Binary and multiple magnetic Ap/Bp stars. Proceedings of IAUS 302: Magnetic fields throughout stellar evolution

TL;DR

This study used speckle interferometry at a 6-m telescope to resolve binary and multiple magnetic Ap/Bp stars, revealing new companions and estimating the binary fraction among magnetic stars.

Contribution

It provides the first resolution of many magnetic stars into binary or multiple systems and estimates the binary fraction, including spectroscopic and wide pairs.

Findings

Resolved 58 binary and 5 triple stars, many for the first time.

Estimated that about 23% of magnetic stars are in binary/multiple systems.

The distribution of separations peaks at close pairs.

Abstract

We present the results of speckle interferometric observations of 273 magnetic stars most of which are Ap/Bp type. All observations were made at the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences. We resolved 58 binary and 5 triple stars into individual components. Almost half of these stars were astrometrically resolved for the first time. The fraction of speckle interferometric binaries/multiples in the sample of stars with confirmed magnetic fields is 23%. We expect that the total fraction of binaries/multiples in the sample with account for spectroscopic short-period systems and wide common proper motion pairs can be twice higher. The detected speckle components have a prominent peak in the {\rho} distribution that corresponds to the closest resolved pairs.