Search Publications
The nature of VX Sagitarii. Is it a TŻO, a RSG, or a high-mass AGB star?
Negueruela, I.; Tabernero, H. M.; Dorda, R. +1 more
Aims: We present a spectroscopic analysis of the extremely luminous red star VX Sgr based on high-resolution observations combined with AAVSO light curve data. Given the puzzling characteristics of VX Sgr, we explore three scenarios for its nature: a massive red supergiant (RSG) or red hypergiant (RHG), a Thorne Żytkow object, and an extreme …
Stellar clustering and orbital architecture of planetary systems
Adibekyan, V.; Sousa, S. G.; Barros, S. C. C. +9 more
Context. Revealing the mechanisms shaping the architecture of planetary systems is crucial for our understanding of their formation and evolution. In this context, it has been recently proposed that stellar clustering might be the key in shaping the orbital architecture of exoplanets.
Aims: The main goal of this work is to explore the factors…
Photometric selection and redshifts for quasars in the Kilo-Degree Survey Data Release 4
Heymans, C.; Hildebrandt, H.; Erben, T. +10 more
We present a catalog of quasars with their corresponding redshifts derived from the photometric Kilo-Degree Survey (KiDS) Data Release 4. We achieved it by training machine learning (ML) models, using optical ugri and near-infrared ZYJHKs bands, on objects known from Sloan Digital Sky Survey (SDSS) spectroscopy. We define inference subs…
MPS-ATLAS: A fast all-in-one code for synthesising stellar spectra
Solanki, S. K.; Shapiro, A. I.; Tagirov, R. V. +6 more
Context. Stellar spectral synthesis is essential for various applications, ranging from determining stellar parameters to comprehensive stellar variability calculations. New observational resources as well as advanced stellar atmosphere modelling, taking three dimensional effects from radiative magnetohydrodynamics calculations into account, requi…
Seasonal reappearance of HCl in the atmosphere of Mars during the Mars year 35 dusty season
Forget, F.; Montmessin, F.; Irwin, P. G. J. +15 more
Hydrogen chloride was discovered in the atmosphere of Mars for the first time during the global dust storm in Mars year (MY) 34 (July 2018) using the Atmospheric Chemistry Suite mid-infrared channel (ACS MIR) on the ExoMars Trace Gas Orbiter. The simultaneity of variations in dust and HCl, and a correlation between water vapour and HCl, led to the…
Molecular mapping of the PDS70 system. No molecular absorption signatures from the forming planet PDS70 b
Quanz, S. P.; Snellen, I. A. G.; Stolker, T. +7 more
Context. Determining the chemical properties of the atmosphere of young forming gas giants might shed light on the location their formation occurred and the mechanisms involved.
Aims: Our aim was to detect molecules in the atmosphere of the young forming companion PDS70 b by searching for atmospheric absorption features typical of substellar …
The star cluster age function in the Galactic disc with Gaia DR2. Fewer old clusters and a low cluster formation efficiency
Cantat-Gaudin, Tristan; Gieles, Mark; Anders, Friedrich +4 more
We perform a systematic reanalysis of the age distribution of Galactic open star clusters. Using a catalogue of homogeneously determined ages for 834 open clusters contained in a 2 kpc cylinder around the Sun and characterised with astrometric and photometric data from the Gaia satellite, we find that it is necessary to revise earlier works that r…
Spectroscopic study of CEMP-(s & r/s) stars. Revisiting classification criteria and formation scenarios, highlighting i-process nucleosynthesis
Goswami, Aruna; Goswami, Partha Pratim; Rathour, Rajeev Singh
Context. The origin of the enhanced abundances of both s- and r-process elements observed in a subclass of carbon-enhanced metal-poor (CEMP) stars, denoted CEMP-r/s stars, still remains poorly understood. The i-process nucleosynthesis has been suggested as one of the most promising mechanisms for the origin of these stars.
Aims: Our aim is to…
Day-night differences in Mars methane suggest nighttime containment at Gale crater
Atreya, Sushil K.; Vasavada, Ashwin R.; Moores, John E. +10 more
We report new measurements of atmospheric methane by the Curiosity rover's Tunable Laser Spectrometer that is part of the Sample Analysis at Mars suite (TLS-SAM), finding nondetections during two daytime measurements of average value 0.05 ± 0.22 ppbv (95% confidence interval CI). These are in marked contrast with nighttime background levels of 0.5…
Refined physical parameters for Chariklo's body and rings from stellar occultations observed between 2013 and 2020
Colas, F.; Bérard, D.; Snodgrass, C. +78 more
Context. The Centaur (10199) Chariklo has the first ring system discovered around a small object. It was first observed using stellar occultation in 2013. Stellar occultations allow sizes and shapes to be determined with kilometre accuracy, and provide the characteristics of the occulting object and its vicinity.
Aims: Using stellar occultati…