A5091196642- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Solar and Space Plasma Dynamics
- Astrophysics and Cosmic Phenomena
- Astro and Planetary Science
- Gamma-ray bursts and supernovae
- Dark Matter and Cosmic Phenomena
- Astronomy and Astrophysical Research
- Neutrino Physics Research
- Astronomical Observations and Instrumentation
- Geophysics and Gravity Measurements
- Particle Detector Development and Performance
- Astrophysical Phenomena and Observations
- Particle accelerators and beam dynamics
- Magnetic confinement fusion research
- Radio Astronomy Observations and Technology
- Pulsars and Gravitational Waves Research
- Ionosphere and magnetosphere dynamics
- Particle physics theoretical and experimental studies
- Atomic and Molecular Physics
- CCD and CMOS Imaging Sensors
- Laser-induced spectroscopy and plasma
- History and Developments in Astronomy
- Radiation Detection and Scintillator Technologies
- Adaptive optics and wavefront sensing
Istituto Nazionale di Fisica Nucleare, Sezione di Catania
2021-2025
Osservatorio Astrofisico di Catania
2013-2024
University of Florence
2022-2024
University of Rome Tor Vergata
2024
TU Dortmund University
2023
University of Łódź
2023
Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas
2023
University of Turku
2023
Niels Brock
2023
University of Copenhagen
2023
Switchbacks are sudden, large radial deflections of the solar wind magnetic field, widely revealed in interplanetary space by Parker Solar Probe. The switchbacks' formation mechanism and sources still unresolved, although candidate mechanisms include Alfv\'enic turbulence, shear-driven Kelvin-Helmholtz instabilities, interchange reconnection, geometrical effects related to spiral. This Letter presents observations from Metis coronagraph onboard Orbiter a single propagating S-shaped vortex,...
In this paper, we present the analysis of incoherent non-thermal radio emission from a sample hot magnetic stars, ranging early-B to early-A spectral type. Spanning wide range stellar parameters and wind properties, these stars display commonality in their which presents new challenges scenario as originally conceived. It was thought that relativistic electrons, responsible for emission, originate current sheets formed where opens field lines. However, true mass-loss rates cooler are too...
ABSTRACT CO Cam (TIC 160268882) is the second ‘single-sided pulsator’ to be discovered. These are stars where one hemisphere pulsates with a significantly higher amplitude than other side of star. binary star comprised an Am δ Sct primary Teff = 7070 ± 150 K, and spectroscopically undetected G main-sequence secondary The dominant pulsating centred on L1 point. We have modelled spectral energy distribution combined radial velocities, independently TESS light curve velocities. Both these give...
Context. We present the results for in-flight radiometric calibration performed Visible Light (VL) channel of Metis coronagraph on board Solar Orbiter. Aims. The is a fundamental step in building official pipeline instrument, devoted to producing calibrated data physical units (L2 data). Methods. To obtain factor ( ϵ VL ), we used stellar targets transiting field view. derived by determining signal each star means aperture photometry and calculating its expected flux band pass. analyzed set...
ABSTRACT The Catania Astrophysical Observatory Spectropolarimeter (CAOS) is a white-pupil cross-dispersed échelle spectrograph with spectral resolution of up to R = 55,000 in the 375–1100 nm range single exposure, complete coverage 856 nm. CAOS linked 36-inch telescope, at Mount Etna Observatory, couple 100 μ m optical fibers and it achieves signal-to-noise ratio better than 60 for V 10 mag star one hour. thermally stabilized temperature within 0.01 K rms, so that radial velocities are...
ABSTRACT Magnetic chemically peculiar stars of the main sequence can present rotational periods as long many decades. Here we report results an observational campaign started in 2001 aimed at establishing these very from variability integrated magnetic field modulus, so-called surface Bs, measured Zeeman splitting Fe ii 6149.258 Å spectral line. 36 have been monitored with various high-resolution spectrographs different telescopes, totalling 412 newly collected spectra. To improve phase...
Abstract This Letter reports the first observational estimate of heating rate in slowly expanding solar corona. The analysis exploits simultaneous remote and local observations same coronal plasma volume, with Solar Orbiter/Metis Parker Probe instruments, respectively, relies on basic wind magnetohydrodynamic equations. As expected, energy losses are a minor fraction flux, since most dissipation that feeds acceleration flow occurs much closer to Sun than heights probed present study, which...
Context. Blazars are astrophysical sources whose emission is dominated by non-thermal processes, i.e. synchrotron and inverse Compton emission. Although the general picture rather robust consistent with observations, many aspects still unexplored.
Magnetized plasmas in compact trap may become experimental environments for the investigation of nuclear β-decays astrophysical interest. In framework project PANDORA (Plasmas Astrophysics, Nuclear Decays Observation and Radiation Archaeometry) research activities are devoted to demonstrate feasibility an experiment aiming at correlating radionuclides lifetimes in-plasma ions charge state distribution (CSD). The paper describes multidiagnostics setup now available INFN-LNS, which allows...
We present new ATCA multi-wavelength radio measurements (range 2.1-21.2 GHz) of the early-type magnetic star rho Oph A, performed in March 2019 during 3 different observing sessions. These observations evidence a clear rotational modulation stellar emission and detection coherent auroral from A at 2.1 GHz. collected high-resolution optical spectra acquired by several instruments over time span about ten years. also report field that, together with light curves temporal variation equivalent...
Abstract Recently, we performed a complete study of the SB2 system HD 161701 with an orbital period 12.5 d, consisting HgMn primary and classical Ap secondary. Since this is first identified particular combination peculiar stars, presence magnetic field in both components considerable interest to astronomers studying stellar magnetism impact binary systems. Apart from 161701, only one other close systems component, 98088, currently known. Using high accuracy radial velocity planet searcher...
