Publications
of the
MPIfR Optical & Infrared Interferometry Group

T. Preibisch, A.G.A. Brown, T. Bridges, E. Guenther, H. Zinnecker

The star formation process in the Upper Scorpius OB association and implications for planet formation

Astronomische Gesellschaft Abstract Series (AGM 19, A06)
Der kosmische Materiekreislauf
Annual Scientific Meeting of the Astronomische Gesellschaft, Sep 23-28, 2002, Berlin, Germany

Abstract

We have performed a detailed investigation of the stellar population and star formation history of the Upper Scorpius OB association, the most nearby region of recent massive star formation. Our HR-diagram for 364 high- and low-mass members showed that the whole stellar population is well characterized by a very narrow age distribution around 5 Myr, suggesting that the star formation process in Upper Sco was triggered, most likely by a supernova shock-wave. We estimated individual masses for all members and found that the empirical mass function in the 0.1M to 20M range is consistent with recent determinations of the field initial mass function. Our result confirms earlier suggestions that most stars in our galaxy form in OB associations, i.e. close to massive stars. This implies that most planetary systems form in an environment where they are exposed to stellar winds, ionizing radiation, and supernova shock-waves from massive stars, which should significantly affect their evolution.