The Institute of Cosmos Sciences of the University of Barcelona (ICCUB) will present PulSensing Technologies, a new spin-off specializing in the design of advanced custom microelectronics (ASICs) and ultra-fast, low-power readout systems for particle and radiation detection, at SOMMa Connect 2026. 

This event, organized by the Alianza de Centros de Excelencia Severo Ochoa y Unidades de Excelencia María de Maeztu (SOMMa), together with the Center for Genomic Regulation (CRG), will host scientific leaders, companies, investors, entrepreneurs and representatives of public institutions to learn first-hand some of the technologies and projects with the greatest potential arising from the excellence research that is being developed in Spain, as well as to explore new opportunities for collaboration, investment and knowledge transfer. 

PulSensing Technologies will be presented during the Investment Pitch Session within the DeepTech & Advanced Engineering track on Tuesday, 22 September, at 3:00 PM, where the company will present its technology and growth roadmap to investors, industry representatives and innovation stakeholders. 

SOMMa Connect was born with the objective of bringing the scientific capacity of its member institutions closer to the business and innovation ecosystem, creating a space where science, industry, investment and administrations can meet, share needs and identify opportunities to transform new knowledge and technologies into solutions with economic and social impact. 

 The 2026 edition will bring together representatives of some of the main institutions that promote and finance innovation in Spain and Europe, including the Center for Technological Development and Innovation (CDTI), the Ministry of Science, Innovation and Universities, the European Innovation Council (EIC) and the European Investment Fund (EIF), along with investors, companies and organizations linked to the transfer and innovation ecosystem. 
 

PulSensing Technologies 

The company stems from the expertise in high-precision scientific instrumentation developed at the ICCUB, with the aim of transferring this knowledge to industrial sectors, primarily high-resolution medical imaging (such as Positron Emission Tomography, PET/SPECT), although its technology is also applicable to other cutting-edge fields like high-energy physics, quantum communications, and space instrumentation. 

Currently, global access to advanced diagnostics via PET scanners is severely limited by the cost and complexity of traditional equipment. PulSensing’s technology overcomes this bottleneck through integrated chips capable of processing detector signals with extremely high temporal precision within a fraction of the usual footprint, drastically reducing both energy consumption and scanner manufacturing costs. This paves the way for a new generation of medical equipment that is more compact and accessible, offering unprecedented capabilities for the early detection of diseases such as cancer. 

PulSensing stands out for its efficiency and economic viability. In its first year of operation, the company has been entirely self-financed (bootstrapping), generating over €200,000 in commercial revenue through projects and technological developments for international clients and partners.  

Building on this solid foundation, PulSensing is now steering its growth toward the co-development of industrial pilot projects with medical instrumentation manufacturers (OEMs) and active participation in major European R&D consortia (such as the Chips Joint Undertaking and the EIC Accelerator), thereby consolidating the University of Barcelona's research leadership within the international industrial and technological landscape. 
 

A highly experienced team 

PulSensing is supported by a highly specialized team:  

• Óscar de la Torre, CEO: physicist, engineer of the ICCUB Technology unit and MBA, with experience in start-ups and seven years in ASIC quality control. 

• Daniel Guberman, CTO: PhD in Physics, engineer of the ICCUB Technology with more than eight years in R&D of PET detectors and five years in technical management. 

• David Gascón, UB professor and director of the ICCUB Technology Unit, with more than 25 years of experience in ASIC R&D. 

• Andreu Sanuy, PhD in Elecronics, engineer of the ICCUB Technology expert in PCB design and ASIC packaging. 

• Joan Mauricio, PhD in Elecronics, engineer of the ICCUB Technology, ASIC design specialist and software/firmware developer. 

PulSensing Technologies represents a new example of the transfer of frontier research developed at the ICCUB into market-oriented technological solutions with potential societal impact. 

The Institute of Cosmos Sciences of the University of Barcelona (ICCUB) has participated in the development of CTAO and in the conception of these four large telescopes. Four of its researchers, Josep Maria Paredes, Marc Ribó, David Gascón and Pol Bordas, have been involved in documenting the process, from the initial design phase through technological development and the scientific goals of the project.

The inauguration of the four telescopes marks a fundamental milestone in the development of CTAO, as it completes the construction of all the large-sized telescopes planned for CTAO-North. The first telescope, LST-1, was inaugurated in 2018 and has since been undergoing commissioning under the responsibility of the LST Collaboration. It is now joined by three additional large-sized telescopes, which will eventually be accompanied by Medium-Sized Telescopes (MSTs).
 

However, the work does not end with this milestone. The LSTs must undergo an extensive commissioning phase carried out by the LST Collaboration before being formally accepted by the CTAO Central Organization (CTAO ERIC) and beginning operations and the exploitation of so-called "early science". LST-1 is expected to be the first telescope accepted, during 2027, bringing closer the start of the Observatory's major scientific output.
 

