We analyzed the shapes of Galactic open clusters by the star counting technique with the 2MASS star catalog database. Morphological parameters such as the ellipticity and size have been derived via stellar density distribution, weighed by clustering probability. We find that most star clusters are elongated, even for the youngest star clusters of a few million years old, which are located near ...

This thesis is devoted to star formation from galaxy-scales (≈ 10 000 pc) to sub-star cluster-scales (≈ 0.1 pc). I develop and test a new method to derive star formation histories of Galaxies from their star cluster content, in particular the most massive star clusters. This is followed by an application of this method to the Large Magellanic Cloud, where the results of this new method are conf...

We investigate the recent and current star formation activity of galaxies as function of distance from the cluster center in a sample of 521 SDSS clusters at z < 0.1. We characterize the recent star formation history by the strength of the 4000Å break and the strength of the Balmer absorption lines, and thus probe the star formation history over the last ∼ 2Gyr. We show that when the Brightest ...

After the stars of a new, embedded star cluster have formed they blow the remaining gas out of the cluster. Especially winds of massive stars and definitely the onset of the first supernovae can remove the residual gas from a cluster. This leads to a very violent mass-loss and leaves the cluster out of dynamical equilibrium. Standard models predict that within the cluster volume the star format...