Modeling and Observing DEense STellar systems

Bonn/Bad Honnef: December 4–8, 2007

The meeting is sponsored by » AstroSim/ESF, the » DFG Priority Programme 1177 - "Witnesses of Cosmic History" and the » Argelander-Institut für Astronomie.

Rhine valley
View over the Rhine valley near Bonn in winter. (Photo: Tobias Westmeier)

The stellar-dynamics group at the » Argelander-Institute for Astronomy (AIfA) wishes to invite the dense-stellar-systems community to the 8th annual meeting of the MODEST consortium, MODEST-8, and the fourth annual meeting of the » Rhine Stellar Dynamics Network, RSDN. For e-mail contact please use modest8 (at)

Scientific Rationale

The fundamental building blocks of galaxies are dense stellar systems: star clusters. These range from open clusters at the low-mass end to massive star-burst systems containing millions of stars, some of which may evolve to globular clusters. Ancient cluster systems test cosmological models as their constituents, the individual globular clusters, are among the first objects to have formed. The fraction of massive star-burst clusters that manage to hold together to form globular clusters remains unknown and heavily debated.

The physics of star-cluster formation has many unknowns, but it is becoming increasingly clear that the processes driving cluster assembly also have a significant impact on the morphology and kinematical properties of whole galaxies. Clusters re-shape their stellar population through dynamical encounters that dissociate multiple stars but which can also merge stars. Star clusters are environments in which gravitational dynamics meets stellar physics such that the evolution towards energy equipartition is significantly affected by stellar evolution since both time-scales are comparable. Dealing with these processes therefore poses extreme computational challenges, leading to the development of innovative software and hardware super-computer solutions. Because stars are of the same age and metal composition in most star clusters, these systems also offer excellent environments for testing stellar evolution theory. Observations of such systems stand therefore at the fore-front of observational astrophysics, ranging from star-by-star scrutiny to observations of extra-galactic star-cluster systems in old but also in massively interacting galaxies.

The aim of this meeting is to bring together researchers studying problems related to the above questions, with a non-exclusive emphasis on modelling star clusters together with stellar evolution, and observational tests thereof.


Holger Baumgardt, Michael Hilker, Piet Hut, Pavel Kroupa (chair), Steve McMillan, Rainer Spurzem, Simon Portegies Zwart


Holger Baumgardt, Claudia Brüns, Jörg Dabringhausen, Pavel Kroupa, Thomas Maschberger, Manuel Metz, Jan Pflamm-Altenburg


The MODEST-8 meeting will be taking place in the » Physics Centre of Bad Honnef nearby to Bonn. This is a beautiful ambiente on the River Rhine. Conference participants stay in the Physics Centre which also has its own beer cellar. The nearby » Christmas market in Bonn will provide some additional relaxation with one or more Gluehweins and other seasonal specialities.

Arrival and Departure

Please try to arrive at the Physics Centre on December 4th after lunch time. We have December 5th-7th as full days, and the end of the meeting is planned for Saturday, Dec.8th lunch (lunch included), although it is possible to stay at the Centre until Dec.9th. We suggest an excursion, for example to a Christmas Market, on Saturday afternoon.

We will be asking those registered for arrival and departure times in November, as we have to communicate this to the Physics Centre.


The programme can be downloaded as » pdf. The idea is to have an exchange between observers and theoreticians working on young clusters and old globular clusters and other dense stellar systems, and their distributions. We plan to incorporate plenty of time for discussions, including beer, also in small sub-groups.


The deadline for registration was November 5th. There will be no conference fee. It is planned that all participants stay at the Physics Centre in Bad Honnef, although hotels are also available in Bad Honnef. There are about 80 beds available at the Physics Centre, some of which are in double rooms. The cost of staying at the Physics Centre is about 55 Euro per night, which includes three meals per day and the coffee breaks. Please try to arrive by December 4th for dinner in the Centre. Please note that those staying in a hotel will have to pay a fee of 40 Euro each day to the Physics Centre for coffee breaks, lunch and dinner. Shortly after November 5th we will send a mail to those registered asking about arrival and departure dates to finalise the booking of the Physics Centre rooms.

For enquiries please contact: modest8 (at)

Panorama of Bad Honnef and surroundings

Below we have compiled a panorama picture of the Rhine valley between Bad Honnef and Bonn. Move your mouse on the picture and it will start to scroll. Please note, that display problems may occur when using old browsers.


To scroll, please move the mouse over the picture. (Photo: Tobias Westmeier)

Last update: December 21, 2007