The design and construction of these telescopes has been carried out by the LST Collaboration, which has acted as an in-kind contributor to CTAO ERIC and has complied with strict technical requirements.

Spain's key role in the project

Spain plays a strategic and fundamental role in CTAO. Together with Japan, it is the country contributing the most to the development of the LSTs, accounting for 32% of the project. This, together with its role as host country of CTAO-North, gives the Spanish scientific community privileged access to observing time at these facilities and makes Spain an important hub for talent attraction and scientific production.
 

Under the name CTAO-Spain, the institutions in Spain dedicated to hardware, software and scientific activities for the Observatory are grouped together. These institutions, located in Andalusia, the Canary Islands, Catalonia and Madrid, are:
 

• Institute of Cosmos Sciences of the University of Barcelona (ICCUB)
• Institute of Space Studies of Catalonia (IEEC)
• Centre for Energy, Environmental and Technological Research (CIEMAT)
• Institute of Astrophysics of Andalusia (IAA-CSIC)
• Institute of Astrophysics of the Canary Islands (IAC)
• Institute of Space Sciences (ICE-CSIC)
• Institute for High Energy Physics (IFAE)
• University of Alcalá (UAH)
• Complutense University of Madrid (UCM)
• University of Jaén (UJA)

 
In addition to the scientific and technological contribution of Spanish teams within the LST Collaboration, the industrial sector also plays an important role. Spanish industry has manufactured key telescope components, including motion systems, camera mechanics and infrastructure.

The Project Timeline and Spanish Participation
 

Professor Josep Maria Paredes (ICCUB-IEEC) traces the origins of the CTAO project back more than twenty years. The initial need was to overcome the sensitivity limitations of earlier instruments such as the H.E.S.S., MAGIC and VERITAS Cherenkov telescopes, as well as the earlier HEGRA experiment.
 

Paredes explains: "The scientific and technological experience acquired by Spanish groups through participation in these previous collaborations served as the basis for their current technical contribution to CTAO and, specifically, to the LST project. Hosting CTAO-North in the Canary Islands guarantees the Spanish scientific community 10% of the observing time, a factor that will enable the execution of its own projects and serve as motivation for new generations of researchers."

From International Collaborations to an Open Observatory
 

Professor Marc Ribó (ICCUB-IEEC) took part in the first CTAO science-case meeting in 2006 and has formally led ICCUB's contribution to CTAO since 2010. CTAO represents a paradigm shift because, unlike previous instruments operating in the same energy range, it will function as an observatory open to the scientific community.
 

Ribó explains: "Previous Cherenkov telescopes have been used within the framework of large international collaborations that operated in a relatively closed manner with respect to the wider scientific community. The large number of scientific cases that CTAO will enable, as well as the major financial investment required, have led CTAO to be conceived as an observatory open to the international scientific community. While some observations of strategic scientific targets will be carried out by the CTAO Consortium, there will also be numerous projects led by independent teams that will likely address scientific questions not previously explored."

Technological Development: Electronics and the Data Filtering System
 

David Gascón, Director of the ICCUB Technology Unit and member of the IEEC, has been working in the LST engineering area since 2008. His work, together with that of his team, has focused on designing specific camera components, including three integrated circuits developed to measure photon signals at high speed.
 

In collaboration with other Spanish institutions, the team participated in the development of the data filtering system. This electronic system operates in real time, analysing millions of images per second to filter out spurious or background information, such as ambient light or other stars, and identify patterns corresponding to gamma rays. As Gascón explains, this electronics system is what makes it possible to isolate and identify signals of interest within fractions of a nanosecond.

Scientific Goals: Studying Transient Events
 

Researcher and professor Pol Bordas (ICCUB-IEEC), who has co-led the scientific programme of LST-1 over the last two years, explains how these telescopes operate. Bordas describes how the LSTs use the Earth's atmosphere as part of the detector: when high-energy photons strike the atmosphere, they generate particle cascades that produce Cherenkov light, a very fast bluish light detected by the telescopes on the ground.
 

The LSTs, equipped with mirrors 23 metres in diameter, are designed to detect these emissions in the Observatory's lowest energy range. This capability will be used to study transient phenomena, defined as rapid and not necessarily periodic events. Among the objects of study mentioned by the researcher are gamma-ray bursts (GRBs), fast radio bursts (FRBs), and the possible gamma-ray electromagnetic counterpart associated with gravitational waves.
 

"The future operation of the LSTs as part of CTAO will serve both to confirm current physical predictions and, potentially, to detect new astrophysical events not documented to date," explains Bordas.

