I spent a month at the Universidad de Valparaíso from the 3rd March until the 2nd April working with Michel Curé and Catalina Arcos. During my stay, we wrote a joint proposal to observe OB stars in a low metallicity environment. In addition, I learned how to use the hydrodynamics code HyDWIND and more about the m-CAK theory for modelling line-driven winds. We tried to mimick the output velocity profile of HyDWIND with PoWR in order to model the spectral lines of OB stars, and compare with other codes synthetic spectra such as FASTWIND. I also actively participated in the group seminars and discussions.

I had time to visit the area and try the delicious Chilean food. During the weekends, we visited the nearby cities such as Viña del Mar and Concón. We also spend some days in Santiago visiting collaborators at ESO Vitacura. I loved the city of Valparaíso and it was a great pleasure to spend my time working there, everyone in the group of Michel was extremely welcome and made me feel like home. Looking forward for more collaborations in the future!

Together with Roel Lefever, I stayed one month at UTFSM in Valparaíso, working with Raquel Pezoa on machine learning (ML) techniques for spectral analysis. We focused on the prediction of spectra within pre-computed model grids from the PoWR stellar atmosphere code and explored various emulation methods to improve both accuracy and efficiency. The collaboration was very enriching, allowing me to deepen my understanding of ML applications. I am looking forward to continue working together and expanding on this work in the future.

Outside of work, I enjoyed discovering the vibrant city of Valparaíso with its many hills, colourful street art, and unique atmosphere. We also had the chance to explore the surroundings, including trips to Viña del Mar, Santiago de Chile and the Andes. Overall, I am super grateful for the opportunity and look forward to future scientific exchange.

From the 3rd of March to the 2nd of April, I have stayed in Valparaíso (Chile) to directly collaborate with Prof. Raquel Pezoa at the Universidad Técnica Federico Santa María (UTFSM). There, together with Elisa Schösser, we worked on a project to apply machine learning algorithms to the emulation of stellar spectra. More specifically, we applied these algorithms to O-type spectra where we used the Potsdam Wolf-Rayet (PoWR) code and the existing O-star model grids. With Raquel’s crucial input and knowledge, we made great improvements in several key sections of our project: dimension reduction, selection of efficient regression algorithms (e.g. random forest, gradient boosting, Bayesian neural networks, …), optimisation of hyperparameters, and so forth.

Aside from the charming campus of UTFSM Valparaíso, where Raquel made sure we felt at home, I also had the chance of seeing Chile outside of my scientific work. The city of Valparaíso certainly earns its name as the Jewel of the Pacific, with a multitude of gorgeous places to visit. Travelling to other parts of Chile and seeing some amazing places, like the natural parks on the Isla de Chiloé and the Embalse El Yeso in the Andes close to Santiago, were experiences that only confirm how beautiful Chile is. Getting the opportunity to work in Chile during the Secondment was very enriching to me, both as a scientist and on a personal level.

During my one-and-a-half-month stay at the Faculty of Astronomy of the National University of La Plata and the Institute of Astrophysics of La Plata (IALP), I had the opportunity to collaborate closely with their research teams on two key objectives.

The first was to work with Roberto Gamen and his team to learn and apply techniques for generating orbital solutions by combining photometry and spectroscopy. The second was to initiate coordination with the La Plata team for the quantitative spectroscopic analysis of a sample of SB2 stars that the IACOB project intends to start exploiting.

For the first objective, Roberto’s group was incredibly helpful. Tomás Ansín guided us through orbital analysis using PHOEBE II, while Gabriel Ferrero provided valuable insights into the usefulness of available photometric data for my personal project, MUDEHaR. Working alongside Roberto, we analyzed ten binary systems and derived new orbital solutions for six. After an extensive literature review, the paper is now in an advanced stage of writing.

For the second objective—conducting quantitative spectroscopic analysis (QSA) on the SB2 systems now proritized by IACOB—we established a strong synergy with Roberto’s team. Cristina Putkuri led the disentangling process and individual analysis, while Jordi Eguiren focused on modeling the combined spectra and fitting them. We are now halfway through our target sample, and the manuscript for the final paper is already started. These results will be crucial for testing theoretical models, a topic I had the chance to discuss in a fascinating conversation with Professor Omar Benvenuto.

Additionally, the public release of MUDEHaR’s data coincided perfectly with my stay, allowing me to present a seminar on the project to the faculty personnel. This sparked an engaging discussion with Lydia Cidale’s group about potential applications of the dataset.

Beyond the academic collaboration, my time in La Plata was enriched by the warm hospitality of the team, with many opportunities to enjoy social gatherings and explore different parts of the country. A fantastic experience!

During my one-month secondment in the Canary Islands, I had the opportunity to spend time in La Palma and at the IAC in Tenerife.

While in La Palma, I worked closely with my colleague Cecilia Fariña to develop a proposal for observing stellar clusters using the WEAVE instrument once it becomes operational. This project, in collaboration with Andrea Ahumada, Yael Aidelman, and Martina Tapia, aims to explore how Be stars influence the integrated spectrum of intermediate-age open clusters. Cecilia kindly organized a visit to the Roque de los Muchachos site, where we had the incredible opportunity to see both the William Herschel Telescope, where WEAVE is installed, and the Gran Telescopio de Canarias. It was great to see the instrument up close and assess its strengths and challenges. I appreciated the breathtaking landscapes of the island very much! During this visit, I also gave a seminar to a group mainly composed of students and instrumentation experts.

At the IAC, I continued refining the scientific justification for our proposal and had the opportunity to interact with Sergio Simón-Díaz about the OCEANS collaboration. As the first person from OCEANS to visit the IAC, there was much to learn, especially regarding the paperwork and bureaucratic processes. Fortunately, we also had time to discuss our own research and explore potential future synergies. I participated in a group meeting with Sergio's team, as well as with another OCEANS group led by Montserrat Armas Padilla and Teodoro Muñoz Darias, who are working on compact objects. Coming from a small lab like the one at UNRN, it was incredibly inspiring to be immersed in such a vibrant and collaborative environment, attending seminars and contributing to discussions.

I also had the chance to explore the beauty of Tenerife beyond the magnificent San Cristóbal de la Laguna, where the IAC is located, including an unforgettable visit to El Teide, where I experienced its stunning volcanic landscapes.

It was a fantastic and enriching experience!