In the programme of IAU Symposium 241 we have included 2 so-called challenges. The two challenges consist of a set of well-defined problems in the field of stellar evolution and stellar populations that the participants can try to solve. For the stellar population challenge a few data sets (as standard as possible) are given for which the participant has to derive stellar population parameters. The data sets contain both resolved and unresolved data. For the stellar evolution challenge the participants are supposed to run a stellar interior model with accurate specifications for the input physics.
The results will be compared and discussed at the meeting in 2 sessions: one for each challenge. There have been challenges in the past (e.g. in Crete in 1995), and they have always proven to be very interesting. It is our aim that the community, and the participants in particular, learn from doing these controlled experiments. If these challenges also prove to be succesful, it is intended to publish the results including those who have contributed.
The challenged are organised by Achim Weiss (MPA) for the stellar evolution, and Scott Trager for the stellar populations. The necessary information can be found at: http://www.mpa-garching.mpg.de/stars/SCC/StarCode.html for the Stellar Evolution Challenge, and http://www.astro.rug.nl/~sctrager/challenge/ for the Stellar Population Challenge. We welcome everybody to participate, starting today!.
We hope you enjoy the challenge!