Revising the Rotational Period of NGC 1624-2

ORAL

Abstract

It has been found that approximately one in ten massive stars unexpectedly have large-scale surface magnetic fields. Considerable research effort has been aimed at understanding the origins of these fields, their characteristics, and their overall impact on massive star astrophysics. Among this subpopulation, NGC 1642-2 hosts the strongest magnetic field ever measured on an O-star (20 kG polar), which is ten times stronger than that of the 2nd in rank. We measure a new rotational period for NGC 1642-2 after finding that the previously adopted 157.99 ± 0.94 d period does not accurately phase-fold recent observations. We assemble a multi-epoch, multi-instrument, collection of spectroscopic and spectropolarimetric observations and analyze the variations of several optical spectral lines with Lomb Scargle and Phase Dispersion Minimization periodograms. We report a rotational period of 153.57 days, and report on the implications of this revised period for previous observational studies of this important star.

*This work has been done with National Science Foundation support under the grant NSF AST-2108455.

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Publication: Seadrow et al. (2022; in-prep)

Presenters

  • Shaquann S Seadrow

    • University of Delaware

Authors

  • Shaquann S Seadrow

    • University of Delaware

  • Véronique Petit

    • Dept. Of Physics and Astronomy, Bartol Research Institute, University of Delaware
    • University of Delaware, USA

  • Gregg Wade

    • Dept. of Physics, Royal Military College of Canada

  • Alexandre David-Uraz

    • University of Delaware, USA/Howard University, USA/NASA GSFC, USA
    • University of Delaware, USA; Howard University, USA; NASA/GSFC, USA

  • David Bohlender

    • Canadian Astronomy Data Centre

  • Jesús Maíz Apellániz

    • Astrophysics Department, Centro de Astrobiología, CSIC-INTA