Search Publications
Detection of faint secondary companions in spectroscopic binaries
González, J. F.; Martínez, C. I.; Alejo, A.
Context. Most known spectroscopic binaries are detected through the variation in the radial velocity of the primary star, while the spectral features of the secondary companion remain hidden in the noise. Aims. We present a novel technique for the spectroscopic detection of low-luminosity secondary companions of binary stars. The main goal is to e…
Unequivocal detection of the tidal deformation of a red giant in a binary system via interferometry
Boffin, Henri M. J.; Merc, Jaroslav
While mass transfer in binary systems is a crucial aspect of binary evolution models, it remains far from understood. HD 352 is a spectroscopic binary exhibiting ellipsoidal variability, likely due to a tidally deformed giant donor filling its Roche lobe and transferring matter to a faint companion. Here, we analyze VLTI/PIONIER interferometric ob…
Discovery of three magnetic helium-rich hot subdwarfs with SALT
Dorsch, M.; Jeffery, C. S.; Woolf, V. M. +6 more
Magnetic fields with strengths ranging from 300 to 500 kG have recently been discovered in a group of four extremely similar helium-rich hot subdwarf (He-sdO) stars. In addition to their strong magnetic fields, these He-sdO stars are characterised by common atmospheric parameters, clustering around Teff = 46 500 K, a log ɡ/cm s‑1
Linear polarization study of open clusters in the anticenter direction: Signature of the spiral arms
Ganesh, Shashikiran; Joshi, Santosh; Uppal, Namita +2 more
Aims. Our objective is to investigate the distribution of dust and associated large-scale structures of the Galaxy using optical linear polarization measurements of various open clusters located at different distances in the Galactic anticenter direction. Methods. We present R-band linear polarization observations of stars toward five open cluster…
Ups and downs in the X-ray emission of the colliding wind binaries HD 168112 and HD 167971
Blomme, R.; Nazé, Y.; Rauw, G. +2 more
Context. The long-period O-star binary system HD 168112 and the triple O-star system HD 167971 are well-known sources of non-thermal radio emission that arises from a colliding wind interaction. The wind-wind collisions in these systems should result in phase-dependent X-ray emissions. The presence of a population of relativistic electrons in the …
The ESO-VLT MIKiS survey reloaded: The internal kinematics of the core of M75
Vesperini, Enrico; Cadelano, Mario; Pallanca, Cristina +7 more
We present the results of a study aimed at characterizing the kinematics of the inner regions of the halo globular cluster M75 (NGC 6864) based on data acquired as part of the ESO-VLT Multi-Instrument Kinematic Survey (MIKiS) of Galactic globular clusters. Our analysis includes the first determination of the line-of-sight velocity dispersion profi…
The outskirts of M33: Tidally induced distortions versus signatures of gas accretion
Burkert, Andreas; Corbelli, Edvige
Aims: We investigate a possible close encounter between M33 and M31 in the past to understand the role of galaxy-galaxy interactions in shaping the matter distribution in galaxy outskirts.
Methods: By examining a variety of initial conditions, we recovered possible orbital trajectories of M33, M31, and the Milky Way in the past, which ar…
Detection of the [C I] λ8727 emission line. Low-ionization structures in NGC 7009
Boumis, P.; Walsh, J. R.; Akras, S. +5 more
We report the first spatially resolved detection of the near-infrared [C I] λ8727 emission from the outer pair of low-ionization structures in the planetary nebula NGC 7009 from data obtained by the Multi Unit Spectroscopic Explorer integral field unit. This atomic carbon emission marks the transition zone between ionized and neutral gas and for t…
Gaia21blx: Complete resolution of a binary microlensing event in the Galactic disk
Rybicki, K. A.; Wyrzykowski, Ł.; Snodgrass, C. +24 more
Context. Gravitational microlensing is a method that is used to discover planet-hosting systems at distances of several kiloparsec in the Galactic disk and bulge. We present the analysis of a microlensing event reported by the Gaia photometric alert team that might have a bright lens.
Aims: In order to infer the mass and distance to the lensi…
High-resolution transmission spectroscopy of the hot-Saturn HD 149026b
Haardt, Francesco; Rainer, Monica; Borsa, Francesco +1 more
Advances in modern technology have enabled the characterization of exoplanetary atmospheres, which can be achieved by exploitation of the transmission spectroscopy technique. We performed visible (VIS) and near-infrared (NIR) high-resolution spectroscopic observations of one transit of HD 149026b, a close-in orbit sub-Saturn exoplanet by using the…