The prime objective of the project is to uplift the existing Centre of Excellence AstroCeNT by transforming it into a fully independent, interdisciplinary, new legal entity: Astrocent Plus Particle Astrophysics Science and Technology Centre. Astrocent Plus will engage in cutting-edge research and development in astroparticle physics and in related aspects of innovative technology, addressing global challenges, such as healthcare, climate change and sustainable sources of energy. As a fully autonomous entity with a modern professional management and administrative structure, it will be the first scientific institution in astroparticle physics supported by Teaming for Excellence and the first one in the field in Poland. Acting in close cooperation with world-leading consortium partners, Astrocent Plus will be embedded in a network of international collaborations involved in frontier research, probing the invisible Universe through neutrino, cosmic-ray, gravitational-wave and dark matter detection. AstroCeNT and the field have a proven record of medical and commercial applications and after the uplift will bring further high-impact benefits to society and economy. The buildup of internationally-rooted research capacity, gained through strategic partnerships, will position the Centre to achieve a significant, measurable, improvement in research and innovation culture and long-term financial sustainability, in part through commercialisation. The Centre will improve mobility and gender balance, train new cadres of highly-qualified researchers in science and hi-tech industry, promote innovation and cooperation between scientists and industry and help Poland and the EU attain a competitive position in the global value chains. With modern management practices, Astrocent Plus will become the main hub for the rapidly-developing field of particle astrophysics and a role model for Poland and the region for excellence in basic sciences and fruitful cooperation with industry.

We propose a conceptual design study for a 12-metre wide-field spectroscopic survey telescope (WST) with simultaneous operation of a large field-of-view (3 sq. degree), high-multiplex (20,000) multi-object spectrograph (MOS) and a giant 3x3 arcmin integral field spectrograph (IFS). In scientific capability these specifications place WST far ahead of existing and planned facilities. In only 5 years of operation, the MOS would target 250 million galaxies and 25 million stars at low spectral resolution plus 2 million stars at high resolution. Without need for pre-imaged targets, the IFS would deliver 4 billion spectra offering many serendipitous discoveries. Given the current investment in deep imaging surveys and noting the diagnostic power of spectroscopy, WST will fill a crucial gap in astronomical capability and work in synergy with future ground and space-based facilities. We show how it can address outstanding scientific questions in the areas of cosmology; galaxy assembly, evolution, and enrichment, including our own Milky Way; the origin of stars and planets; and time domain and multi-messenger astrophysics. WST’s uniquely rich dataset may yield unforeseen discoveries in many of these areas. The study will deliver telescope and instrument designs, cost estimates, an updated science white paper and survey plan, concept studies for data management, and a facility operation concept. The telescope and instruments will be designed as an integrated system and will mostly use existing technology, with the aim to minimise the carbon footprint and environmental impact. We will propose WST as the next ESO project after completion of the 39-metre ELT. Our consortium includes institutes from Australia, which has a strategic partnership with ESO and aims to apply shortly for full membership. Together with ESO and institutes in 9 European countries, our team has the necessary technical and scientific expertise, and brings 70 years of in-kind effort to the proposed study.

Massive stars are the cornerstone of the dynamic and chemical evolution of the cosmos, enriching it as they evolve with chemically processed material that is blown away from their surface by energetic winds and eruption processes. Despite their importance, their evolution from cradle to death as spectacular supernova explosions still poses many mysteries due to crucial knowledge gaps in the physical processes taking place in their interior and atmosphere and the mutual influence by close-by siblings. Our ultimate goal is to elucidate the physical properties and evolution of massive stars impacted by companions, as well as their contribution to the generation of gravitational waves. For this, we wish to establish a multidisciplinary, international network of researchers from Europe and America with expertise in various disciplines, and with background in both theory and observations. We will exploit the avalanche of public data archives and develop machine learning algorithms to detect massive stars in binary and multiple systems, classify them, and create statistically meaningful samples for diverse evolutionary states. We will develop progressive methods of signal processing for the analysis of the stellar properties, and cutting-edge numerical codes to unveil the impact of stellar interaction and mass ejection on the evolution of the stars and stellar systems. The acquired results will significantly enhance our knowledge and lead to major advancements in all related fields. The bulk of exchanges will be undertaken by PhD students and Postdocs, whom we will educate and train in modern observing and data analysing techniques, machine learning algorithms, and in high-performance computing, equipping them with excellent skills for their future careers. We will organise schools, workshops and educational activities to share knowledge as well as disseminate our results, which will be major breakthroughs and will expand Europe's leading role in basic research.

We propose to carry out a project which will produce a decisive step towards improving the accuracy of the Hubble constant as determined from the Cepheid-SN Ia method to 1%, by using 28 extremely rare eclipsing binary systems in the LMC which offer the potential to determine their distances to 1%. To achieve this accuracy we will reduce the main error in the binary method by interferometric angular diameter measurements of a sample of red clump stars which resemble the stars in our binary systems. We will check on our calibration with similar binary systems close enough to determine their orbits from interferometry. We already showed the feasibility of our method which yielded the best-ever distance determination to the LMC of 2.2% from 8 such binary systems. With 28 systems and the improved angular diameter calibration we will push the LMC distance uncertainty down to 1% which will allow to set the zero point of the Cepheid PL relation with the same accuracy using the large available LMC Cepheid sample. We will determine the metallicity effect on Cepheid luminosities by a) determining a 2% distance to the more metal-poor SMC with our binary method, and by b) measuring the distances to LMC and SMC with an improved Baade-Wesselink (BW) method. We will achieve this improvement by analyzing 9 unique Cepheids in eclipsing binaries in the LMC our group has discovered which allow factor- of-ten improvements in the determination of all basic physical parameters of Cepheids. These studies will also increase our confidence in the Cepheid-based H0 determination. Our project bears strong synergy to the Gaia mission by providing the best checks on possible systematic uncertainties on Gaia parallaxes with 200 binary systems whose distances we will measure to 1-2%. We will provide two unique tools for 1-3 % distance determinations to individual objects in a volume of 1 Mpc, being competitive to Gaia already at a distance of 1 kpc from the Sun.