Yearbook 2009

The Southern Ocean is strongly affected by global change. A long-term study of Thin-billed prions, a small seabird feeding on zooplankton in these vast ocean areas, was designed to further our understanding of the changes that currently take place in this ecosytem. Further, this study will look at adaptations that enable the birds to cope with changing conditions, such as flexible provisioning behaviour and physiological regulation of timing and investments in the breeding cycle. more

Due to their mineralized content, teeth are by far the most commonly preserved remains in the human fossil record. The structure of the basic modules of teeth provides clues about the development and diet of humans and their fossil ancestors as well as their relation to the environment. Scientists of the Max Planck Institute for Evolutionary Anthropology make use of this biological source of information to find out in which ways modern humans differ from other primates and when and how the fossil ancestors of modern humans passed the threshold to anatomical and cultural modernity. more

The Caucasus has too often been reduced to ethno-nationalist conflicts. Researchers at the Max Planck Institute for Social Anthropology analyse how civil, political, and social components interact and how citizenship is compared between historical and contemporary notions and practices. Social citizenship continues to be relevant, especially for citizens who are detrimentally affected by migration, whether forced or voluntary. more

Several hundred Brown Dwarfs have been identified in the solar neighborhood and seem to be as numerous as main sequence stars. But the models for their structure and evolution are not as reliable as the models for stars. Spatially resolved binary systems offer a unique opportunity to determine the masses without using models, but such cases are rare. A group at the MPIA has now succeeded in determining the parameters of the Brown Dwarfs Kelu-1A and B. Conclusion: Existing models yield masses which are too low. The spectra also suggest the presence of an invisible third Brown Dwarf in Kelu-1. more

A group of astronomers headed by the Max Planck Institute for Astronomy has measured the velocity of the stars in the galactic halo and thereby derived the most accurate value to date for the total mass of the galaxy: The region within a radius of 200 000 light years contains 4×10¹¹ solar masses. An extrapolation to 800 000 light years leads to 10¹² solar masses. This result shows that the mass of the Milky Way has previously been significantly over-estimated. It also proves that our Milky Way has been extraordinarily efficient at forming stars. more

Scientists of the Max Planck Institute for Astrophysics and the Cluster of Excellence "Universe" at the TU Munich show by detailed computer simulations how the interaction of neutrinos may cause supernova explosions of stars with 11 to 15 solar masses. more

A team of astronomers, including members of the Max Planck Institute for Astrophysics, have combined the observational power provided by the Hubble Space Telescope with the predictive power of the Millennium Run cosmological simulations to investigate an intriguing cosmic puzzle. If luminous quasars in the early Universe mark the regions that were the first to collapse and form massive clusters of galaxies as predicted by theory, then why is the observational evidence for such cosmic "cities-under-construction" currently so scarce? more