The {\it Kepler} space mission and its K2} extension provide photometric time series data with unprecedented accuracy. These challenge our current understanding of the metallic-lined A stars (Am stars) for what concerns onset pulsations in their atmospheres. It turns out that predictions diffusion models do not agree observations. To understand this discrepancy, it is crucial importance to obtain ground-based spectroscopic observations Am fields order determine best estimates stellar...
We present light curves and periodograms for 27 stars in the young Upper Scorpius association (age = 11 ± 1 Myr) obtained with Kepler spacecraft. This is only second stellar grouping to host several pulsating pre-main-sequence (PMS) which have been observed from space. From an analysis of periodograms, we identify six δ Scuti variables one γ Doradus star. These are most likely PMS or else very close zero-age main sequence. Four were short-cadence mode, allows us resolve entire frequency...
In this paper, we present a multi-instrument analysis of the mercury-manganese star HD 49606. New spectroscopic observations have been obtained by us with Catania Astrophysical Observatory Spectropolarimeter (CAOS@OAC) and High Accuracy Radial Velocity Planet Searcher-North@Telescopio Nazionale Galileo (HARPS-N@TNG). Combining these archive data coming from other instruments, performed comprehensive star. We highlight motion around centre mass binary system SB1 type, calculate fundamental...
In this paper, we present the results of a spectroscopic campaign devoted to ascertain actual nature sample 155 objects reported as uncertain peculiar stars in General catalogue Ap, Am, and HgMn stars. Spectroscopic observations have been obtained with Catania Astrophysical Observatory Spectropolarimeter. We derive for all that appear be single stars, effective temperature, gravity, rotational radial velocities, chemical abundances by spectral synthesis method, then using an abundance-based...
The non-thermal radio emission of main-sequence early-type stars is a signature stellar magnetism. We present multi-wavelength (1.6-16.7 GHz) ATCA measurements the magnetic star rho OphC, which flat-spectrum source. OphC partially circularly polarized with steep spectral dependence: fraction about 60% at lowest frequency sub-band (1.6 while undetected 16.7 GHz. This clear evidence coherent Auroral Radio Emission (ARE) from magnetosphere. Interestingly, detection OphC's ARE not related to...
Abstract Direct measurements of stellar magnetic fields are based on the splitting spectral lines into polarized Zeeman components. With a few exceptions, signatures hidden in data noise, and number methods have been developed to measure average, over visible disk, longitudinal components field. At present, faint stars only observable via low-resolution spectropolarimetry, which is method regression Stokes V signal against first derivative I . Here, we present an extension this obtain direct...
Stock 2 is a little-studied open cluster that shows an extended main-sequence turnoff (eMSTO). In order to investigate this phenomenon and characterise the itself we performed high-resolution spectroscopy in framework of Stellar Population Astrophysics (SPA) project. We employed High Accuracy Radial velocity Planet Searcher North hemisphere spectrograph (HARPS-N) at Telescopio Nazionale Galileo (TNG). completed our observations with additional spectra taken Catania Astrophysical Observatory...
The pulsating eclipsing binaries are remarkable systems that provide an opportunity to probe the stellar interior and determine fundamental parameters precisely. Especially detached binary with (a) component(s) significant objects understand nature of oscillations since effects in these negligible. Recent studies based on space data have shown pulsation mechanisms some oscillating stars not completely understood. Hence, comprehensive a number within important. In this study, we present...
Context. In recent years, HgMn stars have attracted attention after in several of them surface chemical spots different elements were discovered, whose origin and possible connection with binarity magnetic fields is not clear yet.
A method for the determination of integrated longitudinal stellar fields from low-resolution spectra is so-called slope method, which based on regression Stokes V signal against first derivative I. Here we investigate possibility to extend this technique measure magnetic cool stars high resolution spectra. For purpose developed a multi-line modification called method. We tested by analysing synthetic computed with COSSAM code and real observations obtained spectropolarimeters Narval,...
Abstract We describe a new polarimetric facility available at the Istituto Nazionale di AstroFisica / Telescopio Galileo La Palma, Canary islands. This facility, PAOLO (Polarimetric Add‐On for LRS Optics), is located Nasmyth focus of an alt‐az telescope and requires specific modeling in order to remove time‐ pointing position‐dependent instrumental polarization. also opto‐mechanical structure instrument its calibration present early examples applications. (© 2014 WILEY‐VCH Verlag GmbH &...
ABSTRACT In this paper, we present the results of a spectroscopic campaign devoted to ascertaining actual nature sample five objects reported as chemically peculiar stars in Catalogue Ap, HgMn and Am (2009, A&A, 498, 961). Spectroscopic observations were obtained with Catania Astrophysical Observatory Spectropolarimeter. For each objects, derive effective temperature, gravity, rotational radial velocities, chemical abundances using spectral synthesis method. All targets found be SB1...
Magnetoplasmas in ECR-Ion Sources are excited from gaseous elements or vapours by microwaves the range 2.45–28 GHz via Electron Cyclotron Resonance. A B-minimum, magnetohydrodynamic stable configuration is used for trapping plasma. The values of plasma density, temperature and confinement times typically ne= 1011−1013 cm−3, 01 eV<Te<10 keV, 0.001<tc<1 s. At INFN-LNS several diagnostics tools have been developed probing electromagnetic emission such plasmas, optical/X-ray domain. Fast Silicon...
Electron Cyclotron Resonance (ECR) plasmas with high density and temperature are required by the injectors for Accelerators interdisciplinary studies in Astrophysics Nuclear Astrophysics. Understanding further developing magnetic traps requires accurate measurements of physical properties confined plasma, such as density, ionization state, not allowed commonly used diagnostic methods (imaging, low resolution spectroscopy). Here, we show potentiality a few applications spectroscopy visible...