About CTAO
 

CTAO will be the world's largest and most powerful gamma-ray astronomy observatory. Its unprecedented precision and broad energy range (from 20 GeV to 300 TeV) will help answer some of the most exciting questions in astrophysics, grouped into three main themes: understanding the origin and role of cosmic relativistic particles; investigating extreme environments such as black holes and neutron stars; and exploring the frontiers of physics in the search for dark matter and deviations from Einstein's theory of relativity. In addition, thanks to its enhanced performance, CTAO will play a key role in the coming decades in the fields of multi-messenger and multi-wavelength astronomy, providing crucial information about gamma rays in the most extreme environments.
 

To cover its broad energy range, CTAO will use three types of telescopes: Large-Sized Telescopes (LSTs), Medium-Sized Telescopes (MSTs) and Small-Sized Telescopes (SSTs). More than sixty telescopes will be distributed between two sites: CTAO-North, in the Northern Hemisphere, located at the Roque de los Muchachos Observatory of the Institute of Astrophysics of the Canary Islands (IAC) on La Palma; and CTAO-South, in the Southern Hemisphere, at the European Southern Observatory's Paranal Observatory in Chile's Atacama Desert. The CTAO headquarters are hosted by Italy's National Institute for Astrophysics (INAF) in Bologna and by the Science Data Management Centre (SDMC), located on the campus of the German Electron Synchrotron (DESY) in Zeuthen.
 

CTAO is a big-data project. It will generate hundreds of petabytes (PB) of data per year, approximately 12 PB after compression. In line with its commitment to open science, CTAO will be the first ground-based gamma-ray observatory to operate as an open, proposal-driven observatory, providing public access to high-level scientific data and software products.
 

The CTAO Central Organization is responsible for constructing and operating the Observatory. It manages the four CTAO sites (the headquarters in Bologna, the SDMC in Zeuthen, and the two telescope arrays in La Palma and Atacama) and works closely with partner groups worldwide on Observatory development. Its main partners include the In-Kind Contribution Collaborations (IKCs), which are developing essential hardware and software, as well as the CTAO Consortium, an international group of researchers dedicated to the scientific exploitation of the Observatory. Among the IKCs is the CTAO LST Collaboration, responsible for developing the LSTs.
 

The members of CTAO ERIC are Austria, Croatia, Czech Republic, France, Germany, Italy, Poland, Slovenia, Spain, Switzerland and the European Southern Observatory. The Netherlands also participates in CTAO ERIC as an observer. Other countries, including Australia, Brazil, Japan, South Africa and the United States, are strategic partners or third parties.

About the LSTs
 

The LSTs are one of the three telescope types that CTAO will use to cover its broad energy range from 20 GeV to 300 TeV. When gamma rays interact with the Earth's atmosphere, they generate particle cascades that produce Cherenkov light. Because lower-energy gamma rays generate only very small amounts of this light, telescopes with large collecting areas are required to detect it. The LST, with its 23-metre-diameter reflector, will provide CTAO's unique sensitivity in the low-energy range (between 20 and 150 GeV).
 

Despite standing 45 metres high and weighing 100 tonnes, each LST can be repositioned in less than twenty seconds to point to any location in the sky. Both this rapid repositioning capability and the low energy threshold of the LSTs are essential for CTAO studies of galactic transient phenomena, high-redshift active galactic nuclei and gamma-ray bursts.
 

The CTAO LST Collaboration is responsible for designing and building these telescopes. It consists of more than five hundred scientists and engineers from 25 institutions across eleven countries: Brazil, Bulgaria, Croatia, Czech Republic, France, Germany, Italy, Japan, Poland, Spain and Switzerland.
 

The LST Collaboration is making rapid progress at the CTAO-North site on La Palma. In 2018, the LST prototype, LST-1, was inaugurated and has been undergoing commissioning ever since. On 15 October 2026, the sub-array of four LSTs will be inaugurated in La Palma by the LST Collaboration, marking the completion of the construction of these telescopes at CTAO-North.

SOLARIS brings together astronomy and medicine to analyse, for the first time and on a large scale, how a total solar eclipse affects the human body, linking the phenomenon to our emotions and physiological responses. The project is promoted by the Ministry of Research and Universities of the Government of Catalonia, the Vall d'Hebron Research Institute (VHIR), and the Institute of Space Studies of Catalonia (IEEC), with researchers at the Institute of Cosmos Sciences of the University of Barcelona (ICCUB).

Get involved!

How can you take part? Becoming part of this pioneering research is very simple: all you need is a smartwatch that records your heart rate and the SOLARIS app installed on your mobile phone.

Download the app before 12 August and join the project!

• SOLARIS for Android
• SOLARIS for iOS

While you enjoy the spectacle of the eclipse, your device will collect valuable data that will allow research teams to generate new scientific knowledge collaboratively. Thank you!

