Symposium S8 2 - 3 July 2020

Common-envelope systems: progenitors, mergers and survivors

News: 8 Jan. 2020: updated list of invited speakers

Aims and scope

Most stars are born in binary or multiple systems, which usually interact during their lifetimes. The most extreme forms of contact are stellar mergers and common envelope events, when part of the primary stars envelope is expelled from the system. Recently recognized phenomena such as (luminous) red novae and their extragalactic analogs (known as intermediate luminosity optical transients or ILOTs) show that even low-mass stars can display spectacular outbursts in the Local Group. These merging systems had gone through the common-envelope (CE) phase, which is an essential channel for the formation of compact binary systems and some of the most energetic transients in the Universe. Despite its importance, this evolutionary phase is still poorly understood. In particular, questions such as the main progenitor channels, how the merged systems entered the common-envelope phase and properties of the outburst are far from clear. Moreover, observations show the existence of close binary systems which, according to theoretical predictions, should have inevitably merged during the common envelope phase.

The goal of the proposed symposium is to discuss the latest advances in the study of CE evolution in the context of stellar mergers and related phenomena. The meeting will combine observations and theory to probe where we stand in solving the problem of the CE and define avenues of future research in the field.


  • stellar mergers and CE transients
  • post-CE objects (central stars of planetary nebulae, cataclysmic variables, etc.)
  • and merger remnants: blue and red strugglers, anomalous Cepheids, Be & B[e] stars, η Car, FK Com stars, etc.
  • hydrodynamical modeling of the common envelope
  • common envelope evolution in population synthesis
  • radiation transport and shocks in the common envelope phase

Invited speakers

  • Jennifer Andrews (Univ. Arizona, USA)
  • Selma de Mink (CfA | Harvard & Smithsonian, USA)
  • David Jones (IAC, ES)
  • Morgan MacLeod (CfA | Harvard & Smithsonian, USA)
  • Gijs Nelemans (Nijmegen Univ., NL)
  • Paul Ricker (Univ. Illinois, USA)

Scientific organisers

chair: Tomasz Kaminski (NCAC Torun, Polish Academy of Sciences, PL),
Orsola de Marco (Macquarie Uniersity, AU),
Nadia Blagorodnova (Radboud University, NL),
Stephen Justham (University of Amsterdam, NL & University of the Chinese Academy of Sciences, CH),
Ondrej Pejcha (Charles University, CZ),
Silvia Toonen (University of Birmingham, UK)


tomkam @

Updated on Wed Jan 08 17:21:04 CET 2020