Search Publications
A new low-luminosity globular cluster discovered in the Milky Way with the VVVX survey
Minniti, D.; Fernández-Trincado, J. G.; Alonso-García, J. +4 more
Context. The VISTA Variables in the Via Láctea Extended Survey (VVVX) allows us to probe previously unexplored regions of the inner Milky Way (MW), especially those that are affected by stellar crowding and strong extinction.
Aims: Our long-term goal is to identify new star clusters and investigate them to reveal their true nature. In particu…
99 oscillating red-giant stars in binary systems with NASA TESS and NASA Kepler identified from the SB9-Catalogue
García, R. A.; Mathis, S.; Mathur, S. +6 more
Oscillating red-giant stars in binary systems are an ideal testbed for investigating the structure and evolution of stars in the advanced phases of evolution. With 83 known red giants in binary systems, of which only ∼40 have determined global seismic parameters and orbital parameters, the sample is small compared to the numerous known oscillating…
Gaia-predicted brown dwarf detection rates around FGK stars in astrometry, radial velocity, and photometric transits
Holl, B.; Lindegren, L.; Perryman, M. +2 more
Context. After more than two decades of relevant radial velocity surveys, the current sample of known brown dwarfs (BDs) around FGK stars is only of the order of 100, limiting our understanding of their occurrence rate, properties, and formation. The ongoing ESA mission Gaia has already collected more than its nominal 5 years of mission data, and …
Impact of the image alignment over frequency for the VLBI Global Observing System
Xu, Ming H.; Savolainen, Tuomas; Anderson, James M. +4 more
Aims: The VLBI Global Observing System (VGOS), which is the next generation of geodetic very long baseline interferometry (VLBI), observes simultaneously in four frequency bands in the range 3.0-10.7 GHz (expected to be extended to 14 GHz). Because source structure changes with frequency, we aim to study the source position estimates from the…
Theoretical analysis of surface brightness-colour relations for late-type stars using MARCS model atmospheres
Plez, B.; Nardetto, N.; Mourard, D. +1 more
Context. Surface brightness-colour relations (SBCRs) are largely used for general studies in stellar astrophysics and for determining extragalactic distances. Based on a careful selection of stars and a homogeneous methodology, it has been recently shown that the SBCR for late-type stars depends on the spectral type and luminosity class.
Aims…
Fundamental stellar parameters of benchmark stars from CHARA interferometry. II. Dwarf stars
White, T. R.; Casagrande, L.; Nordlander, T. +3 more
Context. Stellar models applied to large stellar surveys of the Milky Way need to be properly tested against a sample of stars with highly reliable fundamental stellar parameters. We have established a programme aiming to deliver such a sample of stars.
Aims: Here we present new fundamental stellar parameters of nine dwarf stars that will be …
Dynamical parallax, physical parameters, and evolutionary status of the components of the bright eclipsing binary α Draconis
Bodensteiner, J.; Bowman, D. M.; Tkachenko, A. +13 more
Aims: Both components of the bright eclipsing binary α Dra have been resolved using long baseline interferometry and the secondary component has been shown to contribute approximately 15% of the total flux; however, a spectroscopic detection of the companion star has so far been unsuccessful. We aim for a firm spectroscopic detection of the s…
Lithium on the lower red giant branch of five Galactic globular clusters
Salaris, M.; Pancino, E.; Monaco, L. +3 more
Context. Lithium is one of the few elements produced during Big Bang nucleosynthesis in the early universe. Moreover, its fragility makes it useful as a proxy for stellar environmental conditions. As such, the lithium abundance in old systems is at the core of various astrophysical investigations.
Aims: Stars on the lower red giant branch are…
Asteroid astrometry by stellar occultations: Accuracy of the existing sample from orbital fitting
Tanga, P.; Spoto, F.; Herald, D. +2 more
Context. The technique of stellar occultations, greatly enhanced by the publication of the Gaia data releases, permits not only the determination of asteroid size and shape, but also the retrieval of additional, very accurate astrometry, with a possible relevant impact on the study of dynamical properties. The use of Gaia as reference catalogue an…
Photometric properties of nuclear star clusters and their host galaxies in the Fornax cluster
Janz, Joachim; Peletier, Reynier F.; Salo, Heikki +2 more
Aims: We aim to investigate the relations between nuclear star clusters (NSCs) and their host galaxies and to offer a comparison between the structural properties of nucleated and non-nucleated galaxies. We also address the environmental influences on the nucleation of galaxies in the Fornax main cluster and the Fornax A group.
Methods: …