Discovery of 17 new sharp-lined Ap stars with magnetically resolved lines★
Corresponding Author
L. M. Freyhammer
Centre for Astrophysics, University of Central Lancashire, Preston PR1 2HE
E-mail: [email protected]Search for more papers by this authorV. G. Elkin
Centre for Astrophysics, University of Central Lancashire, Preston PR1 2HE
Search for more papers by this authorD. W. Kurtz
Centre for Astrophysics, University of Central Lancashire, Preston PR1 2HE
Search for more papers by this authorG. Mathys
European Southern Observatory, Casilla 19001, Santiago 19, Chile
Search for more papers by this authorP. Martinez
South African Astronomical Observatory (SAAO), PO Box 9, Observatory 7935, South Africa
Search for more papers by this authorCorresponding Author
L. M. Freyhammer
Centre for Astrophysics, University of Central Lancashire, Preston PR1 2HE
E-mail: [email protected]Search for more papers by this authorV. G. Elkin
Centre for Astrophysics, University of Central Lancashire, Preston PR1 2HE
Search for more papers by this authorD. W. Kurtz
Centre for Astrophysics, University of Central Lancashire, Preston PR1 2HE
Search for more papers by this authorG. Mathys
European Southern Observatory, Casilla 19001, Santiago 19, Chile
Search for more papers by this authorP. Martinez
South African Astronomical Observatory (SAAO), PO Box 9, Observatory 7935, South Africa
Search for more papers by this authorBased on observations collected at the European Southern Observatory, Paranal, Chile, as part of programmes 078.D-0080(A), 078.D-0192(A), 072.D-0138(A).
ABSTRACT
Chemically peculiar A stars (Ap) are extreme examples of the interaction of atomic element diffusion processes with magnetic fields in stellar atmospheres. The rapidly oscillating Ap stars provide a means for studying these processes in three dimensions and are at the same time important for studying the pulsation excitation mechanism in A stars. As part of the first comprehensive, uniform, high-resolution spectroscopic survey of Ap stars, which we are conducting in the Southern hemisphere with the Michigan Spectral Catalogues as the basis of target selection, we report here the discovery of 17 new magnetic Ap stars having spectroscopically resolved Zeeman components from which we derive magnetic field moduli in the range 3–30 kG. Among these are (1) the current second strongest known magnetic A star, (2) a double-lined Ap binary with a magnetic component and (3) an A star with particularly peculiar and variable abundances. Polarimetry of these stars is needed to constrain their field geometries and to determine their rotation periods. We have also obtained an additional measurement of the magnetic field of the Ap star HD 92499.
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