Binarity and Magnetic Interactions in various classes of Stars (BinaMIcS)
PIs:Evelyne Alecian, LESIA - Observatoire de Paris,
Gregg A. Wade, Royal Military College of Canada, Kingston,
Science
Magnetic fields are a crucial ingredient in a star’s evolution, influencing its formation, the structure of its
atmosphere and interior, as well as controlling the interaction with its environment. For binary stars magnetism is
even more significant, as magnetic fields in binary systems will be strongly affected by, and may also strongly
affect, the transfer of energy, mass and angular momentum between the components in these important stellar
systems. However, the interplay between stellar magnetic fields and binarity has yet to be investigated in any
real detail, from either an observational or theoretical point-of-view. Nevertheless, the incidence and
characteristics of magnetic fields are key parameters for understanding the physics of binaries. In higher-mass
stars (above 1.5 Solar masses) the incidence of magnetic stars in binary systems provides a basic constraint on the
detailed origin of the magnetic field, assumed to be fossil remnant, and whether such strong magnetic fields
suppress binary formation. In low-mass stars, tidal interactions are expected to induce large-scale 3D shear
and/or helical flows in stellar interiors that can significantly perturb the stellar dynamo. Similar flows may also
influence the fossil magnetic fields of higher-mass stars. Magnetically driven winds/outflows in cool and hot close
binary systems have long been suspected to be responsible for their orbital evolution, while magnetospheric
interactions have been proposed to enhance stellar activity. However, the crucial observational constraints
required to test these hypotheses are, at present, nearly nonexistent. The BinaMIcS project represents an
innovative large program with ESPaDOnS to study the complex phenomenon of stellar magnetism under
the influence of the unique physical processes and interactions occurring in close binary systems. Using
cutting-edge observations, sophisticated theory and realistic simulations, we will observe and model the
magnetic fields and the magnetospheric structure and coupling, of both components of hot and cool close binary
systems over a significant range of evolutionary stages. Our results will confront current theories and trigger new
ones, with the aim of qualitatively improving our understanding of the complex interplay between stellar
magnetism and binarity.
Observations
The Binarity and Magnetic Interactions in various classes of Stars is a CFHT large program that was allocated 604 hours of observing time on ESPaDOnS. The program was executed during the 2013A to 2016B semesters.
The data can be downloaded directly from the CADC using the following URLs:
Access all BinaMIcS data at the CADC.
Raw data only.
Processed data only.