More information

The Spanish Astronomical Society will hold its XVII Scientific Meeting from 13 to 17 July at the Tarragona Trade Fair and Conference Centre, in collaboration with astronomy research institutions in Catalonia (IEEC, ICE-CSIC, IFAE, ICCUB) and Catalan universities (UB, UAB, UPC, URV). 

The meeting, held every two years, will bring together more than 500 astronomy professionals, nearly one third of whom are predoctoral researchers. This edition will also include representation from the African Astronomical Society, which is the guest astronomical society in this edition. 

Comprehensive scientific programme 

The XVII Scientific Meeting of the SEA will serve as a key forum to discuss the main recent scientific and technological advances in astronomy and Spain’s prominent participation in them. 

The range of topics is broad and varied and includes, among others, the celebration of the tenth anniversary of the discovery of gravitational waves, a milestone that opened a new window for exploring the universe. Scientific results from the ESA’s Gaia and Euclid missions will also be presented—results that are transforming our understanding of our galaxy, the nature of dark matter, gravity and the accelerated expansion of the universe. It will also be shown how recent data obtained by the JWST observatory are forcing the scientific community to revise previous ideas about how the first galaxies formed and evolved. In addition, plenary sessions and the rest of the congress will include work demonstrating major advances in very-high-energy gamma-ray astrophysics, as well as how artificial intelligence and advanced language models are driving a revolution in astrophysics. 

Furthermore, Spanish astronomy has particularly good news this year, as ARRAKIHS, the first mission of the ESA Scientific Programme led by Spain, was approved last June and, with a launch planned for 2030, will also play a prominent role in this edition. 

Thematic symposia and special meetings 

The XVII Scientific Meeting of the SEA includes numerous thematic symposia and special meetings focused on specific research topics, tools or instruments. 

For example, there will be sessions discussing, step by step and thanks to observations such as those obtained by ALMA, about star formation, a process less uniform than previously thought, as well as the results of ongoing large spectroscopic surveys. There will also be discussion about the path toward first light of the ELT (Extremely Large Telescope), including scientific opportunities and technological contributions made by Spain to this telescope, which is expected to see first light by the end of this decade. Special sessions will also be devoted to key scientific results obtained with the 40-metre Yebes radio telescope, which celebrates its 50th anniversary this year, as well as presentations and discussions on the impact of the growing constellation of satellites in orbit and its effects on astronomical observation. 

Beyond astronomical research 

The XVII Scientific Meeting of the SEA will also address other relevant topics: the major work of the astronomical community around the trio of solar eclipses that Spain will experience in the coming years; the creation of new educational resources to bring astronomy closer to schools; highlighting the historical and current relationship between astronomy and culture; and new proposals to strengthen the scientific value of collaboration between professional and amateur astronomers in Spain. As in previous editions, the dynamic study of the impact of astronomical research on sustainability will also be addressed. 

During the meeting, the 7th Report on Human Resources in Astronomy and Astrophysics will also be presented, analysing the situation of astronomy professionals in Spain, with particular attention to early-career researchers and gender inequalities, among other aspects. 

As part of its commitment to work–life balance and promoting more inclusive scientific environments, the SEA will offer for the first time a childcare service for attendees who require it. This initiative aims to facilitate participation in the congress for researchers with family responsibilities, contributing to greater accessibility and diversity within the astronomical community. 

The SEA Scientific Meeting reaches out to Tarragona 

The trio of solar eclipses will be central to many of the outreach activities open to the general public organised alongside the scientific meeting. These initiatives complement the extensive programme organised by Tarragona City Council. In this context, participating astronomers will join this programme and share their specialised knowledge with the public. 

The public will be able to take part in a session dedicated to the Sun and solar physics combining expert lectures with live telescope observations. Another talk will explain the scientific keys to the total solar eclipse of 12 August 2026, along with recommendations for safe observation. The scheduled talks will also address the stellar origin of chemical elements essential for life and their connection to the evolution of the Universe, as well as how astronomy influenced urban planning in ancient Tarraco. 

The programme will be completed with a presentation of children’s and young adult science books about eclipses, stellar distances, the Milky Way and the astronomer Assumpció Català, with the aim of fostering scientific interest from an early age. This set of initiatives is designed to bring astronomy closer to all audiences and prepare for the major event of 12 August 2026, which will position Tarragona as a key location to experience the total solar eclipse.

Dr. Konstantin Karchev, researcher at the Institute of Cosmos Sciences of the University of Barcelona (ICCUB), has been awarded the 2025 PhD Prize by the International Astronomical Union (IAU) in the Division of Facilities, Technologies and Data Science. The award recognises outstanding doctoral research by early-career astronomers worldwide. 

