Dr. Hsin-Yu Chen

University of Austin Texas

Observations of GW170817 strongly suggest that binary neutron star mergers produce rapid neutron-capture nucleosynthesis (r-process) elements. However, it remains an open question whether these mergers can account for al the r-process element enrichment in the Milky Way’s history. In particular, the neutron star merger-only enrichment scenario has been shown to be inconsistent with the observed r-process abundance trend of stars in the Galaxy. In this talk, I wil show the constraints on the contributions of the neutron star merger channel using recent astrophysical neutron star observations, including gravitational waves, radio, X-ray, and gamma-ray observations. I will then present a Bayesian framework to consistently combine these lines of observations with r-process abundance data to quantify the contribution and uncertainties of single and multiple astrophysical enrichment sources.

Dr. Camilla Hansen

Goethe University Frankfurt

Dr. Yutaka Hirai

Koeki University

Chemical abundances of stars reflect the origin of elements and evolutionary histories of galaxies. Spectroscopic and photometric observations have measured the chemical abundances of stars in the Milky Way and dwarf galaxies. We can extract the fossil records imprinted in stars by comparing such observations and chemical evolution models of galaxies. In this talk, I will review the recent progress in the modeling of galactic chemical evolution. I will show abundance ratios such as [Mg/Fe], [Sr/Ba], and [Eu/Mg] can resolve the chemical enrichment in a different timescale, and upcoming simulations will greatly improve our understanding of the origin of elements.

Dr. Franziska Maier

Michigan State University/ FRIB

With new radioactive-ion-beam facilities such as FRIB becoming operational, the properties of nuclei in close proximity to the driplines are coming within reach of high-precision measurements. Within the last year, at a fraction of FRIB’s ultimate beam intensity, we used the LEBIT facility [1] to successfully perform Penning-trap mass measurements of ¹⁰¹Sn [2], ¹⁰³Sn [3], ²³Si [4], and ²²Al [5]. These masses are critical for nuclear astrophysics and nuclear structure studies. They provide insights into the smoothness of the mass surface, help assess isospin symmetry breaking and offer valuable anchor points for nuclear models – especially for predicting properties near the driplines, where experimental data remain scarce. As FRIB ramps up its beam intensity, the production of many more nuclei will enable new and exceptional research opportunities. However, the short half-lives of many of these nuclei pose challenges for Penning-trap mass spectrometry. To overcome these limitations, we are developing a next-generation multi-reflection time-of-flight (MR-ToF) device at FRIB based on the work in [6].

In this contribution, I will discuss the mass measurements of ^101,103Sn, and ²³Si and highlight their significance for nuclear structure and nuclear astrophysics. Additionally, an overview of the ongoing development of a next-generation MR-ToF device will be provided, that will expand the mass measurement and separation capabilities of FRIB.

[1] R. Ringle, S. Schwarz and G. Bollen, Penning trap mass spectrometry of rare isotopes produced via projectile fragmentation at the LEBIT facility, IJMS 349-350, 87 (2013).

[2] C.M. Ireland, et al., In preparation.

[3] C.M. Ireland, F.M. Maier et al., High-Precision mass measurements of 103Sn restores smoothness of the mass surface, PRC 111, 014314 (2025).

[4] F.M. Maier, et al., Exploring Isospin Symmetry Breaking in Exotic Nuclei: High-Precision Mass

Measurement of 23Si and Shell-Model Calculations of T = 5/2 Isotopes, submitted to PRC.

[5] S.E. Campbell et al., Precision Mass Measurement of the Proton Dripline Halo Candidate 22Al, PRL 131, 152501 (2024).

[6] F.M. Maier et al., Increased beam energy as a pathway towards a highly selective and high-flux MR-ToF mass separator, NIMA 1056, 168545 (2023).

Dr. Ágnes Mócsy

Pratt Institute

Dr. Matthew Mumpower

Los Alamos National Laboratory

The heaviest elements on the periodic table are thought to be synthesized in environments with a copious number of free neutrons. The short half-life of neutrons (~ 15 minutes) limits viable candidate locations for nucleosynthesis. In the interior of stars, neutrons are contained in nuclei or produced slowly through nuclear reactions, limiting their viability for robust nucleosynthesis. I discuss an alternative pathway to generate neutrons in situ via the interaction of light and matter in an energetic jet occurring during the collapse of a massive star. Conditions for the i-process (intermediate neutron capture) and the r-process (rapid neutron capture) may be possible. I cover the implications of this phenomena and discuss how it may change the contemporary purview of heavy element nucleosynthesis.

