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Much progress has been achieved in the age-dating of old stellar systems, and even of individual stars in the field, in the more than sixty years since the evolution of low-mass stars was first correctly described. In this paper, I provide an overview of some of the main methods that have been used in this context, and discuss some of the issues that still affect the determination of accurate ages for the oldest stars.
This article aims to measure the age of planet-hosting stars (SWP) through stellar tracks and isochrones computed with the textsl{PA}dova & Ttextsl{R}ieste textsl{S}tellar textsl{E}volutionary textsl{C}ode (PARSEC). We developed algorithms based on t
We use the ages of old astrophysical objects (OAO) in the redshift range $0 lesssim z lesssim 8$ as stringent tests of the late-time cosmic expansion history. Since the age of the Universe at any redshift is inversely proportional to $H_0$, requiring
Understanding the origin of the elements has been a decades long pursuit, with many open questions still remaining. Old stars found in the Milky Way and its dwarf satellite galaxies can provide answers because they preserve clean elemental patterns o
The age distribution of the central stars of planetary nebulae (CSPN) is estimated using two methods based on their kinematic properties. First, the expected rotation velocities of the nebulae at their Galactocentric distances are compared with the p
We report time-series photometry for 55 variable stars located in the central part of the globular cluster M55. The sample includes 28 newly identified objects of which 13 are eclipsing binaries. Three of these are detached systems located in the tur