Tag: ammassi stellari

Chemistry and rotation of the B stars in the stellar cluster NGC3293. The study: “The Gaia-ESO survey: A spectroscopic study of the young open cluster NGC 3293” of T. Morel (Université de Liège) appeared on A&A

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Spectroscopic observations of massive stars (i.e., those more massive than 8 solar masses) allow astronomers to study their rapid evolution, which occurs on much shorter timescales compared to solar mass stars, and the impact of parameters such as stellar rotation on their evolution. To achieve this, observations of stellar clusters are greatly valuable, as they are groups of stars formed

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A new catalog of the Young Stellar Objects within 4500 light years based on Gaia/EDR3. The study: “Low mass young stars in the Milky Way unveiled by DBSCAN and Gaia EDR3. Mapping the star forming regions within 1.5 Kpc” of L. Prisinzano (INAF – OAPA) recently published by A&A

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After their formation, during the first few million of years (how many? it depends on the mass: the larger the stellar mass the faster is their evolution) stars continue to contract under their the action of their own gravity, rising their temperature and density. During this phase, their nuclei have not started yet the thermonuclear reactions that will power the

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A large catalog of stars associated with stellar clusters recently compiled in the framework of the Gaia-ESO Survey.

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Star clusters are a product of the star formation process. During their gravitational collapse, in fact, molecular clouds fragment forming hundreds or even thousands of stars. During the first few tens of million of years of their evolution, the young stars formed in a cloud are bound by the intense mutual gravitational attraction, forming a stellar cluster. Star clusters are important

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Dynamic and expansion of stellar clusters. The study: “The Gaia-ESO Survey: asymmetric expansion of the Lagoon Nebula cluster NGC 6530 from GES and Gaia DR2” of N. J. Wright (Keele University) recently appeared on MNRAS

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Despite a significant fraction of stars form in stellar clusters counting hundreds to thousands of members, almost all the stars we observe today in the Milky Way is not associated to any stellar cluster. This occurs because newborn stellar clusters are typically dispersed in a few million of years by several intervening processes, such as the gravitational interaction among cluster

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Two LSST white paper are led by INAF-OAPA astronomers

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LSST (Large Synoptic Survey Telescope) is the future of the astronomy in the time domain. LSST is a new-generation telescope that will be built on Cerro Pachon in Chile (2700 meters). It will be equipped with a primary mirror of 8.4 meters of diameter and an innovative camera able to observe an very large field of view, more than 49

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Star formation in the Vela. Published on A&A the study: “Low-mass star formation and subclustering in the H II regions RCW 32, 33, and 27 of the Vela Molecular Ridge. A photometric diagnostics for identifying M-type stars” of L. Prisinzano (INAF-OAPA)

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In the Milky Way one of the main modes of star formation is in stellar clusters, which remain associated with their parental cloud for about 5-10 million years. This makes the star forming regions complex targets, characterised by rich stellar populations packed into small regions, sometime even with massive stars, and clouds whose morphology and properties are affected by the

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Struttura ed evoluzione degli ammassi nell’associazione Vela OB2. Pubblicato su A&A: “The Gaia DR2 view of the Gamma Velorum cluster: resolving the 6D structure” di E. Franciosini (INAF-Arcetri)

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of Mario Giuseppe Guarcello    ( follow mguarce)   We are living a golden age for the research on stellar clusters and their structure, formation and evolution. This thanks to the satellite Gaia of the European Space Agency, which will provide position and radial velocity of over one billion stars with unprecedented precision, and the project Gaia-ESO Survey, an ambitious spectroscopic

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The Gaia-ESO survey and the evolution of stellar clusters. Published on A&A “The Gaia-ESO Survey: kinematical and dynamical study of four young open clusters” of L. Bravi (INAF-OA Arcetri)

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Despite the stars in our Galaxy typically formed in stellar clusters, only a small fraction of them today is observed associated with a cluster. This led to the conclusion that stellar clusters typically disperse in 10-100 million years. Two mechanisms are thought to be responsible for the dispersion of stellar clusters. According to the model of the “residual gas expulsion”,

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Published on A&A: “The Gaia-ESO Survey: radial distribution of abundances in the Galactic disc from open clusters and young-field stars” by L. Magrini

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Massive stars are enormous chemical laboratories where heavy chemical elements are synthesized. For instance, the alpha-elements (O, Mg, Si, Ca, and Ti) are produced by nucleosynthetic processes in the interior of massive stars. Moreover, the lifetime of massive stars is much shorter than that of low mass stars: few million years for the former compared to several billion of years

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