Wednesday Colloquium



11.05.2016

"(Nearly) Complete Census of Cepheids and RR Lyrae Stars in the Magellanic Clouds"

Igor Soszyński (Astronomical Observatory, Warsaw University)

More than a century after the pioneering works of Henrietta Leavitt we are close to identify and catalog all Cepheids and RR Lyrae stars in the Large and Small Magellanic Clouds. The OGLE-IV fields cover a large area in the Magellanic System, including its outskirts and the Magellanic Bridge spreading between both galaxies. The OGLE collection of pulsating stars is a basis of many extensive astrophysical studies on stellar evolution and pulsation theories, models of the structure and dynamics of the Magellanic Clouds, and the extragalactic distance scale.


18.05.2016

" The study of the ionized interstellar medium using radio pulsar observations."

Wojciech Lewandowski (Zielona Góra University)

When propagating through the interstellar medium the radio signals from pulsars are affected by a few phenomena occuring in the ionized matter. We see the evidence for the interstellar dispersion of radio waves, the scattering as well as the interstellar scintillations. While for the majority of pulsar astronomers these effects are a nuissance that has to be removed from the data, to be able to study these objects, they can be also a great source of information about the ionized fraction of the interstellar medium - its physical properties, turbulent nature and distribution within the Milky Way galaxy.


25.05.2016

"Meteorites - from exploration to research"

Zbigniew Tymiński (National Centre for Nuclear Research)