|Support type:||Scholarships in Brazil - Post-Doctorate|
|Effective date (Start):||December 01, 2015|
|Effective date (End):||March 31, 2018|
|Field of knowledge:||Physical Sciences and Mathematics - Astronomy - Stellar Astrophysics|
|Principal researcher:||Marcos Perez Diaz|
|Grantee:||Patricia Cardoso Cruz|
|Home Institution:||Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brazil|
The characterization of low-mass binary stars, by the determination of their physical and orbital parameters, allows the study of the first stages of evolution of binary systems, and the formation of Cataclysmic Variables. The M-dwarf eclipsing binaries (MEBs) give the most precise ways to measure their fundamental properties, when photometric and spectroscopic data are combined. Nevertheless, only a few MEB systems were well characterized until now and the available data present considerable divergence when compared to stellar models. The radii of the M-dwarfs measured so far are from 5 to 10% greater than the expected values derived from spectral models. Such effect is known as the radius anomaly of low-mass stars. Recently, 16 new low-mass eclipsing binaries were discovered by the WFCAM Transit Survey (WTS), however, only three of them were fully characterized. Every new MEB found is significantly important, given that there are only a few systems known. Therefore, new spectroscopic data were already acquired with the objective to characterize five new MEBs discovered in the WTS. In addition to the determination of the physical and orbital parameters of these systems, an analysis of the relation between mass, radius and orbital period of these objects will be performed in order to investigate the mass-radius relationship by comparing the obtained radii of both components of each system studied with values derived from models of stellar evolution.