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We derive stellar ages, from evolutionary tracks, and metallicities,from Strömgren photometry, for a sample of 5828 dwarf and sub-dwarfstars from the Hipparcos Catalogue. This stellar disk sample is used toinvestigate the age-metallicity diagram in the solar neighbourhood. Suchdiagrams are often used to derive a so called age-metallicity relation.Because of the size of our sample, we are able to q

The dense environment of globular clusters (GCs) can facilitate the formation of binary black holes (BBHs), some of which can merge with gravitational waves within the age of the Universe. We have performed a survey of Monte Carlo simulations following the dynamical evolution of GCs with different masses, sizes, and binary fractions and explored the impact of the host GC properties on the formatio

Icy pebbles may play an important role in planet foation close to the water ice line of protoplanetary discs. There, dust coagulation is more efficient and recondensation of vapour on pebbles may enhance their growth outside the ice line. Previous theoretical studies showed that disruption of icy pebbles due to sublimation increases the growth rate of pebbles inside and outside the ice line, by fr

We present 63 new multi-site radial velocity (RV) measurements of the K1III giant HD 76920, which was recently reported to host the most eccentric planet known to orbit an evolved star. We focused our observational efforts on the time around the predicted periastron passage and achieved near-continuous phase coverage of the corresponding RV peak. By combining our RV measurements from four differen

Context. The Gaia Early Data Release 3 (Gaia EDR3) contains results derived from 78 billion individual field-of-view transits of 2.5 billion sources collected by the European Space Agency's Gaia mission during its first 34 months of continuous scanning of the sky. Aims. We describe the input data, which have the form of onboard detections, and the modeling and processing that is involved in cross-

The metal-poor stars in the bulge are important relics of the Milky Way's formation history, as simulations predict that they are some of the oldest stars in the Galaxy. In order to determine if they are truly ancient stars, we must understand their origins. Currently, it is unclear if the metal-poor stars in the bulge ([Fe/H] < -1 dex) are merely halo interlopers, a unique accreted population, pa

Estimating age distributions, or star formation histories, of stellar populations in the Milky Way is important in order to study the evolution of trends in elemental abundances and kinematics. We build on previous work to develop an algorithm for estimating the age-metallicity distribution which uses the full age-metallicity probability density functions (PDFs) of individual stars. No assumptions

Gas-giant planets, like Jupiter and Saturn, acquire massive gaseous envelopes during the approximately 3 Myr-long lifetimes of protoplanetary discs. In the core accretion scenario, the formation of a solid core of around ten Earth masses triggers a phase of rapid gas accretion. Previous 3D grid-based hydrodynamical simulations found that runaway gas accretion rates correspond to approximately 10 t

We have identified a first group of 33 new candidates for symbiotic stars (SySt) of the accreting-only variety among the 600 255 stars so far observed by the GALactic Archaeology with HERMES (GALAH) high-resolution spectroscopic survey of the Southern hemisphere, more than doubling the number of those previously known. GALAH aims to high latitudes and this offers the possibility to sound the Galax

We present a neural network autoencoder structure that is able to extract essential latent spectral features from observed spectra and then reconstruct a spectrum from those features. Because of the training with a set of unpeculiar spectra, the network is able to reproduce a spectrum of high signal-to-noise ratio that does not show any spectral peculiarities, even if they are present in an observ

We employed the VISTA near-infrared YJKssurvey of the Magellanic System (VMC) to analyse the Y, J, and Ks light curves of δCepheid stars (DCEPs) in the Large Magellanic Cloud (LMC). Our sample consists of 4408 objects accounting for 97 per cent of the combined list of OGLE IV and Gaia DR2 DCEPs. We determined a variety of period-luminosity (PL) and period-Wesenheit PW relationships for Fundamental

We explore the multiphase structure of the circumgalactic medium (CGM) probed by synthetic spectra through a cosmological zoom-in galaxy formation simulation. We employ a Bayesian method for modelling a combination of absorption lines to derive physical properties of absorbers with a formal treatment of detections, including saturated systems, and non-detections in a uniform manner. We find that i

While the number of stars in the Galactic bulge with detailed chemical abundance measurements is increasing rapidly, the inner Galactic bulge (|b| < 2°) remains poorly studied, due to heavy interstellar absorption and photometric crowding. We have carried out a high-resolution IR spectroscopic study of 72 M giants in the inner bulge using the CRIRES (ESO/VLT) facility. Our spectra cover the wavele

This article is an update of the review of the FORS system published in Immunohematology in 2017 (Hult AK, Olsson ML. The FORS awakens: review of a blood group system reborn. Immunohematology 2017;33:64-72). This update incorporates the most recently presented knowledge on this still enigmatic system and its genetic, enzymatic, and immunological aspects. Further insight into the genetic variation

Mergers of neutron stars (NS) and white dwarfs (WD) may give rise to observable explosive transientevents. We use 3D hydrodynamical (SPH) simulations, as well as 2D hydrodynamical-thermonuclearsimulations (using the FLASH AMR code) to model the disruption of CO-WDs by NSs, whichproduce faint transient events. We post-process the simulations using a large nuclear network andmake use of the SuperNu

The dynamical formation of black hole binaries in globular clusters that merge due to gravitational waves occurs more frequently in higher stellar density. Meanwhile, the probability to form intermediate mass black holes (IMBHs) also increases with the density. To explore the impact of the formation and growth of IMBHs on the population of stellar mass black hole binaries from globular clusters, w

The velocity distribution of stars in the Galactic disc is complex and consists of a vast number of kinematic structures, that is, stars that share similar velocity components. The reasons why some stars move together may be different and are related to dynamical processes connected to the Galaxy, both internal as well as external ones, such as resonances with the Galactic bar or the Galactic spir

Studies of the kinematics and chemical compositions of Galactic globular clusters (GCs) enable the reconstruction of the history of star formation, chemical evolution, and mass assembly of the Galaxy. Using the latest data release (DR16) of the SDSS/APOGEE survey, we identify 3090 stars associated with 46 GCs. Using a previously defined kinematic association, we break the sample down into eight se