A5077623562- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astro and Planetary Science
- Astrophysics and Star Formation Studies
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Geophysics and Gravity Measurements
- Scientific Computing and Data Management
- Space Exploration and Technology
- Adaptive optics and wavefront sensing
- Neural Networks and Applications
- Archaeology and ancient environmental studies
- Evolutionary Algorithms and Applications
- Scientific Research and Discoveries
University of Bologna
2021-2024
Aarhus University
2019-2024
University of Birmingham
2023-2024
Osservatorio di Astrofisica e Scienza dello Spazio
2022-2023
National Institute for Astrophysics
2023
Netherlands Institute for Radio Astronomy
2023
We present the discovery of TOI-197.01, first transiting planet identified by Transiting Exoplanet Survey Satellite (TESS) for which asteroseismology host star is possible. TOI-197 (HIP116158) a bright (V=8.2 mag), spectroscopically classified subgiant oscillates with an average frequency about 430 muHz and displays clear signature mixed modes. The oscillation amplitude confirms that redder TESS bandpass compared to Kepler has small effect on oscillations, supporting expected yield thousands...
Relics of ancient accretion events experienced by the Milky Way are predominantly located within stellar halo our Galaxy. However, debris from different objects display overlapping distributions in dynamical spaces, making it extremely challenging to properly disentangle their contribution build-up To shed light on this chaotic context, we initiated a program aimed at homogeneous chemical tagging local Way, focusing component retrograde motion, since is expected host large fraction stars...
Since the onset of `space revolution' high-precision high-cadence photometry, asteroseismology has been demonstrated as a powerful tool for informing Galactic archaeology investigations. The launch NASA TESS mission enabled seismic-based inferences to go full sky -- providing clear advantage large ensemble studies different Milky Way components. Here we demonstrate its potential investigating Galaxy by carrying out first asteroseismic study red giant stars observed TESS. We use sample 25...
The search for twins of the Sun and Earth relies on accurate characterization stellar exoplanetary parameters: i.e., ages, masses, radii. In modern era asteroseismology, parameters solar-like stars are derived by fitting theoretical models to observational data, which include measurements their oscillation frequencies, metallicity [Fe/H], effective temperature Teff. Combining this information with transit data furthermore yields corresponding exoplanets. While [Fe/H] Teff commonly stated a...
We introduce the public version of BAyesian STellar Algorithm (BASTA), an open-source code written in {\tt Python} to determine stellar properties based on a set astrophysical observables. BASTA has been specifically designed robustly combine large datasets that include asteroseismology, spectroscopy, photometry, and astrometry. describe number asteroseismic observations can be fit by how these combined with atmospheric (as well as parallaxes apparent magnitudes), making it most complete...
Metal-poor stars play a crucial role in understanding the nature and evolution of first stellar generation Galaxy. Previously, asteroseismic characterisation red-giant has relied on constraints from global parameters not full spectrum individual oscillation modes. Using latter, we present for time two evolved very metal-poor including detail-rich mixed-mode patterns. We will demonstrate that incorporating frequencies into grid-based modelling enhances its precision, enabling detailed studies...
Abstract The vast majority of Milky Way stellar halo stars were likely accreted from a small number (≲3) relatively large dwarf galaxy accretion events. However, the timing these events is poorly constrained and predominantly relies on indirect dynamical mixing arguments or imprecise age measurements associated with debris structures. Here, we aim to infer robust ages for galactic substructures more directly constrain merger history Galaxy. By combining kinematic, asteroseismic,...
We present a new asteroseismic analysis of the stars in Globular Cluster (GC) M4 based on data collected by K2 mission. report detection solar-like oscillation 37 stars, 32 red giant branch (RGB) and 6 horizontal (rHB) largest sample for this kind study GC up to date. Combining information from asteroseismology multi-band photometry we estimate both masses radii our targets. Our estimates are agreement with independent sources, serving as crucial verification low metallicity regime. As is an...
Abstract The bright star λ Ser hosts a hot Neptune with minimum mass of 13.6 M ⊕ and 15.5 day orbit. It also appears to be solar analog, mean rotation period 25.8 days surface differential very similar the Sun. We aim characterize fundamental properties this system constrain evolutionary pathway that led its present configuration. detect solar-like oscillations in time series photometry from Transiting Exoplanet Survey Satellite, we derive precise asteroseismic detailed modeling. obtain new...
ABSTRACT The Milky Way was shaped by the mergers with several galaxies in past. We search for remnant stars that were born these foreign and assess their ages an effort to put upper limits on merger times thereby better understand evolutionary history of our Galaxy. Using 5D-phase space information from Gaia eDR3, radial velocities DR2 chemical apogee DR16, we kinematically chemically select 21 red giant belonging former dwarf merged Way. With added asteroseismology Kepler K2 , determine ex...
Context. The origin of apparently young α -rich stars in the Galaxy is still a matter debate Galactic archaeology, whether they are genuinely or might be products binary evolution, and mergers mass accretion. Aims. Our aim to shed light on nature Milky Way by studying their distribution thanks an unprecedented sample giant that cover different regions have precise asteroseismic ages, chemical kinematic measurements. Methods. We analyzed new ∼6000 with ages coming from asteroseismology....
