Search Publications
The longevity of the oldest open clusters. Structural parameters of NGC 188, NGC 2420, NGC 2425, NGC 2682, NGC 6791, and NGC 6819
Jordi, C.; Silva-Villa, E.; Vallenari, A. +5 more
Context. The dynamical evolution of open clusters is driven by stellar evolution, internal dynamics, and external forces, which according to dynamical simulations will lead to their evaporation over a timescale of about 1 Ga. However, about 10% of the known open clusters are older. These latter are special systems whose detailed properties are rel…
Comparing bulge RR Lyrae stars with bulge giants: Insight from 3D kinematics
Zoccali, M.; Valenti, E.; Contreras Ramos, R. +6 more
Context. The structure and kinematics of the old component of the Galactic bulge are still a matter of debate. It is clear that the bulk of the bulge as traced by red clump stars includes two main components, which are usually identified as the metal-rich and metal-poor components. They have different shapes, kinematics, mean metallicities, and al…
Stellar companions and Jupiter-like planets in young associations
Barbato, D.; D'Orazi, V.; Nascimbeni, V. +9 more
Context. The formation mechanisms of stellar, brown dwarf, and planetary companions, their dependencies on the environment and their interactions with each other are still not well established. Recently, combining high-contrast imaging and space astrometry we found that Jupiter-like (JL) planets are frequent in the β Pic moving group (BPMG) around…
Emergence hour-by-hour of r-process features in the kilonova AT2017gfo
Heintz, Kasper E.; Watson, Darach; Väisänen, Petri +4 more
The spectral features in the optical/near-infrared counterparts of neutron star mergers (kilonovae, KNe) evolve dramatically on hourly timescales. To examine the spectral evolution, we compiled a temporal series that was complete at all observed epochs from 0.5 to 9.4 days of the best optical/near-infrared (NIR) spectra of the gravitational-wave d…
Extended high-ionization [Mg IV] emission tracing widespread shocks in starbursts seen by JWST/NIRSpec
Arribas, Santiago; Perna, Michele; Colina, Luis +6 more
We report the detection of extended (> 0.5-1 kpc) high-ionization [Mg IV] 4.487 µm (80 eV) emission in four local luminous infrared galaxies observed with JWST/NIRSpec. Excluding the nucleus and outflow of the Type 1 active galactic nucleus (AGN) in the sample, we find that the [Mg IV] luminosity is well correlated with that of H recombin…
Gaia-Sausage-Enceladus star formation history as revealed by detailed elemental abundances: An archival study using SAGA data
Skúladóttir, Á.; Feltzing, S.; Ernandes, H. +1 more
Context. The Gaia-Sausage-Enceladus merger was a major event in the history of the Milky Way. Debris from this merger has been extensively studied with full kinematic data from the Gaia mission. Understanding the star formation history of the progenitor galaxy aids in our understanding of the evolution of the Milky Way and galaxy formation in gene…
Seven new triply eclipsing triple star systems
Mitnyan, T.; Pál, A.; Vanderburg, A. +19 more
Aims: We have identified nearly a hundred close triply eclipsing hierarchical triple star systems from data taken with the space telescope TESS. These systems are noteworthy in that we can potentially determine their dynamical and astrophysical parameters with a high precision. In the present paper, we report the comprehensive study of seven …
X-Shooting ULLYSES: Massive stars at low metallicity: VI. Atmosphere and mass-loss properties of O-type giants in the Small Magellanic Cloud
van Loon, J. Th.; Kaper, L.; Crowther, P. A. +21 more
Context. Mass loss through a stellar wind is an important physical process that steers the evolution of massive stars and controls the properties of their end-of-life products, such as the supernova type and the mass of compact remnants. To probe its role in stellar evolution over cosmic time, mass loss needs to be studied as function of metallici…
Disk Evolution Study Through Imaging of Nearby Young Stars (DESTINYS): The SPHERE view of the Orion star-forming region
Ginski, C.; Garufi, A.; Dominik, C. +17 more
Context. Resolved observations at near-infrared (near-IR) and millimeter wavelengths have revealed a diverse population of planet-forming disks. In particular, near-IR scattered light observations usually target close-by, low-mass star-forming regions. However, disk evolution in high-mass star-forming regions is likely affected by the different en…
Empirical mass-loss rates and clumping properties of O-type stars in the Large Magellanic Cloud
Puls, J.; de Koter, A.; Decin, L. +6 more
Context. The nature of mass-loss in massive stars is one of the most important and difficult to constrain processes in the evolution of massive stars. The largest observational uncertainties are related to the influence of metallicity and wind structure with optically thick clumps. Aims. We aim to constrain the wind parameters of sample of 18 O-ty…