Research Interests:

Current Science Activities:

• Founding member of the Chilean FONDAP Center for Astrophysics  in 2001. Principal Investigator of the "Extragalactic Distance Scale" research area of the Center

• Principal Investigator of the Araucaria Project. This project aims at  providing improved calibrations of the dependences of stellar distance indicators (Cepheids, RR Lyrae stars, red clump giants, blue supergiants)  on the environmental properties of their host galaxies. This research is expected to lead to a significant improvement in the measurement of absolute distances to nearby galaxies, with direct consequences for the distance ladder and cosmology. For more details, check out the Araucaria Project homepage

• Co-Investigator in the extrasolar planets and brown dwarfs area of the FONDAP Center for Astrophysics (science activities in this area are headed by Maria Teresa Ruíz). We are currently obtaining high-resolution spectra with VLT/UVES and Magellan/MIKE to measure the radial velocity curves of selected solar-like stars which show transits in the OGLE  photometric database. The combined radial velocity and photometric data should clarify the nature of these transiting objects, and allow a precise determination of their fundamental physical parameters

• Co-Investigator of the NASA Space Interferometry Mission Key Project  "Taking Measure of the Milky Way" in which our group, led by Steven R. Majewski of the University of Virginia, will undertake fundamental measurements of the gravitational potential (mass distribution) and dynamical structure of the Milky Way galaxy

• Co-Investigator of a NASA project to provide radial velocity follow-up observations of giant stars in the Galactic halo which will be used as astrometric grid stars for the Space Interferometry Mission satellite. These observations are necessary to define the final sample of grid stars for the mission, by weeding out stars showing complications (e.g. binarity) compromising their use as astrometric grid stars