AC Her: Evidence of the First Polar Circumbinary Planet
AC Her: Evidence of the First Polar Circumbinary Planet
Abstract We examine the geometry of the post–asymptotic giant branch (AGB) star binary AC Her and its circumbinary disk. We show that the observations describe a binary orbit that is perpendicular to the disk with an angular momentum vector that is within 9° of the binary eccentricity vector, meaning that …