Karchev’s thesis,“Supernova Cosmology for the 21st Century”, represents a major advance in the analysis of next-generation astronomical datasets. His work develops a novel simulation-based Bayesian framework for supernova cosmology, designed to address key limitations in traditional approaches, such as selection biases, simplified models, and uncertainties in photometric redshifts.  

The research combines high-performance GPU computing with innovative neural network architectures capable of handling complex and heterogeneous data. These tools are particularly relevant in the context of upcoming large-scale surveys, such as those from the Vera C. Rubin Observatory, enabling more robust and statistically rigorous cosmological inference.   

“I’m deeply honoured by this prestigious recognition for the efforts I, my doctoral advisor Roberto Trotta, and everyone I’ve collaborated with, put in towards this dissertation. I hope it inspires future scientists to think holistically about problems and solutions and to regard their academic work with pride and enjoyment”, says Konstantin Karchev.  

The IAU PhD Prize is awarded annually across its nine scientific divisions, each recognising the most impactful doctoral thesis in its field. In addition to Karchev, the 2025 awardees include Maximilian Häberle (Fundamental Astronomy), Kaleb Alho (Education, Outreach and Heritage), Yi Zhang (High Energy Phenomena), Hidetaka Kuniyoshi (Sun and Heliosphere), Bibiana Prinoth (Planetary Systems), Hila Glanz (Stars and Stellar Physics), Claude Cournoyer-Cloutier (Interstellar Matter) and Abigail Lee (Galaxies and Cosmology).  

All prize recipients will be invited to present their work at the IAU XXXIII General Assembly, to be held in Rome in August 2027. 

The most massive black holes in the Universe detected by the ripples they make in space time were not born directly from collapsing stars, according to a new study.

These cosmic giants instead build up through a series of repeated and extremely violent collision events in very densely populated star clusters, an international team of researchers argue.

Their study, led by Cardiff University, analysed version 4.0 of LIGO–Virgo–KAGRA’s Gravitational-Wave Transient Catalog (GWTC4), containing 153 sufficiently confident black hole merger detections.

The team wanted to test the idea that the heaviest black holes in GWTC-4 are second-generation objects, formed when earlier black holes merged and then merged again in the dense cores of star clusters, where stars can be packed up to a million times more tightly than in the Sun’s neighbourhood.

Their findings, published in Nature Astronomy, probe the origins of the heaviest black holes detected by their gravitational waves, revealing two distinct populations.

“Gravitational-wave astronomy is now doing more than counting black hole mergers,” explains lead author Fabio Antonini from Cardiff University’s School of Physics and Astronomy.  “It is starting to reveal how black holes grow, where they grow, and what that tells us about the lives and deaths of massive stars.”

“The ability to directly point to star clusters as the origin for these mergers, opens up the exciting possibility to use gravitational waves as completely new tool to learn about the formation and early evolution of dense star clusters that form in the early Universe,” says co-author Mark Gieles, ICREA research professor at the Institute of Cosmos Sciences of the University of Barcelona (ICCUB) and the Institute of Space Studies of Catalonia (IEEC).

In the gravitational-wave data, the team identified:

• A lower-mass population consistent with ordinary stellar collapse
• A higher-mass population whose spins appear exactly like those expected if those black holes were formed by repeatedly merging with other black holes inside crowded groups of stars, rather than being born directly from single stars

“What surprised us most was how clearly the high-mass black holes stand out as a separate population,” recalls co-author Isobel Romero-Shaw, Ernest Rutherford Fellow at Cardiff University. 

“Unlike the lower-mass systems we analysed, which were generally slowly-spinning, the higher-mass systems are consistent with having more rapid spins, oriented in seemingly random directions. This is the exact signature you would expect if black holes were repeatedly merging in dense star clusters.

“That makes the cluster origin much more compelling than it was with earlier catalogues.”

The study also provides the strongest evidence yet for a “mass gap”, where extremely massive stars explode catastrophically rather than collapsing into black holes.

The long-predicted theory describes a forbidden mass range for black holes made directly from stars, where very massive stars are expected to be disrupted before they can form black holes.

The team pinpoints this range in a population of stellar-origin black holes 45 times the mass of the Sun and above.

Dr Antonini said: “In our study we find evidence for the long-predicted pair-instability mass gap — a range of masses where stars are not expected to leave behind black holes at all. Gravitational-wave detectors have successfully found black holes that appear to sit in or near that gap, which we identify at around 45 solar masses.

“So, the key question now is are these black holes telling us that our models of stellar evolution are wrong, or are they being made in another way?

“The biggest black holes in the current sample seem to be telling us about cluster dynamics, not just stellar evolution.

“Above about 45 solar masses the spin distribution changes in a way that is hard to explain with normal stellar binaries alone but is naturally explained if these black holes have already been through earlier mergers in dense clusters.”

