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Related papers: The W-function applied to the age of Globular Clus…

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We present an update of our on-going effort to improve the precision of white dwarf cosmochronology via careful analyses of white dwarf photometry in open clusters. To improve the precision of white dwarf and main sequence age analysis, we…

Astrophysics · Physics 2007-05-23 T. von Hippel , D. E. Winget , W. H. Jefferys , J. G. Scott

We present a method to build a probability density function (pdf) for the age of a star based on its peculiar velocities $U$, $V$ and $W$ and its orbital eccentricity. The sample used in this work comes from the Geneva-Copenhagen Survey…

Solar and Stellar Astrophysics · Physics 2018-01-31 Felipe Almeida-Fernandes , Helio Jaques Rocha-Pinto

The Gaia mission has provided highly accurate observations that have significantly reduced the scatter in the colour-magnitude diagrams of open clusters. As a result of the improved isochrone sequence of the open cluster M67, we have…

Solar and Stellar Astrophysics · Physics 2024-07-09 Claudia Reyes , Dennis Stello , Marc Hon , Regner Trampedach , Eric Sandquist , Marc Pinsonneault

We present Hubble Space Telescope ACS deep photometry of the intermediate-age globular cluster NGC 1783 in the Large Magellanic Cloud. By using this photometric dataset, we have determined the degree of ellipticity of the cluster…

Astrophysics · Physics 2009-06-23 A. Mucciarelli , L. Origlia , F. R. Ferraro

Context: Analysis of ages and metallicities of star clusters in the Magellanic Clouds provide information for studies on the chemical evolution of the Clouds and other dwarf irregular galaxies. Aims: The aim is to derive ages and…

Solar and Stellar Astrophysics · Physics 2015-03-13 Bruno Dias , Paula Coelho , Beatriz Barbuy , Leandro Kerber , Thais Idiart

Integrated spectra have been obtained of 31 star clusters in the Magellanic Clouds (MC) and of 4 Galactic globular clusters. The spectra cover the wavelength range 3500 -- 4700 Angstroms at a resolution of 3.2 Angstroms FWHM. The MC…

Astrophysics · Physics 2007-05-23 Andrew. J. Leonardi , James. A. Rose

In this paper we discuss the cluster and field star formation in the central part of the Small Magellanic Cloud. The main goal is to study the correlation between young objects and their interstellar environment. The ages of about 164…

Astrophysics · Physics 2009-11-11 E. Chiosi , A. Vallenari , E. V. Held , L. Rizzi , A. Moretti

We investigate how isochrones computed with different input physics and initial conditions affect the age dating of the open cluster NGC 6866, and compare the results with asteroseismic ages derived from Kepler photometry. Using Gaia DR3…

Solar and Stellar Astrophysics · Physics 2026-04-06 Haotian Wang , Gang Li , Dario J. Fritzewski , Timothy Van Reeth , Conny Aerts

We present preliminary results from our on-going survey of Galactic globular clusters relative ages. The investigation is based on V,I images obtained at the ESO and La Palma telescopes, which make up the largest homogenous photometric…

Astrophysics · Physics 2007-05-23 Ivo Saviane , Alfred Rosenberg , Giampaolo Piotto

An analysis of ages, metallicities, and [alpha/Fe] ratios of globular cluster systems in early-type galaxies is presented, based on Lick index measurements summarized in Puzia et al. (2004, Paper I of this series). In the light of…

A meta-analysis of seismic ages determined for individual stars in the well-studied open and globular clusters NGC 6819, NGC 6791, M67, M4, M19, M80, and M9 reveals both high variance across measurements and significant discrepancy with…

Solar and Stellar Astrophysics · Physics 2025-02-14 Jamie Tayar , Meridith Joyce

JWST observations of the strongly lensed galaxy The Sparkler have revealed a population of gravitationally bound globular cluster (GC) candidates. Different analyses have resulted in broadly similar ages but significantly different…

Astrophysics of Galaxies · Physics 2023-06-28 Angela Adamo , Christopher Usher , Joel Pfeffer , Adélaïde Claeyssens

We derive ages, metallicities and [alpha/Fe] ratios from the integrated spectra of 23 globular clusters in M31, by employing multivariate fits to two stellar population models. In parallel we analyze spectra of 21 Galactic globular clusters…

Globular clusters trace the formation history of the spheroidal components of both our Galaxy and others, which represent the bulk of star formation over the history of the universe. They also exhibit a range of metallicities, with…

The ages of the most common stars - low-mass (cool) stars like the Sun, and smaller - are difficult to derive because traditional dating methods use stellar properties that either change little as the stars age or are hard to measure. The…

Solar and Stellar Astrophysics · Physics 2015-06-23 Soren Meibom , Sydney A. Barnes , Imants Platais , Ronald L. Gilliland , David W. Latham , Robert D. Mathieu

We use evolutionary calculations presented in a recent paper (Cassisi et al. 1998) to predict B,V,I magnitudes for stars in galactic globulars. The effect of the adopted mixing length on stellar magnitudes and colors is discussed, showing…

Astrophysics · Physics 2009-10-31 S. Cassisi , V. Castellani , S. Degl'Innocenti , M. Salaris , A. Weiss

Many observable properties of globular clusters (GCs) provide valuable insights for unveiling the hierarchical assembly of their host galaxy. For the Milky Way (MW) in particular, GCs from different accreted satellite galaxies show distinct…

Astrophysics of Galaxies · Physics 2024-04-05 Yingtian Chen , Oleg Y. Gnedin

We present a new absolute age determination for NGC 6791, one of the Milky Way's oldest and most metal-rich open clusters. Its unusual properties make it an important probe of inner-disk evolution and asteroseismic calibration, but its age…

Solar and Stellar Astrophysics · Physics 2026-05-22 George Dufresne , Brian Chaboyer , Rayna Rampalli

We present a program designed to obtain age-rotation measurements of solar-type dwarfs to be used in the calibration of gyrochronology relations at ages of several Gyr. This is a region of parameter space crucial for the large-scale study…

Solar and Stellar Astrophysics · Physics 2015-05-30 Julio Chanamé , Iván Ramírez

Models of stellar structure and evolution can be constrained by measuring accurate parameters of detached eclipsing binaries in open clusters. Multiple binary stars provide the means to determine helium abundances in these old stellar…