91福利

Astronomy Seminar

Ben Davies
(Liverpool John Moores University)

The Brightest Stars in the Local Universe

When massive stars evolve off the main sequence, they become Red Supergiants - stars which are more luminous than entire globular clusters and dwarf galaxies. Accurately modelling such stars means that can then be used as probes with which to study the properties of their host galaxies at Mpc distances.

In my talk I will firstly discuss the atmospheres of these stars, and how we are only just beginning to understand the basic quantity of their temperatures. Secondly, I will describe our new project which uses these stars to chart the chemical evolution and star-forming history of their host galaxies at distances well beyond the Local Group.

By Prof. Mario Affatigato (Physics Dept., Coe College USA)

Location: PLT

Abstract:

In this talk we will present two techniques that have provided some new capabilities in the characterization (LITOF) and manufacturing (aerolevitation) of exotic glasses. The use of laser ionization combined with time of flight mass spectrometry has yielded several insights on the intermediate range structure of glasses, and we have moved towards quantification in the borate system. Aerolevitation started out as an advanced manufacturing technique that inhibits crystallization and can work at very high temperatures, and thus provides the ability to turn some nearly impossible compositions into glasses. Lately, we have begun an effort to incorporate the ability to detect and quantify crystallization as we cool the levitated beads.