On the possible relation between Am stars and Brown Dwarfs

SAFFE, C; CALVO, DANIELA; ALACORIA, J.

San Juan

Congreso; 65 Reunión de la Asociación Argentina de Astronomía; 2023

Metallic-lined A stars (Am stars) are often components of short-period binary systems, where tidal interactions would result in low rotational velocities and help to develop the chemical peculiarities observed. However, the origin of single Am stars and Am stars that belong to wide binary systems is unclear. We studied a sample of 19 early-type stars, seven of them hosting hot BDs and 12 of them hosting hot Jupiter planets. We found that the incidence of Am stars hosting hot BDs is higher than thefrequency of Am stars in general (different to the case of Am stars hosting hot Jupiter planets). This would imply that the presence of hot BDs could play a role in the development of Am stars and possibly help to mitigate the single Am problem (Saffe+2022).