Dr. Mathieu Renzo

University of Arizona

Massive stars, their explosions, and their compact remnants are a key driver of the chemical evolution of the Universe. It is uncontroversial that the vast majority of these stars are born and live in high multiplicity systems, where binary interactions can modify their internal structure, evolution, and final fate. The stellar structures resulting from binary interactions cannot be produced by single stars, and the differences (for example in terms of rotation, core sizes, density distribution) are significant enough to change nucleosynthetic predictions. Donor stars stripped of their envelopes burn helium at lower T and higher ρ producing relatively more carbon. Accretor stars spun up by mass accretion may be a dominant source of s-process.

Regardless of the pre-collapse evolution, the details of heavy element fusion are key to the formation of the collapsing core, and systematic uncertainties in progenitor structure are a key limiting factor in understanding SN explosions. This impacts single and binary stars alike, core-collapse and pair-instability supernovae. I will briefly describe recent developments in stellar physics calculation relying on modern computational techniques that could open the way for the exploration of these uncertainties.

Dr. Luis Acosta (IANNA)

Instituto de Estructura de la Materia, CSIC, Spain

The Ibero-American Network of Nuclear Astrophysics (IANNA) was created in 2022 to foster collaborations related to nuclear astrophysics between research institutions in Mexico, Spain, Brazil, Argentina, Portugal, and the United States of America (USA). The IANNA studies cover the nuclear reactions in stars and the chemical elements they create and disperse in the cosmos as well as the development of several detection systems and calculations to approach such reactions and their modelling. IANNA is as well a good platform for the students exchange across the involved countries, either in the development of experiments or their training in experimental and theoretical techniques.

IANNA was included officially as IReNA partner in March 2023, joined forces from both networks to combine their expertise, resources, and access to cutting-edge technology. Since that year, the Latin Network has not stopped their research and outreach activities in USA research institutions, where the support from IReNA has been vital. As examples might be mentioned one international Workshop (Notre Dame, June 9-11, 2024); one experimental campaign to measure the reaction rate in $^4$He(nn,$\gamma$)$^6$He, aimed to estimate its impact on the r-process (with researchers from USA, Mexico, Spain, Portugal, Brazil and Italy); and, one Summer school, ongoing organization (July 21-25 2025 at Beaver Island, Michigan).

In the present talk it will be described most of the activities developed by IANNA network and our further plans, where new measurements, outreach activities and student exchange are considered, as well as the participation of new countries and the possible collaboration with other networks linked to IReNA.

Dr. Daniel Bemmerer (CHETEC-INFRA)

Helmholtz-Zentrum Dresden-Rossendorf

Dr. Falk Herwig (CaNPAN)

University of Victoria

Dr. Takahiro Kawabata (UKAKUREN/JaFNA)

Osaka University

In this talk, I will report our activities on behalf of Japan Forum of Nuclear Astrophysics (UKAKUREN). UKAKUREN was established in 2008 to promote collaboration and communication among researchers in nuclear astrophysics in Japan. Currently, it has approximately 180 members from various fields, including astronomy, astrophysics, planetary sciences, particle physics, and nuclear physics.

UKAKUREN organizes an annual workshop and hosts bi-monthly seminars to facilitate information exchange among its members. In 2023, with support from IReNA, we successfully organized the 1st IReNA-Ukakuren Joint Workshop at the National Astronomical Observatory of Japan. The workshop was attended by over 70 participants, including 10 from US. We are now preparing for the 2nd joint workshop with IReNA in September 2025 in Osaka, Japan.

Additionally, starting this year, we have introduced two new awards to encourage young researchers: the Young Researcher Award and the Master’s Thesis Award. The recipients of these awards will be invited to give a lecture at the annual UKAKUREN workshop.

Through these activities, UKAKUREN continues to support and strengthen the nuclear astrophysics community in Japan while promoting international collaboration.

Dr. Chiaki Kobayashi (BRIDGCE)

University of Hertsfordshire

Dr. Hendrik Schatz (CeNAM)

Michigan State University/ FRIB

Dr. Achim Schwenk (EMMI)

TU Darmstadt