Illuminating the Cosmos: Chemical Elements in Stars, Planets, Nebulae, and Transient Extra-galactic Events

Session

Kilonovae

12 Nov 2026, 09:10

Auditorium (Haus der Astronomie)

35. The diversity of kilonova spectra in 3D NLTE

Blanka Világos (Stockholm University)

12/11/2026, 09:10

Kilonovae

Talks

Kilonovae (KNe) are one of the most important keys to understanding r-process nucleosynthesis. However, their observables are very challenging to interpret, as they are made of a mixture of r-process elements with very complicated atomic structures that expand at extremely high velocities. Other difficulties include the asymmetric nature of the ejecta and the rapid drop in density into a...

10. r-process formation channels- The dominant & the Sub-dominant

Yossef Zenati (Astrophysics research center of the Open University of Israe; Johns Hopkins University)

12/11/2026, 09:30

Kilonovae

Talks

Stellar abundances show non-monotonic evolution of [Y/Eu] and [Sr/Eu]: a decline with increasing [Eu/H] at low metallicity, a minimum at $[\mathrm{Eu/H}] \sim -0.3$, and a rise at high metallicity. This pattern necessitates at least three distinct neutron-capture sources acting on different timescales. We develop a one-zone chemical evolution model to constrain their delay times, rates, and...

21. Elemental Signatures in Nebular Kilonova Spectra

Smaranika Banerjee (University of Oxford)

12/11/2026, 09:50

Kilonovae

Talks

Binary neutron star (BNS) mergers provide a unique cosmic laboratory for understanding the origin of heavy elements ($Z > 26$), solving a long-standing mystery in astronomy. In the neutron-rich ejecta from these mergers, heavy elements are synthesized through rapid neutron capture nucleosynthesis ($r$-process). The radioactive decay of these freshly produced nuclei powers...

14. A General Analytic Diffusion Framework for Viewing-Angle Effects in Explosive Transients

Daniella van der Boom

12/11/2026, 11:10

Supernovae

Talks

The rapid growth of transient astronomy has highlighted the profound impact of multi-dimensional asymmetries—such as off-center radioactive distributions and jet-like structures—on observed light curves. While numerical Monte Carlo simulations capture these geometric effects, they often obscure the underlying physical intuition. In this work, we present an innovative analytic diffusion...

31. Atomic data impacts on nebular phase kilonova spectra: a case study of tellurium

Quentin Pognan (Max Planck Institute for Gravitational Physics (Albert Einstein Institute))

12/11/2026, 11:30

Kilonovae

Talks

A favoured channel for the creation of rapid neutron capture (r-process) elements is the merging of binary neutron stars, for which only two spectroscopically confirmed events exist: AT2017gfo and AT2023vfi. While the spectra of these objects have revealed r-process signatures, inferring elemental abundances remains a challenge. In the photospheric phase, large expansion velocities of...

74. Chemical evolution with mixing stochasticity

Anmol Aggarwal (University College London)

12/11/2026, 11:50

32. Neutrino transport fidelity in 3D collapsar disks: multigroup effects, moment-closure errors, and flavor instabilities as r-process diagnostics

Andrew MacFadyen (New York University)

Kilonovae

Talks

In collapsars, the accretion disk formed inside a collapsed rapidly rotating massive star emits neutrinos that set the electron fraction of its outflows — and with it the heavy-element yield of a candidate r-process factory. The neutrino field is semi-transparent, anisotropic, and energy-dependent, making transport fidelity a first-order uncertainty in predicted nucleosynthesis. I present 3D...