I spent six weeks at IALP–UNLP in La Plata, where I worked closely with the local group led by prof. Roberto Gamen. During the first weeks, I presented my research to several audiences: a small group of Prof. Gamen’s collaborators, a broader massive-star community at the institute, and finally in an open talk aimed also to B.Sc. students. My goal was to explore potential collaborations beyond the OCEANS network. These activities filled the first two weeks and led to promising outcomes, including the interest of Prof. Omar Benvenuto - facilitated by Prof. Gamen and Prof. Gabriel Ferrero. Together we initiated an interesting scientific contact that we plan to develop further in the future.

During the following weeks, I worked closely with Prof. Gamen. We cross-matched the O-type main-sequence stars in the IACOB database with binarity information from OWN, MONOS, and other bibliographical sources. We also examined several new systems using the available observations. Within the framework of my ongoing project, we combined this information with stellar parameters to investigate the evolutionary history of these systems. The results encouraged us to continue developing this line of research, with the aim of preparing a publication and requesting new observations to strengthen our conclusions.

But my visit to La Plata was more than working. During these weeks, I participated in the daily life of the institute. I joined the group’s biweekly meetings, shared lunchtime with colleagues, and enjoyed several moments of spare time together. My interest in the history and culture of the places I visit -and in the connections between Spain and Latin America, which creates strong bonds people- also encouraged me to explore other cities. Besides La Plata, I visited Buenos Aires, Montevideo (Uruguay), and Córdoba. I shared parts of the local culture, such as tango and milongas with my office mate, and an asado with the group. I also had the chance to visit La Plata Observatory, one of the oldest in South America, and even took part in observations with a nineteenth-century telescope. Finally, during Museos a la luz de la Luna, an outreach activity organized by UNLP, I had the opportunity to see a first edition of Newton’s Philosophiæ Naturalis Principia Mathematica.

Thanks to the spirit of OCEANS, this experience is neither the beginning nor the end of anything. In La Plata I reconnected with colleagues I had previously met during their visits to Tenerife, and with others I will meet again in conferences, future secondments, etc. The opportunity to work beyond European borders strengthened not only my professional network but also my personal life. I returned with new ideas, deeper knowledge, and -which is more important- new names and shared moments.

During these first secondments, we conducted several productive discussions regarding our mutual collaboration betweeen the groups of X-ray binaries in the UNLP and the IAC. 

Specifically, we have worked on the data reduction and preliminary analysis of a photometric campaign conducted with the Jorge Sahade Telescope at CASLEO observatory in San Juan, Argentina. During that campaign, we performed observations of a black hole X-ray binary along several nights covering its full orbital period during quiescence.

In the coming months, we will continue our collaboration performing the light-curve modelling to infer important orbital, geometrical and physical parameters of the source, including stellar masses, inclination, and properties of the accretion disk. 

In addition, we have worked together in the submission of proposals to observe X-ray binaries both in the optical and near infrared, as well as in the X-ray band with instruments like Gemini, and XMM-Newton.  

Moreover, during this secondment, Dr. García offered a Colloquium at the IAC that has been recorded and published in the online repository of IAC Talks (link to the video is here). The Seminar was entitled "Delving into the state transition in X-ray binaries: an spectral timing perspective" and was attended in person by several members of the IAC.

During the last week of the stay, we had the opportunity to visit the IAC observatory at Izaña. It was a remarkable chance to share the starry night together, and get to know about the different instruments that populate the elevated terrains of Tenerife, at the base of the Teide volcano. 

The excellent scientific discussions were also balanced with warm social activities, as dinners and visits to different wonderful places on the Tenerife island, which helped to reinforce our mutual relationship that will grow and enhance thanks to this OCEANS project. 

From September 29th to November 22nd, I carried out a research stay at the Astronomical Institute of the Czech Academy of Sciences (ASU) in Ondřejov, Czech Republic. During this period, I worked under the supervision of Dr. Michaela Kraus, and in collaboration with Dr. Olga Maryeva. My work focused on analyzing observational data obtained with the 6-m BTA telescope for two Herbig Ae/Be objects, using the SCORPIO-2 instrument in both Fabry–Perot interferometric and long-slit spectroscopic modes.

The Fabry–Perot data allowed me to study the morphology, intensity distribution, and kinematics of the nebulae surrounding the targets through Hα emission, leading to the construction of velocity fields, channel maps, and moment maps. In parallel, I analyzed long-slit spectra for both objects, obtained with the VPHG1200@540 grism, to investigate their spectral structure, emission-line profiles, and physical conditions. Together, these datasets provide complementary spatial and spectral information, helping to characterize the circumstellar environments of the two Herbig Ae/Be stars.