The team also used this transition to shed light on an important nuclear reaction involved in helium burning inside massive stars.

“In the future, gravitational-wave data may help scientists study nuclear physics, because the mass limit set by pair instability depends on the nuclear reactions taking place in the cores of massive stars,” added co-author Fani Dosopoulou, a research associate at Cardiff University.

Reference

Antonini, F., et al. Gravitational waves reveal the pair-instability mass gap and constrain nuclear burning in massive stars. Nature Astronomy (2026). https://doi.org/10.1038/s41550-026-02847-0

The documentary "Gaia: de casa nostra a l'Univers", produced by Big Van Ciència with the support of a grant from the Catalan Foundation for Research and Innovation (FCRI), highlights Catalonia’s key role in one of the most ambitious scientific missions in recent history: the Gaia mission of the European Space Agency (ESA).

Thanks to Gaia, humanity has been able to map nearly two billion stars in the Milky Way with unprecedented precision. A fundamental part of this success has been developed in Catalonia, with teams from the University of Barcelona (UB), the Institute of Space Studies of Catalonia (IEEC), and the Institute of Cosmos Sciences of the University of Barcelona (ICCUB) leading scientific contributions of top international level.

The premiere event will feature Teresa Sanchis, Director General for Research of the Government of Catalonia; Helena González, Director of Big Van Ciència; Xavier Luri, Full Professor in the Department of Quantum Physics and Astrophysics at the University of Barcelona, Director of the IEEC, and Principal Investigator of Gaia in Spain; Mercè Pallàs, Deputy for Coordination with UB Research Institutes; Maria Terrades, Director of the Barcelona Science Park; and Miquel Gómez, Director of the FCRI.

The event will combine institutional speeches, a screening of the documentary (35 minutes), and a science outreach show featuring humor and improvisation by Big Van Ciència, which will allow the audience to interact live with researchers from the Gaia mission.

The voice of Catalan science

“Gaia: de casa nostra a l'Univers” is not just a scientific documentary: it is a story about how research carried out in Catalonia is helping to transform global knowledge of our galaxy.

With more than 16,000 scientific publications derived from its data, Gaia has become a key tool for understanding the structure, origin, and evolution of the Milky Way. This documentary brings this scientific revolution closer to the general public, using an approachable and human tone, with touches of humor.

In the Gaia mission—the most ambitious project of the ESA to study the history and structure of the Milky Way—a team of astronomers and engineers from the Department of Quantum Physics and Astrophysics of the University of Barcelona, the ICCUB, and the IEEC has taken part since the very beginning, under the initial leadership of Professor Jordi Torra. Launched in 2013, the Gaia satellite has transformed our understanding of the cosmos through detailed stellar cartography of the positions, distances, motions, and properties of nearly two billion stars and other celestial objects.

Professor Xavier Luri highlights that “the UB Gaia team has worked on the mission since its beginnings, around 1997.” “Since then, it has taken part in all phases, from defining the scientific case and industrial design to data processing and scientific exploitation,” he continues. “Now, although Gaia has finished its observations, several years of work remain to fully process all the data collected during this period and to publish two additional data releases (DR4 and DR5),” the researcher concludes.

Black holes are often depicted as cosmic vacuum cleaners, but they are also powerful engines capable of launching jets: extremely fast streams of matter and energy shot out at nearly the speed of light. These jets strongly influence their surroundings, from nearby stars to entire galaxies. Yet one key question has remained unanswered: how powerful are these jets at any given moment?

A study published in Nature Astronomy has now achieved this long‑sought measurement by observing a jet that is quite literally bent sideways, and changing direction along the orbit.

The research focuses on the microquasar Cygnus X‑1, one of the most famous black holes in our Galaxy, located about 7,000 light‑years from Earth. The black hole orbits a massive, hot companion star that produces a powerful stellar wind — a constant stream of gas moving at thousands of kilometres per second.

Using almost 20 years of ultra‑sharp radio observations, the team discovered that this stellar wind pushes against the black hole’s jet, bending it as it travels through space. By modelling this interaction along the orbit, the researchers were able to directly calculate the jet’s power.

“The stellar wind acts like a natural probe,” explains Valentí Bosch‑Ramon, researcher at the Institute of Cosmos Sciences of the University of Barcelona (ICCUB) and co‑author of the study. “By measuring how much the jet bends and changes direction with time, we can determine how strong it really is.”

Reading a jet from its bend

An everyday analogy helps: a strong stream of water from a hose remains straight on a calm day but bends if the wind blows hard enough. In Cygnus X‑1, the same principle applies on cosmic scales.

