August 7-10, 2017

Abstract

Surprising activity of A-type stars revealed by Kepler: are magnetic fields the culprit?

James Sikora (Queen's University)

Gregg Wade (Royal Canadian Military College of Canada), Jason Rowe (Université of Montréal)

A recent analysis of photometry obtained using Kepler has revealed the highly unexpected result that 40% of main sequence A-type stars exhibit periodic variability that may be attributable to starspots. This is surprising in light of the fact that such activity is normally associated with the presence of magnetic fields, which are rare amongst stars much more massive than the Sun. Furthermore, a significant number of the Kepler A-type stars exhibit unusual signals in their periodograms, which have been attributed to a high frequency of hot Jupiters orbiting these stars. We will summarize these recent and currently unexplained discoveries and discuss (1) our ongoing efforts to understand their origins; and (2) whether or not this phenomena may also be found in BRITE photometry of main sequence A-type stars.

Mode of presentation need to be confirmed by the SOC