Selection of metal-poor stars using narrow-band photometry

• Grant number: 25/03913-4
• Support Opportunities: Scholarships in Brazil - Master
• Start date: June 01, 2025
• End date: February 28, 2027
• Field of knowledge: Physical Sciences and Mathematics - Astronomy - Stellar Astrophysics
• Principal Investigator: Felipe de Almeida Fernandes
• Grantee: Tainá Bueno de Andrade
• Host Institution: Instituto Nacional de Pesquisas Espaciais (INPE). Ministério da Ciência, Tecnologia e Inovação (Brasil). São José dos Campos , SP, Brazil
• Associated research grant: 24/00822-5 - Narrow-band photometry applications for galactic archaeology, AP.JP

Abstract

Stars with the lowest metal abundances are direct descendants of the first stellar generation and serve as fossil records of the Universe's initial conditions. They provide valuable insights into the formation and evolution of the Milky Way and its satellite galaxies. This research aims to identify and characterize second-generation stars, formed from a primordial interstellar medium enriched by a single nucleosynthesis event. These stars are crucial for nucleosynthesis studies, as they enable direct comparisons between observations and theoretical models of different stellar processes.Only a few dozen of these stars are known. Using S-PLUS survey data, two new objects were discovered. The initial selection relied on a color-color diagram sensitive to metallicity, later refined through a chrono-chemo-dynamical analysis, which excluded stars from the Galactic thin and thick disks, as they are generally more metal-rich.Previous studies were limited to the third S-PLUS Data Release, covering about 1000 square degrees. With DR5 expanding this area to 4000 square degrees and an expected total of 9000 square degrees in the final years of S-PLUS, the project will refine and extend previous analyses. This larger and more precise photometric sample will enable the identification of more ultra- and extremely metal-poor stars, allowing for detailed follow-up studies.