Open clusters and Galactic structure

• Grant number: 24/15923-1
• Support Opportunities: Research Grants - Visiting Researcher Grant - Brazil
• Start date: March 01, 2025
• End date: August 31, 2025
• Field of knowledge: Physical Sciences and Mathematics - Astronomy - Stellar Astrophysics
• Principal Investigator: Jacques Raymond Daniel Lépine
• Grantee: Jacques Raymond Daniel Lépine
• Visiting researcher: Wilton da Silva Dias
• Visiting researcher institution: Instituto De Física E Química/Ifq/Unifei, Brazil
• Host Institution: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Open clusters are widely used in studies of the structure of the Galaxy because they are distributed throughout the galactic plane, and because their distances and especially ages can be determined with good precision through isochrone fit.The publication of the Gaia DR2 and Gaia DR3 catalogues has made it possible to determine with greater precision the stars that belong to open clusters. However, it is possible to note that different methods continue to provide significant differences in the lists of members, implying discordant results for the parameters of the clusters obtained by different authors.The question of the rotation speed of the spiral arms and, therefore, the most appropriate explanation for the dynamics of the Galactic disk is currently under debate.In this context, this project describes how we intend to use the data from the Gaia DR3 and Gaia DR4 catalogs to build a homogeneous catalog of open clusters, performing member selection and isochrone fit, to be made available to the scientific community and mainly how to apply them to determine the rotation speed of the spiral arms and consequently the location of the Galaxy's co-rotation radius. (AU)