Binarity and Stellar Evolution

A–type stars: evolution, rotation and binarity

We discuss the internal structure of stars in the mass range 1.5 to 4M⊙ from the PMS to the subgiant phase with a particular emphasis on the convective core and the convective superficial layers. Different physical aspects are considered such as overshooting, treatment of convection, microscopic diffusion and rotation. Their influence on the internal structure and on the photospheric chemical a...

Stellar Structure and Evolution

Photometric biases due to stellar blending: implications for measuring distances, constraining binarity and detecting exoplanetary transits

We investigate blending, binarity and photometric biases in crowded-field CCD imaging. For this, we consider random blend losses, which correspond to the total number of stars left undetected in unresolved blends. We present a simple formula to estimate blend losses, which can be converted to apparent magnitude biases using the luminosity function of the analyzed sample. Because of the used ass...

Lithium and binarity

We present an analysis of the lithium abundances in late spectral type binaries of different ages. They belong to several open clusters (Pleiades, Hyades and M67), as well as to Chromospherically Active Binary Systems (CABS). All these binaries have reliable ages, since they are members of wellknown open clusters or, in the case of the CABS, some stellar parameters such masses and radii are acc...

FUors and Early Stellar Evolution

Ambartsumian was among the first researchers who recognized the importance and uniqueness of FUors, the term he coined for the rare outburst sources of the FU Orionis type. A wealth of observational data and concomitant theoretical work has advanced our understanding of FUors in the intervening almost 40 years. These results are summarized in this brief review, with special emphasis on observat...