A5054347381- Astro and Planetary Science
- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Astrophysical Phenomena and Observations
- Solar and Space Plasma Dynamics
- Astronomy and Astrophysical Research
- Spacecraft and Cryogenic Technologies
- Astronomical Observations and Instrumentation
- Space Exploration and Technology
- High-pressure geophysics and materials
- Chronic Obstructive Pulmonary Disease (COPD) Research
- Optical Imaging and Spectroscopy Techniques
- Pulsars and Gravitational Waves Research
- Isotope Analysis in Ecology
- Geophysics and Gravity Measurements
- Blind Source Separation Techniques
- Spectroscopy Techniques in Biomedical and Chemical Research
- Gamma-ray bursts and supernovae
- Infrared Thermography in Medicine
Osservatorio Astronomico di Palermo
2016-2024
Laboratoire d’Etudes du Rayonnement et de la Matière en Astrophysique et Atmosphères
2019
CY Cergy Paris Université
2019
Sorbonne Université
2019
Centre National de la Recherche Scientifique
2019
National Institute for Astrophysics
2019
University of Palermo
2019
Politecnico di Milano
2019
Expanding the number of hot giant planets with atmospheric characterisation can improve our understanding their atmospheres as well formation and evolution mechanisms. In this work, we use high-resolution spectroscopy in near-infrared (NIR) to search for chemical signatures two Jupiters KELT-8 b KELT-23 Ab, perform a first properties. We measured transmission spectrum each target NIR spectrograph GIANO-B at TNG searched signals by cross-correlating data synthetic spectra. order characterise...
Hot Jupiters are among the most suitable targets for atmospheric studies. Expanding number of hot gaseous giant planets with characterisations can improve our understanding chemical-physical properties their atmospheres, as well formation and evolution these extreme planets. In this work, we use high-resolution spectroscopy in near-infrared (NIR) to search chemical signatures atmosphere two KELT-8,b eq K) KELT-23,Ab =1,561±20,K) present a first characterisation properties. We measured...
Context. The intrinsic variability due to the magnetic activity of young active stars is one main challenges in detecting and characterising exoplanets. stellar responsible for jitter effects observed both photometric spectroscopic observations that can impact our planetary detection sensitivity. Aims. We present a method able model photosphere its surface inhomogeneities (starspots) young, active, fast-rotating based on cross-correlation function (CCF) technique, we extract information...
Impulsive short term variations occur in all kinds of solar-type stars. They are the results complex phenomena such as stellar magnetic field reconnection, low-level variability or some cases even star-planet interactions. The radiation arising from these events is often highly energetic and, stars hosting planets, may interact with planetary atmospheres. Studying rate fundamental to understand their role modifying chemical composition or, extreme cases, disruption Here, we present a new...
Classical T Tauri stars (CTTSs) are young low-mass stellar objects accreting mass from their circumstellar disks. They characterized by high levels of coronal activity as revealed X-ray observations. This may affect the disk stability and environment. Here we investigate if an intense due to flares occurring close accretion perturb inner stability, disrupt part and, possibly, trigger phenomena with rates comparable those observed. We model a magnetized protostar surrounded through 3D...
Context. The accretion process in Classical T Tauri Stars (CTTSs) can be studied through the analysis of some UV and X-ray emission lines which trace hot gas flows act as diagnostics post-shock downfalling plasma. In band, where higher spectral resolution is available, these are characterized by rather complex profiles whose origin still not clear. Aims. We investigate at impact regions density structured (fragmented) streams.We study if how stream fragmentation resulting structure region...
Abridged. We observed the 40 Myr old star DS Tuc A with XMM-Newton and recorded two X-ray bright flares, second event occurring about 12 ks after first one. Their duration from rise to end of decay was 8-10 in soft X-rays (0.3-10 keV). The flares were also band 200-300 nm UVM2 filter Optical Monitor. UV 3 ks. delay between peak is a probe heating phase followed by evaporation increase density emission measure flaring loop. coronal plasma temperature at flare peaks reached 54-55 MK....
Context . Several studies suggest that the emission properties of a star can be significantly affected by its interaction with nearby planet through magnetic fields or between their respective winds. However, actual observability these effects remains subject debate. An illustrative example is HD 189733A system: certain characteristics emissions have been interpreted as indicative ongoing interactions and associated planet. Other attribute to coronal activity star. Aims In this study we...
