English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

KIC 8569819 is an eclipsing binary star with an early F primary and Gsecondary in a 20.85-d eccentric orbit. The primary is a delta Sct - gamma Dorstar pulsating in both p modes and g modes. Using 4 years of Kepler Missionphotometric data we independently model the light curve using the traditionaltechnique with the modelling code PHOEBE, and we study the orbitalcharacteristics using the new frequency modulation (FM) technique. We show thatboth methods provide the equivalent orbital period, eccentricity and argumentof periastron, thus illustrating and validating the FM technique. In theamplitude spectrum of the p-mode pulsations we also discovered an FM signalcompatible with a third body in the system, a low mass M dwarf in an 861-dorbit around the primary pair. However, the eclipses show no timing variations,indicating that the FM signal is a consequence of the intrinsic change inpulsation frequency, thus providing a cautionary tale. Our analysis shows thepotential of the FM technique using {\it Kepler} data, and we discuss theprospects to detect planets and brown dwarfs in Kepler data for A and F starseven in the absence of transits and with no spectroscopic radial velocitycurves. This opens the possibility of finding planets orbiting hotter starsthat cannot be found by traditional techniques.

Validation of the Frequency Modulation technique applied to the pulsating delta Sct - gamma Dor eclipsing binary star KIC 8569819