C. Paladini
A5013657336- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Astronomical Observations and Instrumentation
- Adaptive optics and wavefront sensing
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Atmospheric Ozone and Climate
- Advanced Measurement and Metrology Techniques
- Calibration and Measurement Techniques
- Molecular Spectroscopy and Structure
- Pulsars and Gravitational Waves Research
- Solar and Space Plasma Dynamics
- Optical measurement and interference techniques
- Spectroscopy and Laser Applications
- History and Developments in Astronomy
- Galaxies: Formation, Evolution, Phenomena
- Structural Health Monitoring Techniques
- Chemical Thermodynamics and Molecular Structure
- Astronomical and nuclear sciences
- Heat Transfer Mechanisms
- Bee Products Chemical Analysis
- Geophysics and Sensor Technology
- Scientific Measurement and Uncertainty Evaluation
European Southern Observatory
2016-2024
European Southern Observatory
2019-2021
Observatoire de Paris
2020
Sorbonne Université
2020
Université Grenoble Alpes
2020
Centre National de la Recherche Scientifique
2020
Laboratoire d’études spatiales et d’instrumentation en astrophysique
2020
Université Paris Cité
2020
Université Libre de Bruxelles
2014-2018
Michigan United
2018
Context. β Pictoris is arguably one of the most studied stellar systems outside our own. Some 30 yr observations have revealed a highly-structured circumstellar disk, with rings, belts, and giant planet: b. However very little known about how this system came into being. Aims. Our objective to estimate C/O ratio in atmosphere b obtain an dynamical mass planet, as well refine its orbital parameters using high-precision astrometry. Methods. We used GRAVITY instrument four 8.2 m telescopes Very...
We present K-band interferometric observations of the PDS 70 protoplanets along with their host star using VLTI/GRAVITY. obtained spectra and 100 $\mu$as precision astrometry both b c in two epochs, as well spatially resolving hot inner disk around star. Rejecting unstable orbits, we found a nonzero eccentricity for $0.17 \pm 0.06$, near-circular orbit c, an orbital configuration that is consistent planets migrating into 2:1 mean motion resonance. Enforcing dynamical stability, 95% upper...
Methods used to detect giant exoplanets can be broadly divided into two categories: indirect and direct. Indirect methods are more sensitive planets with a small orbital period, whereas direct detection is orbiting at large distance from their host star. %, thus on long period. This dichotomy makes it difficult combine the techniques single target once. Simultaneous measurements made by offer possibility of determining mass luminosity method testing formation models. Here, we aim show how...
Aims. We aim to demonstrate that the presence and mass of an exoplanet can now be effectively derived from astrometry another exoplanet. Methods. combined previous β Pictoris b with a new set observations GRAVITY interferometer. The orbital motion is fit using Markov chain Monte Carlo simulations in Jacobi coordinates. inner planet, c, was also reobserved at separation 96 mas, confirming estimations. Results. From planet only, we (i) detect c (ii) constrain its 10.04 −3.10 +4.53 M Jup . If...
Context:Optical interferometry is at a key development stage. ESO's VLTI has established stable, robust infrastructure for long-baseline general astronomical observers. The present second-generation instruments offer wide wavelength coverage and improved performance. Their sensitivity measurement accuracy lead to data images of high reliability. Aims:We have developed MATISSE, the Multi AperTure mid-Infrared SpectroScopic Experiment, access resolution imaging in spectral domain explore...
With four companions at separations from 16 to 71 au, HR 8799 is a unique target for direct imaging, presenting an opportunity the comparative study of exoplanets with shared formation history. Combining new VLTI/GRAVITY observations obtained within ExoGRAVITY program archival data, we perform systematic atmospheric characterisation all planets. We explore different levels model flexibility understand temperature structure, chemistry and clouds each planet using both petitRADTRANS retrievals...
Spectro-seismic measurements of red giants enabled the recent discovery stars in thick disk that are more massive than 1.4 M_sun. While it has been claimed most these younger rest typical stars, we show evidence they might be products mass transfer binary evolution, notably evolved blue stragglers. We took new radial velocities a sample 26 from APOKASC, including 13 "young" and "old" with similar stellar parameters but masses below 1.2 M_sun found appear to systems respect stars....
Aims. HD 206893 is a nearby debris disk star that hosts previously identified brown dwarf companion with an orbital separation of ∼10 au. Long-term precise radial velocity (RV) monitoring, as well anomalies in the system proper motion, has suggested presence additional, inner system. Methods. Using information from ongoing precision RV measurements HARPS spectrograph, Gaia host astrometry, we have undertaken multi-epoch search for purported additional planet using VLTI/GRAVITY instrument....