Using a technique called Very Long Baseline Interferometry (VLBI) (which combines radio telescopes across the Earth) astronomers obtained images sharp enough to detect tiny changes in the jet’s direction during the black hole’s orbit. The jet always bends away from the companion star, leaving no doubt that the stellar wind is responsible.

From this bending, the team measured a jet power of about 10³⁷ ergs per second.

This is an enormous amount of energy, comparable to the system’s total X‑ray output and, over the age of the system, similar to the energy released by a supernova explosion.

(An “erg” is a unit of energy used in astrophysics; 10³⁷ ergs per second is trillions of trillions of times more powerful than human technologies can produce.)

Although Cygnus X‑1 hosts a relatively small black hole (about 20 times the mass of the Sun), the same physics applies to supermassive black holes at the centres of galaxies. Their jets are thought to regulate how galaxies grow — a process known as black‑hole feedback.

“This measurement gives strong observational support to assumptions used in galaxy‑formation models,” says Bosch‑Ramon. “Understanding a nearby system like Cygnus X‑1 helps us better understand the role of black holes across the Universe.”

Beyond this specific system, the study introduces a new way to measure jet power directly, turning a complex interaction into a powerful scientific tool.

“What used to be considered a complication for modelling this system,” Bosch‑Ramon adds, “has become a unique opportunity to measure one of the most extreme phenomena in astrophysics.”

Reference
Prabu, S. et al. A jet bent by a stellar wind in the black hole X‑ray binary Cygnus X‑1. Nature Astronomy (2026).
https://doi.org/10.1038/s41550-026-02828-3

An international team led by researchers from the Institute of Cosmos Sciences of the University of Barcelona (ICCUB) has developed a new method that could significantly improve our understanding of the expansion of the Universe and the nature of dark energy. The work has been published today in Nature Astronomy.

The study presents a powerful framework called CIGaRS that allows scientists to extract much more information from exploding stars known as Type Ia supernovae, using mainly images rather than expensive spectroscopic observations. The results pave the way for making the most of the enormous amount of data expected from the next generation of astronomical surveys, especially the Vera C. Rubin Observatory.

Why supernovae matter for understanding the Universe

Type Ia supernovae are the explosive deaths of white dwarf stars. Because they tend to explode with almost the same intrinsic brightness, astronomers use them as “standard candles”: by comparing how bright they really are with how bright they look from Earth, scientists can measure cosmic distances.

This technique played a key role in the discovery that the expansion of the Universe is accelerating, a phenomenon attributed to dark energy, one of the biggest mysteries in modern physics.

However, there is a catch: not all Type Ia supernovae are exactly the same.

The problem: supernovae are affected by their environments

Over the last two decades, astronomers have found that the brightness of these supernovae depends slightly on the galaxies in which they explode. For example, supernovae in more massive or older galaxies tend to look a bit different from those in smaller or younger ones.

Until now, these effects have usually been corrected using simple, approximate adjustments. This can limit how precisely we can measure the distances to these supernovae.

A unified solution: modelling everything together

The new study tackles this problem head-on by modelling everything at once: the supernova explosions, the galaxies hosting them, dust that dims and reddens their light, how often supernovae occur over cosmic time and even the expansion of the Universe itself.

Instead of analysing each piece separately, the researchers built a single, self-consistent model that links all these elements physically and statistically.

“A powerful way of modeling the Universe is to simulate it ab initio in the computer using bayesian inference,” explains Raúl Jiménez (ICREA-ICCUB), co-author of the study. “This provides a way to vary all possible parameters at the same time to predict what Universe we live in. Furthermore, by having this capacity one can look into possible “unknown unknown” systematics to understand their effect. The impact of these systematics in our inference is arguably the most important missing ingredient in current approaches to model the Universe.”

Artificial intelligence meets cosmology

To make this ambitious approach computationally feasible, the team used a modern set of techniques known as simulation-based inference.

In simple terms, the method works like this:

1. Scientists simulate many possible universes using physical models.
2. A neural network (a type of artificial intelligence) learns how simulated data relate to the underlying physical parameters.
3. The trained system can then infer those parameters directly from real observations.

This allows the analysis of tens of thousands of supernovae at once, something that would be impossible with traditional methods.

A key result: precise distances without spectroscopy

One of the most important outcomes is that the method can estimate galaxy distances (redshifts) very accurately using only images (Redshift is a measure of how much the light from a galaxy is stretched as the Universe expands. It tells us how far away, and how long ago, we are seeing it).

The new approach achieves a precision comparable to spectroscopic measurements, but without needing spectra. This is crucial because future sky surveys will discover millions of supernova candidates, while only a small fraction can realistically be studied with spectroscopy.

Preparing for the Rubin Observatory era

The Vera C. Rubin Observatory, currently under construction in Chile, will soon begin a ten-year survey of the sky, detecting an unprecedented number of supernovae. Around 99% of them will be observed only photometrically, meaning through images in different colours.