Active region evolution plays an important role in the generation and variability of magnetic fields on surface lower main-sequence stars. However, determining lifetime active growth decay as well their is a complex task. We aim to test whether for shows any dependency stellar parameters. identify sample stars with well-defined ages via kinematics. made use high-resolution spectra compute rotational velocities, activity levels, emission excesses. these data revisit activity-rotation-age...
Models and observations indicate that the impact of matter accreting onto surface young stars produces regions at base accretion columns, in which optically thin thick plasma components coexist. Thus an accurate description these impacts requires to account for effects absorption emission radiation. We study radiation emerging from shock-heated on structure pre-shock downfalling material. investigate if a significant occurs it leads heating gas. developed hydrodynamics model describing...
Modeling the dynamics of most astrophysical structures requires an adequate description radiation-matter interaction. Several numerical (magneto)hydrodynamics codes were upgraded with a radiation module to fulfill this request. However, those among them that use either flux-limited diffusion (FLD) or M1 moment approaches are restricted local thermodynamic equilibrium (LTE). This assumption may be not valid in some cases. We present version LTE radiation-hydrodynamics implemented PLUTO code,...
X-rays emitted by the coronae of solar-type stars are a feature present in up to late-A types during main sequence phase. F stars, either with or without hot Jupiters, usually X-ray emitters. The very low level emission F5 star WASP-18 despite its relatively young age and spectral type is thus quite peculiar. [Abridged] We observed KELT-24 \xmm\ for total 43 ks order test if activity this depressed interaction massive Jupiter, as case WASP-18. detected combined EPIC images high significance...
Several studies suggest that the emission properties of a star can be affected by its interaction with nearby planet. However, actual observability these effects remains subject debate. An example is HD189733A system, where some characteristics emissions have been interpreted as indicative ongoing interactions between and Other attribute to coronal activity star. In this work, we investigate whether observed stellar X-ray flare events, which appear in phase planetary period could attributed...
Context . HAT-P-67 b is one of the lowest-density gas giants known to date, making it an excellent target for atmospheric characterisation through transmission spectroscopy technique. Aims In framework GAPS large programme, we collected four transit events with aim studying exoplanet atmosphere and deriving orbital projected obliquity. Methods We exploited high-precision GIARPS (GIANO-B + HARPS-N) observing mode Telescopio Nazionale Galileo (TNG) along additional archival TESS photometry...
We examined in depth the star BD+00 444 (GJ 105.5, TOI-2443; V = 9.5 mag; d 23.9 pc), with aim of characterizing and confirming planetary nature its small companion, planet candidate TOI-2443.01, which was discovered by TESS. monitored HARPS-N spectrograph for 1.5 years to search planet-induced radial-velocity (RV) variations, then analyzed RV measurements jointly TESS ground-based photometry. determined that host is a quiet K5 V, we revealed sub-Neptune b has radius $R_b=2.36\pm0.05...
Context. Massive substellar companions orbiting active low-mass stars are rare. They, however, offer an excellent opportunity to study the main mechanisms involved in formation and evolution of objects. Aims. We aim unravel physical nature transit signal observed by TESS space mission on M dwarf TOI-5375. Methods. analysed available photometric data as well high-resolution (R $\sim$ 115000) HARPS-N spectra. combined these characterise star TOI-5375 disentangle signals related stellar...
Abstract Hot Jupiters (HJs) are massive gaseous planets orbiting close to their host stars. Due physical characteristics and proximity the central star, HJs natural laboratories study process of stellar‐planet interaction (SPI). Phenomena related SPI may include inflation evaporation planetary atmospheres, formation cometary tails bow shocks magnetospheric between magnetic field planet that star. Several works suggest some systems show enhanced stellar activity in phase with rotation period....
Abstract The study of young planetary systems is great importance for understanding their formation and evolution. Therefore, today, a effort placed on the observation modeling such systems. Of course, planets do not evolve in isolation, but behavior depends host star environment which they are embedded. In particular, we know that at ages, solar‐type stars much more active than sun‐age with all phenomena this involves, including strong emission high energies, from ultraviolet (UV) to...
The intrinsic variability due to the magnetic activity of young active stars is one main challenges in detecting and characterising exoplanets. We present a method able model stellar photosphere its surface inhomogeneities (starspots) young/active fast-rotating stars, based on cross-correlation function (CCF) technique, extract information about spot configuration star. Within Global Architecture Planetary Systems (GAPS) Project at Telescopio Nazionale Galileo, we analysed more than 300...