AUTHOR=Balona Luis A. 

TITLE=The Hot Limit of Solar-like Oscillations From Kepler Photometry

JOURNAL=Frontiers in Astronomy and Space Sciences

VOLUME=7

YEAR=2020

URL=https://www.frontiersin.org/journals/astronomy-and-space-sciences/articles/10.3389/fspas.2020.529025

DOI=10.3389/fspas.2020.529025

ISSN=2296-987X

ABSTRACT=<p><italic>Kepler</italic> short-cadence photometry of 2,347 stars with effective temperatures in the range 6,000–10,000 K was used to search for the presence of solar-like oscillations. The aim is to establish the location of the hot end of the stochastic convective excitation mechanism and to what extent it may overlap the <italic>δ</italic> Scuti/<italic>γ</italic> Doradus instability region. A simple but effective autocorrelation method is described which is capable of detecting low-amplitude solar-like oscillations, but with significant risk of a false detection. The location of the frequency of maximum oscillation power, <inline-formula id="inf1"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>ν</mml:mi><mml:mrow><mml:mtext>max</mml:mtext></mml:mrow></mml:msub></mml:mrow></mml:math></inline-formula>, and the large frequency separation, <inline-formula id="inf2"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mtext>Δ</mml:mtext><mml:mi>ν</mml:mi></mml:mrow></mml:math></inline-formula>, is determined for 167 stars hotter than 6,000 K, of which 70 are new detections. Results indicate that the hot edge of excitation of solar-like oscillations does not appear to extend into the <italic>δ</italic> Scuti/<italic>γ</italic> Doradus instability strip.</p>