A5058172419- Stellar, planetary, and galactic studies
- Astro and Planetary Science
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Adaptive optics and wavefront sensing
- Solar and Space Plasma Dynamics
- Calibration and Measurement Techniques
- Geophysics and Gravity Measurements
- Ionosphere and magnetosphere dynamics
- Photocathodes and Microchannel Plates
- Particle Accelerators and Free-Electron Lasers
- Geomagnetism and Paleomagnetism Studies
- Astronomical Observations and Instrumentation
- Particle accelerators and beam dynamics
- Gamma-ray bursts and supernovae
- Atmospheric Ozone and Climate
- Atomic and Subatomic Physics Research
- Pulsars and Gravitational Waves Research
- CCD and CMOS Imaging Sensors
- Spectroscopy and Laser Applications
- Atmospheric and Environmental Gas Dynamics
- Atomic and Molecular Physics
- Superconducting and THz Device Technology
- Spectroscopy Techniques in Biomedical and Chemical Research
- Spacecraft and Cryogenic Technologies
Institut de Recherche en Astrophysique et Planétologie
2023-2024
Université de Toulouse
2023-2024
Centre National de la Recherche Scientifique
2023-2024
Uppsala University
2016-2023
Institute of Astrophysics and Space Sciences
2022
University of Lisbon
2022
Aarhus University
2022
European Southern Observatory
2016-2019
Context . General circulation models of gas giant exoplanets predict equatorial jets that drive inhomogeneities in the atmospheric physical parameters across planetary surface. Aims We studied transmission spectrum hot Jupiter WASP-127 b during one transit K band with CRIRES + Methods Telluric and stellar signals were removed from data using SYSREM signal was investigated cross-correlation technique. After detecting a spectral indicative inhomogeneities, we employed Bayesian retrieval...
The CRyogenic InfraRed Echelle Spectrograph (CRIRES) Upgrade project CRIRES$^{+}$ extended the capabilities of CRIRES. It transformed this VLT instrument into a cross-dispersed spectrograph to increase wavelength range that is covered simultaneously by up factor ten. In addition, new detector focal plane array three Hawaii 2RG detectors with 5.3 $\mu$m cutoff replaced existing detectors. Amongst many other improvements, spectropolarimetric unit was added and calibration system has been...
The dayside atmospheres of ultra-hot Jupiters (UHJs) are predicted to possess temperature inversion layers with extremely high temperatures at altitudes. We observed the thermal emission spectra WASP-18b and WASP-76b new CRIRES+ high-resolution spectrograph near-infrared wavelengths. Using cross-correlation technique, we detected strong CO lines in both planets, which confirms existence inversions on their hemispheres. two planets first UHJs orbiting F-type stars detected; previous...
Abstract The nearby M dwarf binary GJ65 AB, also known as BL Cet and UV Cet, is a unique benchmark for investigation of dynamo-driven activity low-mass stars. Magnetic was repeatedly assessed by indirect means, such studies flares, photometric variability, X-ray, radio emission. Here, we present direct analysis large-scale local surface magnetic fields in both components. Interpreting high-resolution circular polarization spectra (sensitive to field geometry) uncovered remarkable difference...
Context. One clear manifestation of dynamo action on the Sun is 22-yr magnetic cycle, exhibiting a polarity reversal and periodic conversion between poloidal toroidal fields. For M dwarfs, several authors claim evidence activity cycles from photometry analyses spectroscopic indices, but no has been identified spectropolarimetric observations. These stars are excellent laboratories to investigate dynamo-powered fields under different stellar interior conditions, that partly or fully...
Accurately estimating the C/O ratio of hot Jupiter atmospheres is a promising pathway towards understanding planet formation and migration, as well clouds overall atmospheric composition. The atmosphere WASP-43b has been extensively analysed using low-resolution observations with HST Spitzer, but these previous did not cover K band, which hosts prominent spectral features major carbon-bearing species such CO CH 4 . As result, ability to establish precise constraints on was limited. Moreover,...
