Tag: GES

A first homogeneous study on the dynamics of stellar clusters. The paper: “The Gaia-ESO Survey: 3D dynamics of young groups and clusters from GES and Gaia EDR3” of N. J. Wright (Keele University) recently appeared on MNRAS

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Stars do not form in isolation. During gravitational collapse, molecular clouds fragment, forming a large number of stars. For this reason, young stars are typically observed as members of star clusters or associations.   In the past decade, the study of stellar clusters in the Milky Way has undergone a revolution, thanks to observations from the Gaia satellite of the

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Stellar lithium abundances may not be representative of the interstellar medium composition. The study: “The Gaia-ESO Survey: Probing the lithium abundances in old metal-rich dwarf stars in the solar vicinity” of M. L. L. Dantas (Nicolaus Copernicus Astronomical Center) appeared on A&A

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The study of chemical abundances in the interstellar medium and stars in our Galaxy is of utmost importance, as it provides insights into the chemical enrichment of the galactic interstellar medium by massive stars and the evolution of different components of the Milky Way. Lithium is frequently the subject of spectroscopic surveys and studies aimed at determining its abundance in

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A catalog of Lithium abundances from the Gaia-ESO Survey. The study: “The Gaia-ESO Survey: Lithium measurements and new curves of growth” of E.Franciosini (INAF-OA Arcetri) recently appeared on A&A

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In astrophysics, there are elements that provide important diagnostics used in various fields, such as Lithium. For instance, measurements of Lithium abundances are important in cosmology where there is a well-known problem of matching the measured abundances in population II stars with those predicted by cosmological models of Big Bang synthesis. Measurements of Lithium abundances are also essential for understanding

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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 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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Lithium abundance and stellar internal structure. The study: “The Gaia-ESO survey: Mixing processes in low-mass stars traced by lithium abundance in cluster and field stars” of L. Magrini (INAF – OA Arcetri) recently appeared on A&A

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The chemical history of Lithium abundance in the Universe is very complex. This chemical element has been first produced during the Big Bang, even if in very small quantities compared with hydrogen and helium. Since then, lithium is continuously created and destroyed by several processes occurring in stellar interior. This means that the lithium abundances we observe in stars today

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A comparison between different diagnostics of the age of stellar clusters. The study: “The Gaia-ESO survey: a lithium depletion boundary age for NGC 2232” of A. S. Binks (Keele University) recently appeared on MNRAS

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Measuring stellar ages is a difficult task but nevertheless very important. For instance, the study of stellar evolution requires accurate estimate of stellar ages. On the other hand, we can count on very few diagnostics that can allow astronomers to obtain reliable estimate of stellar ages, and typically these methods can be applied only to specific type of stars or

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Age and chemistry of the giant stars. The study: “The Gaia-ESO survey: Calibrating a relationship between age and the [C/N] abundance ratio with open clusters” of G. Casali (INAF – Osservatorio Astrofisico di Arcetri) recently appeared on A&A

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Despite its importance for our comprehension of stellar and galactic evolution, stellar age is one of the most elusive stellar properties. In fact, we are able to determine stellar age with a good precision only in a few cases. Typical methods to determine this quantity are: the study of the chemical abundance of Lithium, stellar kinematics, stellar pulsations analyzed by

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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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The chronology of star formation in the Lagoon.The study: “The Gaia-ESO Survey: Age spread in the star forming region NGC 6530 from the HR diagram and gravity indicators” of L. Prisinzano (INAF-OAPA) recently appeared on A&A

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Stars form from the gravitational contraction of large gas clouds. This process may occur in two different modes: It may be fast, with a characteristic timescale dictated by the free fall of gas onto the forming stars, or it may be slow, sustained by turbulence and magnetic field. In the former case stars form over a short period, while in

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