Units

Astronomy and Astrophysics Institute

Person in charge of the Unit : Oui

The IAA is involved in theoretical and observational research activities in various fields of astrophysics. These concern in particular the synthesis of atomic nuclei, the chemical and isotopic composition of the solar system and of stars from our Galaxy, the structure and evolution of low- and intermediate-mass stars including diferent mixing processes as well as the modelling of binary systems and of stellar hydrodynamic phenomena of the detonation type. The modeling of the above phenomena is compared with observed quantities, like the chemical composition of stars from various classes. The chemical composition is derived using the best tools, both observational (telescopes and spectrographs from the European Southern Observatory, or from our own high-resolution spectrograph HERMES) and theoretical (model atmospheres, atomic and molecular data). Similarly, nucleosynthesis predictions require many nuclear data which are collected and evaluated, or generated in large-scale theoretical calculations. They are used to generate extended nuclear reaction networks which are made available to the astrophysical community. Besides these research topics where I.A.A. has long been recognized has an international centre of excellence, I.A.A. nowadays contributes substantially to the preparation of the E.S.A. Gaia mission. Astrometry and galactic dynamics are therefore two new active research fields at I.A.A.

Projetcs

Chemically peculiar stars and binarity : observational and theorical studies.

Multi-spectral analysis of chemically peculiar red giant stars (barium stars, S stars, symbiotic stars, metal-deficient carbon stars), determination of their evolutionary status. Studies of circumstellar environments (CO envelopes, dust, mass loss). Photometric monitoring of possible eclipsing, ellipsoidal or symbiotic binaries. Long term monitoring of radial velocities aiming at deriving their orbital elements. Spectroscopic determinations of chemical abundances