One of the most challenging questions of modern astronomy is how and when planet formation happens in protoplanetary disks. Recent advancements challenge key paradigms in planet formation and disk evolution theories. In particular, observations suggest that planet formation occurs earlier than previously thought in embedded systems, and, in the proposed scenarios there is a shift of consensus from classic viscous accretion to wind-driven accretion. Indeed, it appears that the interplay between accretion and ejection has a key role for the distribution of gas and dust in the disk, deeply influencing how planets form at early stages.

Other factors, yet to be fully explored, have important consequences for the evolution of the forming systems. Molecular snowlines, defined as the radius where molecules can condense into solid ice, are prime locations for planetesimal formation and shift outwards during accretion bursts. Accretion shocks occur both at the centrifugal barrier, the transition region between the infalling envelope and the accretion disk, and at the impact point of accretion streamers onto the disk. These slow shocks sputter dust grain mantles, enriching the volatile content of the gas and altering disk kinematics. Variability, magnetically driven jets from the inner disk and photoevaporation all have an impact on the disk conditions. Environmental factors must also be taken into consideration, as the ambient magnetic fields, external irradiation and the gravitational effects of source multiplicity impact the early formation and evolution of young disks. Finally, the process of transforming small dust particles into planetesimals requires specific conditions (e.g., large dust-to-gas ratios) which are yet to be verified in young disks.

Cutting-edge facilities such as ALMA, JWST and AO-assisted ground-based instruments are providing new and complementary results that enable us to explore the properties of young disks and winds for the very first time. At the same time, new models and numerical simulations are being developed to interpret those observations encompassing all the relevant processes.

In this special session, we aim to present the latest findings on disks and winds around young stars. The goal is to advance our understanding of the processes influencing the initial conditions for planet formation by fostering collaboration among communities studying different aspects of young protostellar disks and winds.

Programme

The Session is scheduled for Friday, July 5th, 2024.

The Session will be divided into four blocks, each of them covering one of the main topics:

1. Observational and theoretical perspectives on the formation of young disks
2. Impact of accretion and ejection processes on disk formation and properties
3. Planetesimal formation in early and evolved disks: the impact of dust accumulation, dust growth, snowlines, gravitational instabilities, magnetically driven winds
4. Disk and wind properties in multiple and variable young objects

Invited speakers

• María José Maureira (Max-Planck-Institute for Extraterrestrial Physics, Germany)
• Patrick Hennebelle (CEA Saclay, France)
• Sylvie Cabrit (Obs. Paris, France)
• Alessio Caratti o Garatti (INAF-OACN, Italy)
• Joanna Drążkowska (Max-Planck-Institute for Solar System Research, Germany)
• Marion Villenave (Univ. Milano, Italy)
• Nicolás Cuello (Univ. Grenoble Alpes, France)
• Dominique Segura-Cox (The University of Texas at Austin, USA)

Scientific organisers

Eleonora Bianchi (Excellence Cluster ORIGINS, Germany, chair)
Elisabetta Rigliaco (INAF, Italy, co-chair)

Francesca Bacciotti (INAF-OAA, Italy)
Catherine Dougados (IPAG, France)
Jochen Eislöffel (Thüringer Landessternwarte, Germany)
Eleonora Fiorellino (INAF-OACN, Italy)
Ugo Lebreuilly (Univ. Paris-Saclay, France)
Valentin Le Gouellec (NASA, USA)
Linda Podio (INAF-OAA, Italy)
Benoît Tabone (Univ. Paris-Saclay, France)
Leonardo Testi (Univ. Bologna, Italy)
Łukasz Tychoniec (Leiden Observatory, The Netherlands)
Emma Whelan (Maynooth University, Ireland)

Contact

eleonora.bianchi@origins-cluster.de
elisabetta.rigliaco @ inaf.it