TIC 5724661: A Long-Period Binary with a Pulsating sdB Star and $delta$ Scuti Variable. (arXiv:2111.12098v2 [astro-ph.SR] UPDATED)
<a href="http://arxiv.org/find/astro-ph/1/au:+Jayaraman_R/0/1/0/all/0/1">Rahul Jayaraman</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rappaport_S/0/1/0/all/0/1">Saul Rappaport</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nelson_L/0/1/0/all/0/1">Lorne Nelson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kurtz_D/0/1/0/all/0/1">Donald W. Kurtz</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dufresne_G/0/1/0/all/0/1">George Dufresne</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Handler_G/0/1/0/all/0/1">Gerald Handler</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Senhadji_A/0/1/0/all/0/1">Abdel Senhadji</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Latham_D/0/1/0/all/0/1">David W. Latham</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zhou_G/0/1/0/all/0/1">George Zhou</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bieryla_A/0/1/0/all/0/1">Allyson Bieryla</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ricker_G/0/1/0/all/0/1">George Ricker</a>
Using TESS 20-sec cadence data, we have discovered an unusual combination of
pulsating stars in what we infer to be a binary system. The binary consists of
a standard $delta$ Scuti star with pulsations over the range 32-41 d$^{-1}$;
this is in a likely wide orbit with a hot subdwarf B (sdB) star, which itself
has a large-amplitude p-mode pulsation at 524 d$^{-1}$. We establish
constraints on the period of the putative binary by using radial velocity
measurements of the $delta$~Scuti star and show that any sdB companion star
must orbit with a period greater than a few tens of days. Our identification of
this sdB binary serves as an important addition to the relatively small number
of sdB binaries known to have orbital periods longer than a few days. We model
such a binary using {tt MESA} and find that this system could be formed
through stable, nonconservative mass transfer from either a low- or
intermediate-mass progenitor, without undergoing a common envelope phase.
Using TESS 20-sec cadence data, we have discovered an unusual combination of
pulsating stars in what we infer to be a binary system. The binary consists of
a standard $delta$ Scuti star with pulsations over the range 32-41 d$^{-1}$;
this is in a likely wide orbit with a hot subdwarf B (sdB) star, which itself
has a large-amplitude p-mode pulsation at 524 d$^{-1}$. We establish
constraints on the period of the putative binary by using radial velocity
measurements of the $delta$~Scuti star and show that any sdB companion star
must orbit with a period greater than a few tens of days. Our identification of
this sdB binary serves as an important addition to the relatively small number
of sdB binaries known to have orbital periods longer than a few days. We model
such a binary using {tt MESA} and find that this system could be formed
through stable, nonconservative mass transfer from either a low- or
intermediate-mass progenitor, without undergoing a common envelope phase.
http://arxiv.org/icons/sfx.gif
