Theoretical considerations lead to the expectation that stars should not have masses larger than about m_{max*}=60-120M_&sun;, while the observational evidence has been ambiguous. Only very recently has a physical stellar mass limit near 150M_&sun; emerged thanks to modern high-resolution observations of local star-burst clusters. But this limit

Effective temperatures of 30 turnoff stars with -3.2 {[Fe/H]{ have been derived from the profiles of Balmer lines in high S/N, VLT/UVES spectra. While the systematic error of Teff may be of the order of 100K, the differential values of Teff are determined with a one-sigma precision of ˜25K. These precise Teff values are used in a study of the slope

Cosmoeduca is an educational project set up by the Canaries Astrophysics Institute (IAC), with the support of the Spanish Ministry of Science and Technology, for teachers of all subjects at secondary school level. During this talk we shall discuss (a) How it all started, (b) What we hope to achieve and (c) The past, the present and the future.

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The Permanent All Sky Survey (PASS) is a project for a continuous photometric survey of the entire celestial sphere with a high temporal resolution. Its major objectives are the detection of all giant-planet transits (with periods up to some weeks) across stars up to mag 10.5, and the delivery of continuous time series photometry that is useful for

The popularization of science, as a part of Culture, has and continues to be a constant concern for the Instituto de Astrofísica de Canarias (IAC), reflected in important actions, such as public outreach campaigns at educational institutions, open days at the Observatories, courses and conferences, exhibits, cooperation with publishing companies