Despite recent progress in the spectroscopic characterization of individual exoplanets, atmospheres key ultra-hot Jupiters (UHJs) still lack comprehensive investigations. These include WASP-178b, one most irradiated UHJs known to date. We observed dayside emission signal this planet with CRIRES + spectral K band. By applying cross-correlation technique and a Bayesian retrieval framework high-resolution spectra, we identified signature 12 CO ( S/N = 8.9) H 2 O 4.9), strong atmospheric thermal...
Abstract One of the outstanding goals planetary science community is to measure present-day atmospheric composition planets and link this back formation. As giant are formed by accreting gas, ices, rocks, constraining relative amounts these components critical understand their formation evolution. For most known planets, including solar system giants, difficult as they reside in a temperature regime where only volatile elements (e.g., C, O) can be measured, while refractories Fe, Ni)...
Aims. In this paper, we aim to measure the strength of surface magnetic fields for a sample five intermediate mass T Tauri stars and one low star from late-F mid-K spectral types. While at range have been extensively characterized, our work complements previous studies towards range; complementary study is key evaluate how evolve during transition convective radiative core.
We aim to characterise the small-scale magnetic fields for a sample of 16 Sun-like stars and investigate capabilities newly upgraded near-infrared (NIR) instrument CRIRES$^+$ at VLT in context field studies. Our targets also had their studied optical, which allows us compare properties different spatial scales on stellar surface contrast measurements wavelengths. analyse Zeeman broadening signature six magnetically sensitive insensitive \ion{Fe}{I} lines H-band measure surface. use polarised...
Magnetic field investigations of Sun-like stars, using Zeeman splitting non-polarised spectra, in the optical and H-band have found significantly different magnetic strengths for same cause which is currently unknown. We aim to further investigate this issue by systematically analysing ξ Boo A, a magnetically active G7 dwarf, spectral lines at wavelengths. used polarised radiative transfer accounting departures from local thermodynamic equilibrium generate synthetic spectra. To find optical,...
Since the recent discovery of directly imaged super-Jovian planet AF,Lep,b, several studies have been conducted to characterize its atmosphere and constrain orbital parameters. AF,Lep,b has a measured dynamical mass $3.68 ± 0.48$ radius $1.3 0.15$ nearly circular orbit in spin-orbit alignment with host star, relatively high metallicity, near-solar super-solar ratio. However, key parameters such as rotational velocity radial not estimated thus far, they require high-resolution spectroscopic...
The ultra-hot Jupiter (UHJ) TOI-2109b marks the lower edge of equilibrium temperature gap between 3500,K and 4500,K, an unexplored thermal regime that separates KELT-9b, hottest planet yet discovered, from all other currently known gas giants. To study thermochemical structure TOI-2109b's atmosphere, we obtained high-resolution emission spectra both planetary day- nightsides with CAHA/CARMENES VLT/CRIRES^+. By applying cross-correlation technique to spectra, identified signatures Fe i...
Spectropolarimetry of atomic lines in the spectra Betelgeuse and other red supergiants (RSG) typically presents broad line profiles linear polarization, but narrow intensity. By contrast, recent observations RSG RW Cep show intensity profiles, comparable to those polarization. This observation suggests that difference Stokes Q/U I profile widths noted many RSGs arises from temporary atmospheric conditions a given star. We propose an explanation for both cases based on presence strong...
In this paper we present an analysis of the first high-resolution full Stokes vector spectropolarimetric observations active M dwarf AD Leo. Based on collected in 2016 with ESPaDOnS instrument at CFHT, derived least-squares deconvolved profiles and detected linear polarization signatures spectral lines. At same time, discovered that circular polarisation corresponding to our data set are significantly weaker compared all archival spectra Leo, which exhibited approximately constant over...
The adaptive optics (AO) assisted CRIRES instrument is an IR (0.92 - 5.2 μm) high-resolution spectrograph was in operation from 2006 to 2014 at the Very Large Telescope (VLT) observatory. a unique instrument, accessing parameter space (wavelength range and spectral resolution) up now largely uncharted. It consisted of single-order providing long-slit (40 arcsecond) spectroscopy with resolving power R=100 000. However setup limited narrow, single-shot, about 1/70 central wavelength,...