We have mapped the 12CO(3–2) line emission around Mira AB system at 0.̋5 resolution using Atacama Large Millimeter/submillimeter Array (ALMA). The CO map shows amazing complexity. circumstellar gas has been shaped by different dynamical actors during evolution of system, and several morphological components can be identified. companion is marginally resolved in continuum currently 0.̋487 ± 0.̋006 separation. In main component, centered on stellar velocity, spiral arcs A are found. appears to...
Context. The nearby and young β Pictoris system hosts a well resolved disk, directly imaged massive giant planet orbiting at ≃9 au, as an inner ≃2.7 which was recently detected through radial velocity (RV). As such, it offers several unique opportunities for detailed studies of planetary formation early evolution. Aims. We aim to further constrain the orbital physical properties b c using combination high contrast imaging, long base-line interferometry, RV data. also predict closest...
Context. Since 2019, GRAVITY has provided direct observations of giant planets and brown dwarfs at separations down to 95 mas from the host star. Some these have first confirmation companions previously detected by indirect techniques (astrometry radial velocities). Aims. We want improve observing strategy data reduction in order lower inner working angle dual-field on-axis mode. also determine current limitations instrument when faint with 30–150 range. Methods. To angle, we propose a fiber...
Context. Stellar convection plays an important role in atmospheric dynamics, wind formation, and the mass-loss processes asymptotic giant branch stars. However, a direct characterization of convective surface structures terms size, contrast, lifespan is quite challenging, as spatially resolving these features requires highest angular resolution. Aims. We aim to characterize size on O-rich AGB star R Car test different theoretical predictions based mixing-length theory from solar models....
We present near-infrared interferometry of the carbon-rich asymptotic giant branch (AGB) star R Sculptoris. The visibility data indicate a broadly circular resolved stellar disk with complex substructure. observed AMBER squared values show drops at positions CO and CN bands, indicating that these lines form in extended layers above photosphere. are best fit by model without wind. PIONIER consistent same model. obtain Rosseland angular diameter 8.9+-0.3 mas, corresponding to radius 355+-55...
Context. The S-type asymptotic giant branch (AGB) star π1 Gru has a known companion at separation of 2.̋7 (≈400 AU). Previous observations the circumstellar envelope (CSE) show strong deviations from spherical symmetry. structure, including an equatorial torus and fast bipolar outflow, is rarely seen in AGB phase particularly unexpected such wide binary system. Therefore second, closer been suggested, but evidence not conclusive.
Context. Near-infrared interferometry has become a powerful tool for studying the orbital and atmospheric parameters of substellar companions. Aims. We aim to reveal nature reddest known companion HD 206893 B by its near-infrared colors spectral morphology investigating motion. Methods. fit models giant planets brown dwarfs perform retrievals with petitRADTRANS ATMO on observed GRAVITY, SPHERE, GPI spectra B. To recover unusual features, first foremost extremely red color, we include...
Abstract Young, low-mass brown dwarfs orbiting early-type stars, with low mass ratios ( q ≲ 0.01), appear to be intrinsically rare and present a formation dilemma: could handful of these objects the highest-mass outcomes “planetary” channels (bottom up within protoplanetary disk), or are they more representative lowest-mass “failed binaries” (formed via disk fragmentation core fragmentation)? Additionally, their orbits can yield model-independent dynamical masses, when paired wide wavelength...
Context . Dual-field interferometric observations with VLTI/GRAVITY sometimes require the use of a binary calibrator. This is star whose individual components remain unresolved by interferometer, separation between 400 and 2000 mas for Unit Telescopes (UTs), or 1200–3000 Auxiliary (ATs). The vector also needs to be predictable within 10 proper pointing instrument. Aims No list properly vetted calibrators was available so far dual-field on UTs. Our objective compile such make it community....
Aims. The circumstellar environment of L2 Pup, an oxygen-rich semiregular variable, was observed to understand the evolution mass loss and shaping ejecta in late stages stellar evolution.
We study the circumstellar environment of carbon-rich star R Scl using near- and mid-infrared high spatial resolution observations from ESO-VLTI instruments VINCI MIDI. These aim at increasing our knowledge dynamic processes in play within very close where mass loss AGB stars is initiated. Data are interpreted a self-consistent model. Interferometric do not show any significant variability effect 16 m baseline between phases 0.17 0.23 K band, for both 15 0.66 0.97 31 0.90 N band. find fairly...
Modeling stellar atmospheres is a complex, intriguing task in modern astronomy. A systematic comparison of models with multi-technique observations the only efficient way to constrain them. Aims: We performed self-consistent modeling six C-rich AGB stars: R Lep, Vol, Y Pav, AQ Sgr, U Hya and X TrA, aim enlarging knowledge dynamic processes occurring their atmospheres. Methods. used VLTI/MIDI interferometric observations, combination spectro-photometric data, compared them Results: The can...