R. Silvotti
A5069138705- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astronomical Observations and Instrumentation
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Gamma-ray bursts and supernovae
- Adaptive optics and wavefront sensing
- Pulsars and Gravitational Waves Research
- Geophysics and Gravity Measurements
- Astrophysical Phenomena and Observations
- Galaxies: Formation, Evolution, Phenomena
- Calibration and Measurement Techniques
- High-pressure geophysics and materials
- Particle Accelerators and Free-Electron Lasers
- Superconducting Materials and Applications
- Algebraic structures and combinatorial models
- Advanced Algebra and Geometry
- Solar and Space Plasma Dynamics
- History and Developments in Astronomy
- Particle accelerators and beam dynamics
- Nonlinear Waves and Solitons
- Atmospheric Ozone and Climate
- Scientific Research and Discoveries
- Geological and Geophysical Studies
- Astrophysics and Cosmic Phenomena
Osservatorio Astrofisico di Torino
2015-2024
National Institute for Astrophysics
2003-2019
Institute for Space Astrophysics and Planetology
2013
Astronomical Observatory of Capodimonte
2000-2012
Max Planck Institute for Solar System Research
2011
University of Göttingen
2011
Konkoly Observatory
2011
Hungarian Academy of Sciences
2011
KU Leuven
2011
Netherlands Institute for Radio Astronomy
2006
The Transiting Exoplanet Survey Satellite (TESS) will be conducting a nearly all-sky photometric survey over two years, with core mission goal to discover small transiting exoplanets orbiting nearby bright stars. It obtain 30-minute cadence observations of all objects in the TESS fields view, along 2-minute 200,000 400,000 selected choice which stars observe at 2-min is driven by need detect planets, leads selection primarily bright, cool dwarfs. We describe catalogs assembled and algorithms...
We present results from the first two quarters of a survey to search for pulsations in compact stellar objects with Kepler spacecraft. The sample and various methods applied its compilation are described, spectroscopic observations presented separate into accurate classes. From photometry we clearly identify nine pulsators, number interesting binary stars. Of one shows strong, rapid typical V361 Hya type sdB variable (sdBV), seven show long-period characteristic V1093 Her sdBVs,...
The Kepler Mission has acquired 33.5 d of continuous 1-min photometry KPD 1946+4340, a short-period binary system that consists subdwarf B star (sdB) and white dwarf. In the light curve, eclipses are clearly seen, with deepest occurring when compact dwarf crosses disc sdB (0.4 per cent) more shallow ones (0.1 As expected, is deformed by gravitational field dwarf, which produces an ellipsoidal modulation curve. Spectacularly, very strong Doppler beaming (also known as boosting) effect also...
A long-term multi-purpose observational programme has started with HARPS-N@TNG aimed to characterise the global architectural properties of exoplanetary systems. In this first paper we fully transiting system Qatar-1. We exploit HARPS-N high-precision radial velocity measurements obtained during a transit measure Rossiter-McLaughlin effect in Qatar-1 system, and out-of-transit redetermine spectroscopic orbit. New photometric light-curves are analysed characterisation host star atmospheric...
A low-mass planet around a white dwarf Numerous exoplanets have been detected Sun-like stars. These stars end their lives as dwarfs, which should inherit any surviving planetary systems. Manser et al. found periodic shifts in emission lines from disc of gas orbiting (see the Perspective by Fossati). They used numerical simulations to show that most likely explanation for spectral is within disc. The must be unusually small and dense avoid being ripped apart tidal forces. authors speculate it...
Aims: Our scientific goal is to provide revised membership lists of the Alpha Per, Pleiades, and Praesepe clusters exploiting second data release Gaia produce five-dimensional maps (ra, dec, parallax, pmRA, pmDEC) these clusters. Methods: We implemented kinematic method combined with statistical treatment parallaxes proper motions identify astrometric member candidates three most nearby best studied open in sky. Results: cross-correlated catalogue large-scale public surveys complement...
We present the first results of our analyses selected RR Lyrae stars for which data have been obtained by Kepler Mission. As expected, we find a significant fraction RRab to show Blazhko effect, still unexplained phenomenon that manifests itself as periodic amplitude and phase modulations light curve, on time scales typically tens hundreds days. The long span Mission 3.5 yrs, unprecedentedly high precision its provide unique opportunity study stars. Using modulated star observed in roll...
Context. Contemporary high precision photometry from space provided by the Kepler and CoRoT satellites generates significant breakthroughs in terms of exploiting long-period, g-mode pulsating hot B subdwarf (sdBVs) stars with asteroseismology.
