Ast(e)rospheres*: From the Sun to Red Super Giants

9 – 13 December 2013


*one important conclusion of the workshop is that the commonly preferred terminology is asterosphere instead of astrosphere.




The main goal of the workshop “Asterospheres: From the Sun to Red Super Giants” was to bring together scientists with different backgrounds (observational vs. theoretical and numerical, hot stars vs. cool stars, solar physics vs. astronomy etc.) whose research focused on the interaction between stellar winds and the local ambient medium. By bringing scientists from such diverse backgrounds together we wanted to encourage an increase in cooperation and allow people to benefit from experience gained in different fields. In the course of the workshop, we achieved our main goal in opening a general dialogue between researchers from different fields. This allowed all participants to gain a better understanding of each other’s efforts. In the observational field we identified how observations at different wavelengths allow us to gain understanding of specific processes. Such data can be combined into a comprehensive picture of an asterosphere. In the theoretical/computational field we identified the physical processes that have to be included in accurate models of circum- and interstellar “bubbles” and the numerical techniques that can be used to implement those processes. We intend to write a review paper based on the contents of the workshop and are in the process of identifying the best venue for such a publication.




As originally envisioned, the workshop consisted of two major components:

• A small number of oral presentations, intended to inform the general audience of the issues in the speakers area of expertise and identify key scientific problems.

• Separate discussion sessions where the participants could work on these problems.


The initial idea was to separate the participants into groups, where they would discuss specific topics within the general framework of the workshop and report back to the general audience. The program had been designed around this format with time set aside both for the discussions and the final reports. In practice, this did not occur. The total number of participants ( 30) was small enough for effective general discussions where the whole group participated. This proved a positive development that allowed the participants to benefit from each other’s experience and henceforth allowed for a deeper understanding of the various astrophysical problems. Particularly, participants became much more aware of limitations, problems, and open questions in fields beyond their own expertise. During the week several smaller groups of participants got together to discuss ongoing and future research projects. As hoped and anticipated we particularly noted frequent interactions between observers and modellers.


Participants were unanimous in noting that regular meetings on the topic of astrospheres would be highly desirable, and advocated more coordinated research efforts, for example through the EU research collaboration framework, Horizon 2020. In summary, this Lorentz Center workshop managed to bring together experts from different fields working on asterospheres and related issues, and has given further impetus to the newly developing field of asterospheres.


Nick Cox (Leuven, Belgium)  

Vasilii Gvaramadze (Moscow, Russia)  

Lex Kaper (Amsterdam, Netherlands)  

Rosine Lallement (Paris, France)  

Allard Jan van Marle (Leuven, Belgium)