The CIGaRS framework is designed precisely for this scenario.

“Unlike other frameworks, which require analytic simplifications, our no-compromise end-to-end simulation-based inference approach is uniquely capable of extracting the full cosmological and astrophysical information from the Rubin Observatory's hard-earned data, while avoiding the pitfalls of selection and modelling biases.” says Konstantin Karchev (ICCUB-SISSA Trieste), lead author of the study. 

Beyond cosmology: learning how stars explode

In addition to improving measurements of dark energy, the study also sheds light on how and when Type Ia supernovae form. By reconstructing how supernova rates depend on the ages of stars in galaxies, the model helps address long-standing questions about their progenitor systems.

The results show that combining physics-based modelling with artificial intelligence can overcome key limitations in current cosmological analyses. According to the authors, this approach could improve cosmological constraints by up to a factor of four compared to traditional methods that rely only on a small, spectroscopically observed subset of supernovae.

With the Rubin Observatory set to transform astronomy in the coming years, methods like CIGaRS ensure that we will be ready to fully understand the data and the Universe it reveals.

Reference:

Karchev, K., Trotta, R. & Jiménez, R. CIGaRS I: Combined simulation-based inference from Type Ia supernovae and host photometry. Nature Astronomy (2026). https://doi.org/10.1038/s41550-026-02842-5

A new study led by researchers at the Institute of Cosmos Sciences of the University of Barcelona (ICCUB) and the Institut d’Estudis Espacials de Catalunya (IEEC) reveals how the discs of galaxies like the Milky Way are impacted by ancient galactic collisions. 

Published in Monthly Notices of the Royal Astronomical Society, the research investigates how simulated galaxy collisions can fully or partially destroy stellar discs. Together with observational data of star clusters, the authors use this research to improve predictions for the time of the last significant galactic collision in our own Milky Way galaxy.
 

When did the Milky Way disc spin up?
 

The Milky Way disc is a vast, rotating system of stars shaped like a pancake, with spiral arms winding out from its centre. This disc contains most of the Galaxy’s stars, including the Sun, and rotates at a speed of over 220 kilometers per second.

Astronomers have long tried to determine when this rotating disc first formed. One key clue comes from the motions and ages of stars: at some point in the Galaxy’s early history, stars began to move in a coherent, rotating pattern, marking what scientists call the Galaxy’s “spin-up time.”

However, the Milky Way did not form in isolation. For decades, scientists suspected that a violent collision with a smaller galaxy played a major role in shaping the Milky Way we see today. This suspicion was confirmed in 2018, when data from the Gaia mission revealed a large population of stars whose unusual motions could only be explained by a massive merger around 10 billion years ago. This event is now known as the Gaia-Sausage-Enceladus (GSE) merger.

In this new study, simulations of Milky Way-like galaxies (the Auriga simulations) are used to investigate how rotating discs form under a variety of different scenarios. These show how galaxies like our Milky Way react to ancient collisions.
 

Key findings
 

The study shows that rotating stellar discs often form much earlier than previously assumed, but can be partially or completely destroyed by major galactic collisions. As a result, the moment when the Milky Way’s disc appears to “spin up” may not mark the first time a disc formed, but rather the time when the Galaxy recovered from a destructive merger.

Using insights from these simulations, the authors infer that the Gaia-Sausage-Enceladus merger likely occurred around 11 billion years ago, earlier than many previous estimates. Crucially, this timing coincides with a sharp increase in the birth of star clusters in the Milky Way. Such bursts of star formation are a natural consequence of galactic collisions, which compress gas and trigger intense star formation.

“Models of the Gaia-Sausage-Enceladus merger predict that a Galactic firework should have followed from the impact, raising star formation and fostering the formation of globular clusters. This is the first time this link has been made.” says collaborating author Chervin F. P. Laporte, researcher at CNRS.

“This research highlights the important relationship between galactic structure and ancient collisions, which must be understood in unison in order to understand the history of our Galaxy,” adds lead author Matthew D. A. Orkney, researcher at ICCUB and IEEC.

Whilst scientists can never travel back in time to observe the Milky Way in its youth, they can observe the formation of similar galaxies in the distant Universe with new data from the James Webb Space Telescope (JWST) and the Atacama Large Millimeter/submillimeter Array (ALMA), a powerful radio telescope.

Reference:

The full paper is available here, and the Auriga simulation data is publicly accessible for further research.

Orkney, Matthew; Laporte, Chervin. Build-up and survival of the disc: From numerical models of galaxy formation to the Milky Way. Monthly Notices of the Royal Astronomical Society. DOI: https://doi.org/10.1093/mnras/staf2154