Aims. We observed the $\tau$ Boo system with HARPS-N spectrograph to test a new observational strategy aimed at jointly studying asteroseismology, planetary orbit, and star-planet magnetic interaction. Methods. collected high-cadence observations on 11 nearly consecutive nights for each night averaged raw FITS files using dedicated software. In this way we obtained spectra high signal-to-noise ratio, used study variation of CaII H&K lines have radial velocity values free from stellar...
We present a spectroscopic survey of 230 white dwarf candidates within 40 pc the Sun from William Herschel Telescope and Gran Telescopio Canarias. All were selected $\textit{Gaia}$ Data Release 2 (DR2) in almost all cases had no prior classifications. find total 191 confirmed dwarfs 39 main-sequence star contaminants. The majority stellar remnants sample are relatively cool ($\langle T_{\rm eff} \rangle$ = 6200 K), showing either hydrogen Balmer lines or featureless spectrum, corresponding...
We present a spectroscopic survey of 248 white dwarf candidates within 40 pc the Sun; these 244 are in southern hemisphere. Observations were performed mostly with Very Large Telescope (X-Shooter) and Southern Astrophysical Research Telescope. Almost all selected from $\textit{Gaia}$ Data Release 3 (DR3). find total 246 confirmed dwarfs, 209 which had no previously published spectra, two main-sequence star contaminants. Of these, 100 dwarfs display hydrogen Balmer lines, 69 have featureless...
CSL-1 (Capodimonte--Sternberg--Lens Candidate, No.1) is an extragalactic double source detected in the OAC-DF (Osservatorio Astronomico di Capodimonte - Deep Field). It can be interpreted either as chance alignment of two identical galaxies at z=0.46 or first case gravitational lensing by a cosmic string. Extensive modeling shows fact that strings are only type lens which (at least low angular resolution) produce undistorted images background source. We propose experimentum crucis to...
We present a seismic analysis of the pulsating hot B subdwarf KPD 1943+4058 (KIC 005807616) on basis long-period, gravity-mode pulsations recently uncovered by Kepler. This is first time that g-mode seismology can be exploited quantitatively for stars extreme horizontal branch, all previous successful analyses having been confined so far to short-period, p-mode pulsators. demonstrate current models subdwarfs quite well explain observed periods, while being consistent with independent...
We present our analyses of 15 months Kepler data on KIC 10139564. detected 57 periodicities with a variety properties not previously observed all together in one pulsating subdwarf B (sdB) star. Ten the were found low-frequency region, and we associate them nonradial g modes. The other high-frequency which are likely p discovered that most components multiplets common spacing. Assuming caused by rotation, derive rotation period 25.6 ± 1.8 d. also allow us to identify pulsations an...
We present results from the final six months of a survey to search for pulsations in white dwarfs and hot subdwarf stars with Kepler spacecraft. Spectroscopic observations are used separate objects into accurate classes, we explore physical parameters B (sdB) sample. From photometry our spectroscopic data, find that sample contains 5 new pulsators V1093 Her type, one AM CVn type cataclysmic variable, number other binary systems. This completes compact Kepler. No V361 Hya short-period...
Our scientific goal is to provide a 3D map of the nearest open cluster Sun, Hyades, combining recent release Gaia astrometric data, ground-based parallaxes sub-stellar member candidates and photometric data from surveys which cover large areas cluster. We combined second with H-band obtained infrared camera on 2-m robotic Liverpool telescope astrometrically identify stellar members Sun. find 1764 objects within 70 degree radius center release, whose kinematic properties are consistent...
We performed an intensive radial velocity monitoring of XO-2S, the wide companion transiting planet-host XO-2N, using HARPS-N at TNG in framework GAPS programme. The measurements indicate presence a new planetary system formed by planet that is slightly more massive than Jupiter 0.48 au and Saturn-mass 0.13 au. Both orbits are moderately eccentric were found to be dynamically stable. There also indications long-term trend velocities. This first confirmed case binary whose components both...
XO-2 is the first confirmed wide stellar binary system where almost twin components XO-2N and XO-2S have planets. This stimulated a detailed characterization study of planetary based on new observations. We collected high-resolution spectra with HARPS-N spectrograph multi-band light curves. Spectral analysis led to an accurate determination atmospheric parameters activity. 14 transit curves XO-2Nb used improve parameters. Photometry provided magnitude differences between stars measure their...