TWO TOOLS FOR ESTIMATING STAR CLUSTER PARAMETERS

A star cluster is a composition of stars held together by the overall gravitational field of the whole cluster. The stars of a given cluster are born in a giant molecular cloud and, as such, can be regarded as objects with almost equal ages. Furthermore, assuming that the initial material in the cloud is perfectly mixed, we may also say that the metallicity of all cluster members is the same. Four parameters (distance, extinction or reddening, age, and metallicity) are standardly used to describe star clusters. Their knowledge is essential for studying galaxies’ local and global properties (especially our own Galaxy). However, deriving these parameters may take time and effort. Thanks to the Gaia mission’s parallax measurements, we can determine the distances of stars (and clusters) within our Galaxy with unprecedented precision. Therefore, we can remove the distance from the list of free parameters. We developed two different tools for estimating cluster parameters: 1) Metalcode, an automatic tool focused on deriving metallicities of open clusters, and 2) Stellar Isochrone Fitting Tool (StIFT), a tool for fitting a grid of isochrones for any photometric system available. We present both tools in more detail.

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