General circulation models of gas giant exoplanets predict equatorial jets that drive inhomogeneities across the planetary atmosphere. We studied transmission spectrum hot Jupiter WASP-127b during one transit in K band with CRIRES+. Telluric and stellar signals were removed from data using SYSREM signal was investigated cross-correlation (CCF) technique. After detecting a spectral indicative atmospheric inhomogeneities, we employed Bayesian retrieval framework 2D modelling approach tailored...
Context. The accurate characterisation of the stellar magnetism planetary host stars has been gaining momentum, especially in context transmission spectroscopy investigations exoplanets. Indeed, magnetic field regulates amount energetic radiation and wind impinging on planets, as well presence inhomogeneities surface that hinder precise extraction atmospheric absorption signal. Aims. We initiated a spectropolarimetric campaign to unveil properties known exoplanet hosting included current...
The extreme temperature gradients from day- to nightside in the atmospheres of hot Jupiters generate fast winds form equatorial jets or day-to-night flows. Observations blue-shifted and red-shifted signals transmission dayside spectra WASP-189\,b have sparked discussions about nature on this planet. To investigate structure atmosphere ultra-hot Jupiter WASP-189\,b, we studied its emission spectrum with CRIRES$^+$ spectral K band. After removing stellar telluric lines, used cross-correlation...
We report time-resolved, high-resolution optical spectropolarimetric observations of the young double-lined spectroscopic binary V1878 Ori. Our were collected with ESPaDOnS spectropolarimeter at Canada-France-Hawaii Telescope through BinaMIcS large programme. Ori A and B are partially convective intermediate mass weak-line T Tauri stars on an eccentric asynchronous orbit. also acquired X-ray periastron outside periastron. Using least-squares deconvolution technique (LSD) to combine...
EX Lupi is the prototype of Lup-type stars, which are classical T Tauri stars (cTTSs) with luminosity bursts and outbursts 1 to 5 magnitudes that last for a few months years. These events ascribed an episodic accretion can occur repeatedly, but whose physical mechanism still debated. We aim investigate magnetically driven Lup in quiescence. include first time study small- large-scale magnetic field. This allows us characterise magnetospheric process system completely. used...
Context. Betelgeuse is a red supergiant (RSG) that known to vary semi-regularly on both short and long timescales. The origin of the period has often been associated with radial pulsations, but could also be due convection motions present at surface RSGs. Aims. We investigate link between activity variability star. Methods. Linear polarization in proxy unrelated pulsations. Using ten years spectropolarimetric data Betelgeuse, we looked for periodicities least-squares deconvolution profiles...
One of the outstanding goals planetary science community is to measure present-day atmospheric composition planets and link this back formation. As giant are formed by accreting gas, ices, rocks, constraining relative amounts these components critical understand their formation evolution. For most known planets, including Solar System giants, difficult as they reside in a temperature regime where only volatile elements (e.g., C, O) can be measured, while refractories Fe, Ni) condensed deep...
We aim to characterise the surface magnetic fields of a sample 8 T Tauri stars from high-resolution near-IR spectroscopy. Some in our are known be previous spectroscopic or spectropolarimetric studies. Our goals 1) apply Zeeman broadening modelling with data, 2) expand measured field strengths, 3) investigate possible rotational long-term variability by comparing spectral time series given targets, and 4) compare modulus <B> tracing small-scale those large-scale derived Stokes V Doppler...
One manifestation of dynamo action on the Sun is 22-yr magnetic cycle, exhibiting a polarity reversal and periodic conversion between poloidal toroidal fields. For M dwarfs, several authors claim evidence activity cycles from photometry analyses spectroscopic indices, but no clear has been identified spectropolarimetric observations. Our aim to monitor evolution large-scale field AD Leo, which shown hints secular past dedicated campaigns. We analysed near-infrared observations active dwarf...