Tidally Excited Oscillations in Heartbeat Binary Stars: Pulsation Phases and Mode Identification. (arXiv:1911.08687v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Guo_Z/0/1/0/all/0/1">Zhao Guo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Shporer_A/0/1/0/all/0/1">Avi Shporer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hambleton_K/0/1/0/all/0/1">Kelly Hambleton</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Isaacson_H/0/1/0/all/0/1">Howard Isaacson</a>
Tidal forces in eccentric binary stars known as heartbeat stars excite
detectable oscillations that shed light on the processes of tidal
synchronization and circularization. We examine the pulsation phases of tidally
excited oscillations (TEOs) in heartbeat binary systems. The target list
includes four published heartbeat binaries and four additional systems observed
by {it Kepler}. To the first order, the pulsation phases of TEOs can be
explained by the geometric effect of the dominant $l=2$, $m=0$, or $pm 2$
modes assuming pulsations are adiabatic. We found that this simple theoretical
interpretation can account for more than half of the systems on the list,
assuming their spin and orbit axes are aligned. We do find significant
deviations from the adiabatic predictions for some other systems, especially
for the misaligned binary KIC 8164262. The deviations can potentially help to
probe the non-adiabaticity of pulsation modes as well as resonances in the
tidal forcing.
Tidal forces in eccentric binary stars known as heartbeat stars excite
detectable oscillations that shed light on the processes of tidal
synchronization and circularization. We examine the pulsation phases of tidally
excited oscillations (TEOs) in heartbeat binary systems. The target list
includes four published heartbeat binaries and four additional systems observed
by {it Kepler}. To the first order, the pulsation phases of TEOs can be
explained by the geometric effect of the dominant $l=2$, $m=0$, or $pm 2$
modes assuming pulsations are adiabatic. We found that this simple theoretical
interpretation can account for more than half of the systems on the list,
assuming their spin and orbit axes are aligned. We do find significant
deviations from the adiabatic predictions for some other systems, especially
for the misaligned binary KIC 8164262. The deviations can potentially help to
probe the non-adiabaticity of pulsation modes as well as resonances in the
tidal forcing.
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