Research at the institute of Astronomy
|
|
Asteroseismology Observational studies of pulsating and variable stars have been conducted at Leuven University for half a century now, covering all stellar masses and evolutionary stages, but with specific attention to young massive stars, to red giants and to subdwarf stars on the horizontal branch. The Leuven seismic investigations of stars range from instrument development and building, data gathering, data analysis, methodology for data interpretation, to theoretical modelling of stellar structure. Emphasis gradually shifted from stellar pulsation theory, including asymptotic treatments, non-linear oscillations and tidally induced pulsations, to observational asteroseismology, in view of the opportunities created by high-resolution spectrographs and by dedicated space photometers for this field of research. For the ground-based observational studies, extensive use is made of the Mercator telescope at La Palma Observatory (Canary Islands), owned by the institute, and of its twin, the Swiss Euler telescope at La Silla (Chile). The institute is also heavily involved in asteroseismic space missions, such as MOST (Canada), CoRoT (French-led European), Kepler (NASA), and PLATO (ESA), as well as in the study of variable stars with the ESA cornerstone mission Gaia. Specialised methodology for time series analysis and mode identification of non-radial pulsations was developed in Leuven and is continuously being upgraded and made available to the international community.
|
|
|
Stellar Evolution In the context of stellar evolution, special emphasis is put on late stages of stellar evolution, in particular the AGB and post-AGB phases. We are specialised in the chemical history of such objects, by means of detailed abundance analyses and studies of s-proces nucleosynthesis. Attention is paid to the effects of binarity on the evolutionary phases after core hydrogen burning, all the way to the pre-white-dwarf phase. Another specific interest is to study all aspects of the circumstellar dust shells around these evolved objects, including the chemistry in that environment and the details of the mineralogy of the dust grains. A theoretical component is the research on the mass los and the mass-loss history of evolved stars, by means of modelling the molecular outflow through a state-of-the-art radiative transfer code developed in Leuven. For this research, we are involved in ground-based and space-based observations of evolved stars in the Magellanic Clouds, the Galactic Centre, and the solar neighbourhood. Extensive use has been made of data gathered with the past ESA infra red missions IRAS and ISO and with the NASA Spitzer satellite. We are presently heavily involved in the exploitation of data assembled with the instruments PACS and HIFI onboard the ESA cornerstone mission Herschel. Moreover, frequent use is made of the ESO instruments by means of competitive peer-reviewed proposals, in particular APEX, also with the goal to be ready for intensive and efficient exploitation of ALMA.
|
