The Complex Circumstellar and Circumbinary Environment of V356 Sgr

Authors

Jamie R. Lomax, University of Oklahoma, University of Washington
Andrew G. Fullard, University of Denver
Michael A. Malatesta, University of Oklahoma
Brian Babler, University of Wisconsin-Madison
Daniel Bednarski, Universidade de São Paulo
Jodi R. Berdis, University of Oklahoma
Karen S. Bjorkman, University of Toledo
Jon E. Bjorkman, University of Toledo
Alex C. Carciofi, Universidade de São Paulo
James W. Davidson, University of Virginia
Marcus Keil, University of Oklahoma
Marilyn R. Meade, University of Wisconsin-Madison
Kenneth Nordsieck, University of Wisconsin-Madison
Matt Scheffler, University of Oklahoma
Jennifer L. Hoffman, University of Denver
John P. Wisniewski, University of Oklahoma

Publication Date

9-20-2016

Document Type

Article

Organizational Units

College of Natual Science and Mathematics, Physics and Astronomy

Keywords

Polarization, Binaries, Eclipsing, Circumstellar matter, Stars, Massive stars, Individual, V356 Sgr

Abstract

We analyse 45 spectropolarimetric observations of the eclipsing, interacting binary star V356 Sgr, obtained over a period of ∼21 yr, to characterize the geometry of the system's circumstellar material. After removing interstellar polarization from these data, we find that the system exhibits a large intrinsic polarization signature arising from electron scattering. In addition, the lack of repeatable eclipses in the polarization phase curves indicates the presence of a substantial pool of scatterers not occulted by either star. We suggest that these scatterers form either a circumbinary disc coplanar with the gainer's accretion disc or an elongated structure perpendicular to the orbital plane of V356 Sgr, possibly formed by bipolar outflows. We also observe small-scale, cycle-to-cycle variations in the magnitude of intrinsic polarization at individual phases, which we interpret as evidence of variability in the amount of scattering material present within and around the system. This may indicate a mass-transfer or mass-loss rate that varies on the time-scale of the system's orbital period. Finally, we compare the basic polarimetric properties of V356 Sgr with those of the well-studied β Lyr system; the significant differences observed between the two systems suggest diversity in the basic circumstellar geometry of Roche lobe overflow systems.

Publication Statement

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Recommended Citation

Lomax, Jamie R, Fullard, Andrew G, Malatesta, Michael A, Babler, Brian, Bednarski, Daniel, Berdis, Jodi R, Bjorkman, Karen S, Bjorkman, Jon E, Carciofi, Alex C, Davidson, James W, Keil, Marcus, Meade, Marilyn R, Nordsieck, Kenneth, Scheffler, Matt, Hoffman, Jennifer L, and Wisniewski, John P. "The Complex Circumstellar and Circumbinary Environment of V356 Sgr." Monthly Notices of the Royal Astronomical Society 464.2 (2017): 1936-947. Web. doi: 10.1093/mnras/stw2457.