Discovery of {delta} Scuti Pulsations in the Young Hybrid Debris Disk Star HD 156623. (arXiv:1811.04118v1 [astro-ph.SR])

Discovery of {delta} Scuti Pulsations in the Young Hybrid Debris Disk Star HD 156623. (arXiv:1811.04118v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Mellon_S/0/1/0/all/0/1">Samuel N. Mellon</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mamajek_E/0/1/0/all/0/1">Eric E. Mamajek</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zwintz_K/0/1/0/all/0/1">Kostanze Zwintz</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+David_T/0/1/0/all/0/1">Trevor J. David</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Stuik_R/0/1/0/all/0/1">Remko Stuik</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Talens_G/0/1/0/all/0/1">Geert Jan J. Talens</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dorval_P/0/1/0/all/0/1">Patrick Dorval</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Burggraaff_O/0/1/0/all/0/1">Olivier Burggraaff</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kenworthy_M/0/1/0/all/0/1">Matthew A. Kenworthy</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bailey_J/0/1/0/all/0/1">John I. Bailey III</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lomberg_B/0/1/0/all/0/1">Blaine B. D. Lomberg</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kuhn_R/0/1/0/all/0/1">Rudi B. Kuhn</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ireland_M/0/1/0/all/0/1">Michael J. Ireland</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Crawford_S/0/1/0/all/0/1">Steven M. Crawford</a>

The bRing robotic observatory network was built to search for circumplanetary
material within the transiting Hill sphere of the exoplanet $beta$ Pic b
across its bright host star $beta$ Pic. During the bRing survey of $beta$
Pic, it simultaneously monitored the brightnesses of thousands of bright stars
in the southern sky ($V$ $simeq$ 4-8, $delta$ $lesssim$ -30$^{circ}$). In
this work, we announce the discovery of $delta$ Scuti pulsations in the A-type
star HD 156623 using bRing data. HD 156623 is notable as it is a well-studied
young star with a dusty and gas-rich debris disk, previously detected using
ALMA. We present the observational results on the pulsation periods and
amplitudes for HD 156623, discuss its evolutionary status, and provide further
constraints on its nature and age. We find strong evidence of frequency
regularity and grouping. We do not find evidence of frequency, amplitude, or
phase modulation for any of the frequencies over the course of the
observations. We show that HD 156623 is consistent with other hot and high
frequency pre-MS and early ZAMS $delta$ Scutis as predicted by theoretical
models and corresponding evolutionary tracks, although we observe that HD
156623 lies hotter than the theoretical blue edge of the classical instability
strip. This, coupled with our characterization and Sco-Cen membership analyses,
suggest that the star is most likely an outlying ZAMS member of the $sim$16
Myr Upper Centaurus-Lupus subgroup of the Sco-Cen association.

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