Early Stage of Chemically Peculiar Stars

NETOPIL, M.; FOSSATI, L.; ZWINTS, K.; PAUNZEN, E.; BAGNULO, S.; PINTADO, O. I.

Physics and Evolution of Magnetic and Related Stars, ASP Vol. 494

Astronomical Society of the Pacifics

Lugar: San Francisco; Año: 2015; p. 148 - 151

Chemically peculiar stars are known to be the main sequence objects andare characterized by a wide variety of element abundance patterns. Theydisplay abundance peculiarities of various chemical elements from heliumto mercury in their photospheres. These are explained by the diffusionprocesses driven by the competition between the radiative levitation andgravitational settling. Current estimates suggest that about 10% of allthe stars in the corresponding spectral range (B to F-type) belong tovarious CP groups. The most populous groups are the metallic line (Am)stars and the magnetic Bp/Ap objects. The reason and the time-scale forthe rise of chemical peculiarities is still not known, so is for therole of the magnetic field. The investigation of very young CP stars canhelp to shed more light on these issues and to test the diffusiontheory. However, so far only one pre-main sequence (PMS) Bp star isknown. We present here the discovery of a PMS CP candidate, which veryprobably belongs to the group of Am CP stars.