Context. We analyse multi-colour photometric and spectroscopic observations of the young stellar object (YSO) Gaia20bdk. Aims. We aim to investigate the exact nature of the eruptive phenomenon that the star has been undergoing since 2018. Methods. We used public-domain archival photometry to characterise the quiescent phase and to establish the

Context. The new census of massive stars in the Carina Nebula reveals the presence of 54 apparently single O-type stars in the Car OB1 association, an extremely active star-forming region that hosts some of the most luminous stars of the Milky Way. A detailed spectroscopic analysis of the current most complete sample of O-type stars in the

We report follow-up observations of three poorly studied AM CVn-type binaries: CRTS CSS150211 J091017-200813, NSV 1440, and SDSS J183131.63+420220.2. Analysing time-series photometry obtained with a range of ground-based facilities as well as with the Transiting Exoplanet Survey Satellite (TESS), we determine the superhump period of CRTS J0910-2008

Context. The large-scale linear halo bias encodes the relation between the clustering of dark-matter (DM) halos and that of the underlying matter density field. Although the primary dependence of bias on halo mass is well understood in the context of structure formation, the physical origins of the multiple additional relations at fixed halo mass

To constrain cosmological models beyond ACDM, the development of the Euclid analysis pipeline requires simulations that capture the non-linear phenomenology of such models. We present an overview of numerical methods and N-body simulation codes developed to study the non-linear regime of structure formation in alternative dark energy and modified

The Cosmic Dawn Survey (DAWN survey) provides multiwavelength (UV/optical to mid-IR) data across the combined 59 deg 2 of the Euclid Deep and Auxiliary fields (EDFs and EAFs). In this work, the first public data release from the DAWN survey is presented. The catalogues made available herein consist of a subset of the full DAWN survey that includes