Additionally, I collaborated with Dr. Michalis Kourniotis on the development of a new project aimed at studying LBV stars with shell-like envelopes. This work involves defining the target sample and designing the observational strategy in preparation for a future observing proposal to the Gemini Observatory.

During my stay, I also participated actively in institute activities, including group meetings, seminars, the Joint Journal Club, and the outreach event Researchers’ Night, held on September 26th, 2025.

I also had the opportunity to give a seminar, where I briefly presented both my ongoing research and the project developed during my stay. These activities provided valuable opportunities for scientific discussion, collaboration, and engagement with the public.

Outside the academic activities, I also greatly enjoyed the opportunity to explore Ondřejov, Prague, and their surrounding areas. Discovering the local culture, architecture, and history enriched my experience beyond the scientific work. These experiences made the stay not only academically valuable but also personally memorable.

Overall, this research stay was an extremely enriching experience, both scientifically and personally. I am very grateful for the opportunity to work at ASU Ondřejov and for the support received throughout my stay. I look forward to continuing the collaborations initiated during this period and to further strengthening the scientific exchange fostered by this visit.

During my stay, I collaborated with Dr. Julieta Sánchez on three different projects. We continued an ongoing collaboration on the study of the photometric and spectroscopic variability of the BSG HD 41117, along with colleagues from the Instituto de Astrofísica de La Plata in Argentina. This work is currently being prepared for submission to Astronomy & Astrophysics. I also began collaborating on one of Dr. Sánchez’s papers, which focuses on the application of the EEMD technique and its effectiveness in separating the red-noise component present in real astronomical data, such as those obtained with TESS. For this purpose, I started learning about Gaussian processes and EEMD methods. This work is also being prepared for publication. Finally, Dr. Sánchez joined one of my ongoing PhD-thesis projects, which involves designing an experimental simulation to evaluate the contribution of Rossby waves to the observed red-noise profile in OB-type stars.

I also had numerous discussions on asteroseismology with Dr. Michalis Kourniotis, particularly regarding current tools for distinguishing genuine periodicities in TESS data and statistical methods for evaluating this behavior in large samples of B-type supergiant stars. We plan to continue this collaboration during Dr. Kourniotis’s visit to the Institute of Astrophysics of La Plata in January 2026.

In October, I also participated in the department’s Journal Club, where I presented the paper “Stochastic low-frequency variability of 50 massive stars in the Cygnus OB associations and the Small Magellanic Cloud” by Pedersen & Bildsten (2025). This was a very enriching experience, as it allowed me to interact with many colleagues of the stellar department. Moreover, I participated in the outreach activity Researchers’ Night organized at ASU on September 26th, 2025.

Beyond the academic activities, this secondment also allowed me to explore the Czech Republic and fall in love with its culture and the kindness of its people.

I sincerely thank all the members of the OCEANS project who made this secondment possible for me and all my colleagues at the Institute for their patience and constant kindness. They made my stay very pleasant. I hope to see you all again!

I spent two months in Tenerife with the IAC's Massive Stars group, who shared their knowledge and techniques with me. This was extremely beneficial for my ongoing studies. During this time, I also presented my current work and preliminary results. Sergio Simón-Díaz introduced me to everyone in the group, and I was pleased to have the opportunity to speak to them all. I met with him several times to discuss various aspects of massive star research, and these meetings provided valuable insight into their approaches.

Over the weeks, I participated in the group's meetings, during which I learned about the role of each group member, their working methods, and how they organise their observation campaigns. This gave me a good overview of their dynamics and possible future contributions.

I had some meetings with Gonzalo Holgado, whom I had already met during his visit to the UNLP at the beginning of the year. He gave me a detailed explanation of how IACOB-BROAD and IACOB-GBAT work. These are tools that I could naturally implement in future work and which are excellent candidates for use in collaborative research projects.

I also discussed some aspects of using and interpreting PHOEBE results with Michael Abdul-Masih. PHOEBE is core software for my thesis and Michael is part of the development team, so these technical discussions were particularly valuable. He also introduced me to his SPAMMS code, which combines PHOEBE with FASTWIND models.

Meanwhile, I continued working on my thesis and met doctoral students who introduced me to day-to-day life at the IAC, as well as activities outside the academic sphere. I also had the opportunity to visit the observatory in Izaña, where we observed the fascinating night sky of Tenerife and the impressive instruments located there.

This was my first experience abroad and I am very grateful for it, as I found myself in a spectacular place surrounded by nice people who were always willing to share their experiences. I am particularly grateful to the OCEANS project for making this visit possible.

