G. Clementini
A5032071390- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- Gamma-ray bursts and supernovae
- Astro and Planetary Science
- Galaxies: Formation, Evolution, Phenomena
- History and Developments in Astronomy
- Scientific Research and Discoveries
- Geophysics and Gravity Measurements
- Adaptive optics and wavefront sensing
- Geomagnetism and Paleomagnetism Studies
- Astronomical and nuclear sciences
- Geological and Geophysical Studies
- Cosmology and Gravitation Theories
- Solar and Space Plasma Dynamics
- Earth Systems and Cosmic Evolution
- Astrophysical Phenomena and Observations
- Spacecraft and Cryogenic Technologies
- Calibration and Measurement Techniques
- Distributed and Parallel Computing Systems
- SAS software applications and methods
- Methane Hydrates and Related Phenomena
- BIM and Construction Integration
- Historical and Architectural Studies
Osservatorio di Astrofisica e Scienza dello Spazio
2018-2024
Istituto di Astrofisica Spaziale e Fisica Cosmica di Bologna
2018-2024
ARC Centre of Excellence for All-sky Astrophysics
2023
ASTRO-3D
2023
University of Bologna
2012-2022
National Institute for Astrophysics
2007-2022
Osservatorio astronomico di Bologna
2009-2018
Max Planck Society
2018
UK Astronomy Technology Centre
2012-2014
ETH Zurich
2014
Context. We present the second Gaia data release, DR2, consisting of astrometry, photometry, radial velocities, and information on astrophysical parameters variability, for sources brighter than magnitude 21. In addition epoch astrometry photometry are provided a modest sample minor planets in solar system. Aims. A summary contents DR2 is presented, accompanied by discussion differences with respect to DR1 an overview main limitations which still survey. Recommendations made responsible use...
Gaia is a cornerstone mission in the science programme of EuropeanSpace Agency (ESA). The spacecraft construction was approved 2006, following study which original interferometric concept changed to direct-imaging approach. Both and payload were built by European industry. involvement scientific community focusses on data processing for international Data Processing Analysis Consortium (DPAC) selected 2007. launched 19 December 2013 arrived at its operating point, second Lagrange point...
At about 1000 days after the launch of Gaia we present first data release, DR1, consisting astrometry and photometry for over 1 billion sources brighter than magnitude 20.7. We summarize DR1 provide illustrations scientific quality data, followed by a discussion limitations due to preliminary nature this release. consists of: primary astrometric set which contains positions, parallaxes, mean proper motions 2 million brightest stars in common with Hipparcos Tycho-2 catalogues secondary...
We present the third data release of European Space Agency's Gaia mission, GDR3. The GDR3 catalogue is outcome processing raw collected with instruments during first 34 months mission by Data Processing and Analysis Consortium. contains same source list, celestial positions, proper motions, parallaxes, broad band photometry in G, G$_{BP}$, G$_{RP}$ pass-bands already Early Third Release. introduces an impressive wealth new products. More than 33 million objects ranges $G_{rvs} < 14$ $3100...
Context. Gaia Data Release 2 provides high-precision astrometry and three-band photometry for about 1.3 billion sources over the full sky. The precision, accuracy, homogeneity of both are unprecedented. Aims. We highlight power DR2 in studying many fine structures Hertzsprung-Russell diagram (HRD). allows us to present different HRDs, depending particular on stellar population selections. do not aim here completeness terms types stars or evolutionary aspects. Instead, we have chosen several...
The goal of this paper is to demonstrate the outstanding quality second data release Gaia mission and its power for constraining many different aspects dynamics satellites Milky Way. We focus here on determining proper motions 75 Galactic globular clusters, nine dwarf spheroidal galaxies, one ultra-faint system, Large Small Magellanic Clouds. Using extracted from archive, we derived parallaxes these systems, as well their uncertainties. that errors, statistical systematic, are relatively...
High dispersion spectra () for a quite large number of stars at the main sequence turn-off and base giant branch in NGC 6397 6752 were obtained with UVES on Kueyen (VLT UT2). The [Fe/H] values we found are respectively, where first error bars refer to internal second ones systematic errors (within abundance scale defined by our analysis 25 subdwarfs good Hipparcos parallaxes). In both clusters [Fe/H]'s TO-stars agree perfectly few percent) that RGB. value obtain is low, but it agrees...
To illustrate the potential of GDR2, we provide a first look at kinematics Milky Way disc, within radius several kiloparsecs around Sun. We benefit for time from sample 6.4 million F-G-K stars with full 6D phase-space coordinates, precise parallaxes, and Galactic cylindrical velocities . From this sample, extracted sub-sample 3.2 giant to map velocity field disc $\sim$5~kpc $\sim$13~kpc centre up 2~kpc above below plane. also study distribution 0.3 solar neighbourhood ($r < 200$~pc), median...
We present the early installment of third Gaia data release, EDR3, consisting astrometry and photometry for 1.8 billion sources brighter than magnitude 21, complemented with list radial velocities from DR2. EDR3 contains celestial positions apparent brightness in G approximately sources. For 1.5 those sources, parallaxes, proper motions, (G_BP-G_RP) colour are also available. The passbands G, G_BP, G_RP provided as part release. ease use, 7 million DR2 included this after removal a small...
The Gaia second Data Release (DR2) presents a first mapping of full-sky RR Lyrae stars and Cepheids observed by the spacecraft during initial 22 months science operations. Specific Object Study (SOS) pipeline, developed to validate fully characterise (SOS Cep&RRL) Gaia, has been presented in documentation papers accompanying Release. Here we describe how SOS pipeline was modified allow for processing multiband (G, G_BP G_RP) time series photometry all-sky candidate variables produce specific...
