC:
Gesa Bertrang (Universidad de Chile / Universidad Diego Portales / Millennium Scientific Initiative)
Simon Casassus (Universidad de Chile and MSI)
Lucas Cieza (Universidad Diego Portales and MSI)
Virginie Faramaz (Pontificia Universidad Católica de Chile)
Andrés Jordán (Pontificia Universidad Católica de Chile and MSI)
Alice Zurlo (Universidad de Chile / Universidad Diego Portales / MSI)