From July 29th to September 18th, I carried out a research stay at the Nicolaus Copernicus Astronomical Center (CAMK) in Warsaw, Poland, under the supervision of Dr. Bogumił Pilecki and in collaboration with Monica Taormina. The main focus of this visit was to strengthen my training in the physical modeling of eclipsing binary systems and to explore the use of machine learning techniques to characterize massive stars in the Magellanic Clouds.

This work contributes to the broader goals of the OCEANS project, which seeks to deepen our understanding of the evolution and nature of massive binary stars.

Beyond research activities, I also had the chance to experience Poland’s cultural and natural richness. I visited both Warsaw and Krakow, exploring their historic landmarks, museums, and green areas, and I enjoyed tasting traditional Polish dishes and the wide variety of seasonal fruits.

Overall, this secondment was an extremely enriching experience, both scientifically and personally. I am very grateful for this opportunity and look forward to continuing the scientific exchange fostered by the OCEANS project.

I had the privilege of working at the Instituto de Astrofísica de Canarias (IAC) for two months, from 28 May to 30 June 2025, in an enriching collaboration with Sergio Simón-Díaz, Gonzalo Holgado, Artemio Herrero, and the entire massive stars research group based in Tenerife.

Our work focused primarily on several topics in collaboration with Sergio. The main project involved organizing and completing a study we began a couple of years ago on the massive binary system iota Orionis Aa. We had ample time to discuss the structure of the available data, carry out various calculations, develop the necessary scripts to process, analyze, model, and visualize the spectroscopic and photometric data, and begin drafting the upcoming paper. It was particularly important for me to gain a deeper understanding of how the IACOB-GBAT software performs specific calculations and how to properly estimate the associated uncertainties.

Another line of work, more exploratory in nature, involved analyzing the harmonic content of radial velocity measurements for several massive stars, some of which are binaries and others not. This was a new step toward improving the techniques we currently use to characterize both orbital motion and pulsational variability in such stars, while accounting for potential observational biases.

I greatly benefited from participating in the daily life of the research group—learning how they organize their work and weekly meetings, gaining a better understanding of their research topics, scientific goals, and the challenges they face. I was kindly invited to give an open talk on the research being conducted in La Plata on massive stars, particularly in the main areas I’m currently involved in.

One important outcome of my stay in Tenerife was realizing that new, previously unconsidered collaborations are possible. In fact, an exciting opportunity emerged for collaboration with researchers working on interferometry with MAGIC. Additionally, we took steps to strengthen interactions with a group in La Plata focused on stellar evolution modeling.

While in Tenerife, I continued to attend to several responsibilities from La Plata. This made it especially enriching to have in-depth conversations with Sergio about astronomy education and supporting the professional development of students and postdocs in different countries. It was interesting to find that many challenges are shared, and we exchanged views and strategies on how to address them.

A very special moment was the visit to the Roque de los Muchachos on La Palma, where I had the chance to see (and touch!) the Gran Telescopio Canarias, the Isaac Newton Telescope, and the Telescopio Nazionale Galileo. Each of these instruments is a remarkable piece of technology, scientific history, and astronomical achievement, and getting to know them in person was incredibly exciting.

During weekends and holidays, I had the chance to explore the local culture. As a Uruguayan, it was particularly moving to learn more about the roots of my country —and many others in Latin America— and their historical connection with the Canarian people. It was also wonderful to discover, even briefly, these beautiful islands —their landscapes, geography, unique weather, and fascinating geology.

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.

From 23 February to 16 May, I visited the Academy of Sciences of the Czech Republic (ASU) in Ondrejov. During my stay, I worked with Dr. Pavel Jachym and the Czech ALMA Regional Centre (ARC) in Prague, deepening my understanding of ALMA and preparing an observational proposal to study a massive young stellar object of great interest. I also attended the Pre-Cycle 12 ALMA Workshop held at the Astronomical Institute of ASU, in Spořilov, Prague. The proposal was successfully submitted for Cycle 12.

Additionally, I collaborated with Dr. Michalis Kourniotis assessing the possibility of preparing a proposal for observing with the Gemini South telescope for future calls. I also had the privilege of visiting the Perek 2-m telescope in Ondrejov, the largest optical telescope in the Czech Republic, and join Dr. Julieta Sanchez during some of her observation nights.

Furthermore, I actively participated in group meetings and discussions at both the Ondrejov and Prague institutes, as well as in the Joint Journal Club between both groups. 

Outside of work, I enjoyed exploring the surrounding nature through hiking trails in Ondřejov, witnessing the beautiful transition from winter to spring, and experiencing both snowy landscapes and blooming forests.

I also spent time in Prague, discovering its stunning architecture and taking part in local traditional celebrations.

Getting the opportunity to work in the Czech Republic during the secondment was very enriching to me, both as a scientist and on a personal level, and I am truly grateful for the experience. I look forward to future scientific exchange.

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!