High-precision analysis of a benchmark binary system using MAROON-X spectra

PAULA MIQUELARENA; CARLOS SAFFE; FLORES MATÍAS; DANIELA CALVO; JHON YANA GALARZA

San Juan

Congreso; Reunión de la Asociación Argentina de Astronomía; 2023

Asociación Argentina de Astronomía

he chemical tagging technique is a powerful tool for identifying co-natal stars that have dispersed into the Galactic disc based on their chemical composition alone (e.g. Freeman & Bland-Hawthorn 2002; Casamiquela et al. 2021). Recent studies of open clusters have supported the assumption that members of a birth cluster should have a chemically homogeneous composition, showing coherence in metallicity up to 0.02-0.03 dex (e.g. Liu et al. 2016; Casamiquela et al. 2020, 2021). However, the internal coherence of chemical tagging was strongly challenged by the discovery of the comoving pair studied in this work, which has a mutual difference in iron content of around 0.20 dex - the highest difference found to date between two stars with a supposed common origin.Moreover, understanding the origin of the remarkable metallicity difference between this binary system is equally important. This requires studying the relative volatile-to-refractory content between both stars and condensation temperature (TC) trend. Previous studies suggest that the abundance differences correlate with condensation temperature and that this trend is a signature of planet formation (Meléndez et al. 2009). However, other explanations for the TC trend are possible (e.g. Meléndez et al. 2017, Booth & Owen 2020), and further research is needed to fully understand the origin of this metallicity difference.