Search Publications
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…
Turbulence and wave transmission at an ICME-driven shock observed by the Solar Orbiter and Wind
Kilpua, E. K. J.; Horbury, T. S.; O'Brien, H. +10 more
Aims: An interplanetary coronal mass ejection (ICME) event was observed by the Solar Orbiter at 0.8 AU on 2020 April 19 and by Wind at 1 AU on 2020 April 20. Futhermore, an interplanetary shock wave was driven in front of the ICME. Here, we focus on the transmission of the magnetic fluctuations across the shock and we analyze the characterist…
Indications for very high metallicity and absence of methane in the eccentric exo-Saturn WASP-117b
Henning, Thomas; Jordán, Andrés; Apai, Dániel +12 more
Aims: We investigate the atmospheric composition of the long-period (Porb = 10 days) eccentric exo-Saturn WASP-117b. WASP-117b could be similar in atmospheric temperature and chemistry to WASP-107b. In mass and radius, WASP-117b is similar to WASP-39b, which allows a comparative study of these planets.
Methods: We analyzed a n…
Optimising and comparing source-extraction tools using objective segmentation quality criteria
Venhola, Aku; Peletier, Reynier; Chamba, Nushkia +4 more
Context. With the growth of the scale, depth, and resolution of astronomical imaging surveys, there is increased need for highly accurate automated detection and extraction of astronomical sources from images. This also means there is a need for objective quality criteria, and automated methods to optimise parameter settings for these software too…
A bright inner disk and structures in the transition disk around the very low-mass star CIDA 1
Testi, L.; Tazzari, M.; Natta, A. +7 more
The frequency of Earth-sized planets in habitable zones appears to be higher around M-dwarfs, making these systems exciting laboratories to investigate planet formation. Observations of protoplanetary disks around very low-mass stars and brown dwarfs remain challenging and little is known about their properties. The disk around CIDA 1 (~0.1-0.2 M<…
TOI-269 b: an eccentric sub-Neptune transiting a M2 dwarf revisited with ExTrA
Bouchy, F.; de Medeiros, J. R.; Helled, R. +59 more
We present the confirmation of a new sub-Neptune close to the transition between super-Earths and sub-Neptunes transiting the M2 dwarf TOI-269 (TIC 220 479 565, V = 14.4 mag, J = 10.9 mag, R⋆ = 0.40 R⊙, M⋆ = 0.39 M⊙, d = 57 pc). The exoplanet candidate has been identified in multiple TESS sectors, and va…