Asteroseismology is a powerful tool to infer fundamental stellar properties. The use of these asteroseismic-inferred properties in growing number astrophysical contexts makes it vital understand their accuracy. Consequently, we performed hare-and-hounds exercise where the hares simulated data for 6 artificial main-sequence stars and hounds inferred based on different inference procedures. To mimic pipeline such as that planned PLATO mission, all used same model grid. Some were using physics...
Robust age estimates of red giant stars are now possible thanks to the precise inference their mass based on asteroseismic constraints. However, there cases where such can be highly yet very inaccurate. An example is giants that have undergone loss or transfer events significantly altered mass. In this context, with "apparent" ages higher than Universe candidates as stripped stars, lost more expected, most likely via interaction a companion star, because poorly understood mass-loss mechanism...
Relics of ancient accretion events experienced by the Milky Way are predominantly located within stellar halo our Galaxy. However, debris from different objects display overlapping distributions in dynamical spaces, making it extremely challenging to properly disentangle their contribution build-up To shed light on this chaotic context, we started a program aimed at homogeneous chemical tagging local Way, focusing component retrograde motion, since is expected host large fraction stars...
Context. Abundances of slow neutron-capture process ( s -process) elements in stars with exquisite asteroseismic, spectroscopic, and astrometric constraints offer a novel opportunity to study stellar evolution, nucleosynthesis, Galactic chemical evolution. Aims. We investigate one the least studied -process literature, cerium (Ce), using asteroseismic from Kepler , K2, TESS missions. Methods. combined global parameters derived precise light curves obtained by missions abundances latest data...
ABSTRACT The Milky Way has distinct structural stellar components linked to its formation and subsequent evolution, but disentangling them is non-trivial. With the recent availability of high-quality data for a large numbers stars in Way, it natural next step research evolution Galaxy perform automated explorations with unsupervised methods structures hidden combination large-scale spectroscopic, astrometric, asteroseismic sets. We determine precise properties 21 076 red giants, mainly...
We present CARMA, the Cluster Ages to Reconstruct Milky Way Assembly project, aim of which is determine precise and accurate age measurements for entire system known Galactic globular clusters (GCs) use them trace most significant merger events experienced by Way. The strength CARMA relies on homogeneous photometry, theoretical isochrones, statistical methods, will enable us define a systematic uncertainty-free chronological scale complete sample GCs. In this paper, we describe framework in...
Context. Asteroseismic investigations of solar-like oscillations in giant stars allow for the derivation their masses and radii. For members open clusters, this allows us to obtain an age estimate cluster that is expected be identical given by colour-magnitude diagram, but independent uncertainties are present type analysis. Thus, a more precise accurate can obtained. Aims. We aim identify measure asteroseismic properties oscillating NGC 6866 utilise them estimate. Model comparisons also...
We present an in-depth analysis of the bright subgiant HR 7322 (KIC 10005473) using Kepler short-cadence photometry, optical interferometry from CHARA, high-resolution spectra SONG, and stellar modelling GARSTEC grids Bayesian grid-fitting algorithm BASTA. is only second with high-quality asteroseismology for which we also have interferometric data. find a limb-darkened angular diameter $0.443 \pm 0.007$ mas, which, combined distance derived parallax Gaia DR2 bolometric flux, yields linear...
The Transiting Exoplanet Survey Satellite (TESS) is recording short-cadence, high duty-cycle timeseries across most of the sky, which presents opportunity to detect and study oscillations in interesting stars, particular planet hosts. We have detected analysed solar-like bright G4 subgiant HD 38529, hosts an inner, roughly Jupiter-mass on a 14.3 d orbit outer, low-mass brown dwarf 2136 orbit. combine results from multiple stellar modelling teams produce robust asteroseismic estimates star's...
The analysis of the APOGEE data suggests existence a clear distinction between two sequences disc stars in [$\alpha$/Fe] vs. [Fe/H] abundance ratio space. We aim to test if two-infall chemical evolution models designed reproduce these solar neighbourhood are also capable predict bimodality observed vertical distribution [Mg/Fe] DR16 data. Along with predicted composition SSPs born at different Galactic times vicinity, we provide their maximum height |zmax| above plane computed assuming...
ABSTRACT Current stellar model predictions of adiabatic oscillation frequencies differ significantly from the corresponding observed due to non-adiabatic and poorly understood near-surface layers stars. However, certain combinations – known as frequency ratios are largely unaffected by uncertain physical processes they mostly sensitive core. Furthermore, seismic signature helium ionization provides envelope properties while being almost independent outermost layers. We have developed an...
We present the first data release of Kepler Smear Campaign, using collateral "smear" obtained in four-year mission to reconstruct light curves 102 stars too bright have been otherwise targeted. describe pipeline developed extract and calibrate these show that we attain photometric precision comparable analyzed by standard nominal mission. In this paper, aside from publishing stars, focus on 66 red giants for which detect solar-like oscillations, characterizing 33 detail with spectroscopic...