Cosmology with Exotic Stars – Across the HR Diagram

by Alex Hackett (FZU - Institute of Physics of the Czech Academy of Sciences)

Thursday 22 May 2025, 14:00 → 15:00 Europe/Prague

Abstract: 

Fred Hoyle once stated that he considered stars to be "basically, simple things". Since the dawn of modern stellar astrophysics however, theoretical and observational work alike have increasingly come to challenge this perspective. In this talk, I will give an overview of the work that I have done over the past few years on the topic of exotic stars – those stellar objects that arise via non-canonical evolutionary pathways or in unusual environments. I will also show the surprising degree to which modern cosmology and Galactic Astrophysics – from large scale simulations to understanding the chemical evolution of the Universe, rely on understanding these objects. This ranges from the very largest stars, that came into existence when the Universe was just a fraction of its current age, to hybrid stars that result from complicated binary evolution processes such as common envelope evolution, to exotic highly magnetised stellar remnants. These stars and star-like objects influenced the wider Universe by impacting reionization, altering the rates of SNeIa that we rely on as a cosmological distance indicator, and a whole host of other unexpected effects. When we give an overview of this work we can increasingly understand the extent of Hoyle's understatement!! 

 

 

The seminar will be held in the Dvořák hall, FZU, Pod Vodárenskou věží 1, Prague.

Location: https://goo.gl/maps/wEf7PsiLimSXMZhE9

 

The seminar will be also available via ZOOM video conference system:

Meeting ID: 674 9629 6646
Passcode: 575511

or join meeting via direct ZOOM link

 

invitation_2025_05_22_Hackett.pdf