The Gaia DR3 Catalogue contains for the first time about eight hundred thousand solutions with either orbital elements or trend parameters astrometric, spectroscopic and eclipsing binaries, combinations of them. This paper aims to illustrate huge potential this large non-single star catalogue. Using together models a catalogue tens thousands stellar masses, lower limits, partly consistent flux ratios, has been built. Properties concerning completeness binary catalogues are discussed,...
With the most recent Gaia data release number of sources with complete 6D phase space information (position and velocity) has increased to well over 33 million stars, while stellar astrophysical parameters are provided for more than 470 sources, in addition identification 11 variable stars. Using variability classifications DR3, we select various populations explore identify non-axisymmetric features disc Milky Way both configuration velocity space. about 580 thousand identified as hot OB...
Context. Gaia has been in operations since 2014. The third data release expands from the early (EDR3) 2020 by providing 34 months of multi-epoch observations that allowed us to probe, characterise and classify systematically celestial variable phenomena. Aims. We present a summary variability processing analysis photometric spectroscopic time series 1.8 billion sources done for DR3. Methods. used statistical Machine Learning methods sources. Training sets were built global revision major...
Gaia DR3 contains 1.8 billion sources with G-band photometry, 1.5 of which BP and RP complemented by positions on the sky, parallax, proper motion. The median number field-of-view transits in three photometric bands is between 40 44 measurements per source covers 34 months data collection. We pursue a classification Galactic extra-galactic objects that are detected as variable across whole sky. Supervised machine learning (eXtreme Gradient Boosting Random Forest) was employed to generate...
Gravitational waves from black-hole merging events have revealed a population of extra-galactic BHs residing in short-period binaries with masses that are higher than expected based on most stellar evolution models - and also known stellar-origin black holes our Galaxy. It has been proposed those high-mass the remnants massive metal-poor stars. Gaia astrometry is to uncover many Galactic wide-binary systems containing dormant BHs, which may not detected before. The study this will provide...
New improved distances and absolute ages for the Galactic globular clusters NGC 6397, 6752, 47 Tuc are obtained using Main Sequence Fitting Method. We derived accurate estimates of reddening metal abundance these three a strictly differential procedure, where Johnson Strömgren colours UVES high resolution spectra turn-off stars early subgiants belonging to were compared similar data field subdwarfs with parallaxes measured by Hipparcos. The use free temperature indicator (the profile Hα)...
We review the results on distances and absolute ages of Galactic globular clusters (GCs) obtained after release Hipparcos catalog. Several methods aimed at definition Population II local distance scale are discussed, their compared, exploiting new for RR Lyraes in Large Magellanic Cloud (LMC). find that so-called short long scales may be reconciled whether or not a consistent reddening is adopted Cepheids Lyrae variables LMC. Emphasis given paper to discussion GCs derived using parallaxes...
We report here initial but strongly conclusive results for absolute ages of Galactic globular clusters (GGCs). This study is based on high-precision trigonometric parallaxes from the HIPPARCOS satellite coupled with accurate metal abundances ([Fe/H], [O/Fe], and [α/Fe]) high-resolution spectroscopy a sample about thirty subdwarfs. Systematic effects due to star selection (Lutz-Kelker corrections parallaxes) possible presence undetected binaries in bona fide single stars are examined,...
New photometry and spectroscopy for more than a hundred RR Lyrae stars in two fields located close to the bar of Large Magellanic Cloud (LMC) are used derive new accurate estimates average magnitude, local reddening, luminosity-metallicity relation, distance LMC. The apparent luminosity Lyraes with complete V B light curves is ⟨V(RR)⟩ = 19.412 ± 0.019 (σ 0.153), ⟨B(RR)⟩ 19.807 0.022 0.172) our field A (62 stars) 19.320 0.023 0.159), 19.680 0.024 0.163) (46 stars). clump same areas 0.108...
The new VISual and Infrared Telescope for Astronomy (VISTA) has started operations. Over its first five years it will be collecting data six public surveys, one of these is the near-infrared YJKsVISTA survey Magellanic Clouds system (VMC). This comprises LMC, SMC, Bridge connecting two galaxies fields in Stream. paper provides an overview VMC strategy presents science results. main goals are determination spatially resolved SFH 3D structure system. Therefore, designed to reach stars as faint...
We present a photometric analysis of the star clusters Lindsay 1, Kron 3, NGC 339, 416, 38, and 419 in Small Magellanic Cloud (SMC), observed with Hubble Space Telescope Advanced Camera for Surveys (ACS) F555W F814W filters. Our color-magnitude diagrams (CMDs) extend ∼3.5 mag deeper than main-sequence turnoff points, any previous data. Cluster ages were derived using three different isochrone models: Padova, Teramo, Dartmouth, which are all available ACS system. Fitting ridgelines each...
The Gaia Data Release 2 contains the 1st release of radial velocities complementing kinematic data a sample about 7 million relatively bright, late-type stars. Aims: This paper provides detailed description spectroscopic processing pipeline, and approach adopted to derive presented in DR2. Methods: pipeline must perform four main tasks: (i) clean reduce spectra observed with Radial Velocity Spectrometer (RVS); (ii) calibrate RVS instrument, including wavelength, straylight, line-spread...
We present an overview of the Carnegie-Chicago Hubble Program, ongoing program to obtain a 3 per cent measurement constant using alternative methods traditional Cepheid distance scale. aim establish completely independent route RR Lyrae variables, tip red giant branch (TRGB), and Type Ia supernovae (SNe Ia). This ladder can be applied galaxies any Type, inclination, and, utilizing old stars in low density environments, is robust degenerate effects metallicity interstellar extinction. Given...