CFHT UM2025 - Presentation Details
Abstract Details
Title: Magnetic field, rotation, and binarity of the first magnetic B[e] star, IRAS 17449 2320.
Presenter: Iris Bermejo Lozano
Abstract:
IRAS17449 2320 is the first B[e] star with a detected magnetic field. It belongs to a subgroup of peculiar hot B-type stars, called FS CMa stars. These stars are surrounded by a huge amount of gas and dust, whose origin is still unclear. The most accepted scenario is binarity. However, a new scenario - the post-merger - was introduced as a consequence of the detection of the Zeeman splitting in some metal lines, e.g. C I, Fe I, in the spectrum of this star. Theoretical models suggest that magnetic fields are created during the merging process and can remain stable on evolutionary timescales. In this presentation, we describe recent work to confirm and characterize the magnetic field of IRAS17449 2320, and to refine its physical properties. After analyzing spectropolarimetric observations obtained with ESPaDOnS at the Canada-France-Hawaii Telescope, we have confirmed the detection and variability of the star’s magnetic field, and determined its rotational period. We have determined the stellar parameters through synthetic spectra modeling and modeled the magnetic field and its geometry with the Oblique Rotator Model. FS CMa stars could be an overlooked channel of intermediate mass post-merger objects. Understanding IRAS 17449 2320 and identifying more magnetic objects among this group is of special interest, as it may lead to better understanding of the merging process.