Federico Gonzalez (Universidad Nacional de San Juan)
Most massive stars reside in binary or higher-order multiple systems, with important consequences for their evolution. In young stellar clusters and associations, massive multiple systems may also play a significant role in shaping the dynamical evolution of the clusters. Over the past two decades, substantial progress has been made in the observational characterization of stellar multiplicity, as well as in the detection of magnetic fields and chemical peculiarities in massive stars. In this talk I will present selected observational results that highlight the importance of multiplicity, dynamical interactions, and stellar mergers in understanding the properties of massive stars. I will also discuss ongoing work investigating the dynamical evolution of an open cluster hosting a massive quadruple system which constitutes a substantial fraction of the cluster core mass.
Radek Poleski (OAUW)
Christian Ikechukwu Eze (CAMK PAN)
Leatitia Gibaud (University of Białystok)
Mikołaj Korzyński (CFT PAN)
Sebastian Trojanowski (Astrocent)
On October 6, 2026, the Nobel Prize in Physics was awarded to Francis Halzen "for decisive contributions to the IceCube Neutrino Observatory and the discovery of high-energy neutrinos of astrophysical origin". A particle theorist by training, Halzen has often remarked that he ended up leading a massive experimental collaboration at the South Pole "by accident", making this prize a tribute to the synergy between theory and experiment. Because TeV-PeV neutrinos are born in high-energy proton collisions and travel through dense matter without being absorbed or deflected, they allow us to pinpoint the cosmic accelerators where protons reach extreme energies. In this talk, I will discuss how a cubic kilometer of Antarctic ice was turned into a giant particle detector, and how IceCube simultaneously probes the environments around supermassive black holes and particle interactions at energies beyond terrestrial colliders.
Dorottya Szesci (Nicolaus Copernicus University, Toruń)
The metal-poor, irregular dwarf galaxy called I Zwicky 18 has been suggested to harbor (theorized) progenitors of Gravitational-Wave emitting mergers. The galaxy emits an unprecedented amount of hard ionizing radiation together with certain emission features in its spectrum. To explain this, a theorist like me has to put together a complex hypothesis based on reliable computer models of those stars, and compare its predictions to all available observations in the literature. Sounds easy, right? But what if she finds that the observations *themselves* actually contradict each other? Then she has no choice but go down the rabbit hole of learning how observational astronomers work, speak, and think – a scientific challenge in itself. In this talk, I share my curious story of the past 12 years tackling the case of I Zwicky 18, and my hunt for finding observational evidence for the existence of a certain type of GW progenitors, which have just come to an end. (Relevant paper: A&A 703 A131)
Parikshit Biswas (CAMK, Warsaw)
