The 4th CO5BOLD Workshop
The 4th CO5BOLD Workshop
In astronomy, the modelization of stellar atmospheres constitutes an important step in the interpretation of stellar spectra. With the help of model atmospheres a wealth of information can be extracted from stellar spectra, like the basic atmospheric parameters of a star (effective temperature, surface gravity), its rotation rate, its chemical composition at the surface, as well as properties of the kinematics of potentially present hydrodynamical flows. Historically, stellar atmospheres were described as time-independent, one-dimensional, hydrostatic configurations in thermal equilibrium. While such models were adequate for several decades, the ever increasing quality of observational material has revealed shortcomings. In the realm of cool star it was realized that gas-dynamical effects are important in shaping the physical properties of their atmospheres. Consequently, this has spawned efforts to develop more sophisticated models accounting for the time-dependence and multi-dimensional nature of the gas flows taking place in the surface layers of cool stars. In parallel to the development of improved atmospheric models one is in need of an equally accurate description of the processes leading to the formation of a stellar spectrum, in particular of the formation of spectral lines. Often, one is confronted with conditions demanding for a detailed description of the underlying microscopic plasma processes. This constitutes a complex problem combining aspects of atomic physics and radiative transfer. The construction of model atmospheres and spectral syntheses both are computationally intensive tasks that require the development of efficient and robust algorithms making use of the ever-increasing capabilities of computer hardware.
For more than two decades a group of researchers has dedicated efforts to develop a hydrodynamical stellar model atmosphere code - the CO5BOLD code -, and associated spectral synthesis codes. With this workshop we would like to bring together the involved researchers who are scattered out over several institutes. The idea is to discuss the status of the developments and lingering problems, review the various applications of the codes, and organize efforts for future developments. The intention is to keep the number of participants rather small (less than 25) to give everybody the possibility to present her/his work, and give also significant room for discussion. The participation will be mostly by invitation plus a small number of additional participants from within the Sonderforschungsbereich "The Milky Way System" located in Heidelberg. This is the fourth workshop of this kind, after similar events in Freiburg 2006, Heidelberg 2012, and Napels 2016.
Zentrum für Astronomie - Landessternwarte
Prof. Dr. Hans-Günter Ludwig
Königstuhl 12, 69117 Heidelberg
Telefon: 06221 54 1788