NHFP Symposium | Slides at http://hyad.es/talks
Joel Ong, Marc Hon, Melinda Soares-Furtado, et al.
September 19, 2023
\(\ell = 0\) MDI Doppler velocities
Power spectra of MDI dopplergrams
\[ \begin{aligned} {\Delta\nu_\odot} &\sim 135\ \mathrm{\mu Hz} \\ {\nu_{\text{max},\odot}} &\sim 3090\ \mathrm{\mu Hz} \end{aligned} \]
(roughly 5-minute oscillations)
p-mode frequencies satisfy \(\nu_{n\ell} \sim \Delta\nu\left(n + {\ell \over 2} + \epsilon_\ell(\nu)\right) + \mathcal{O}(1/\nu)\)
Stochastic,
broad-band
excitation
\(\implies\) equipartition
between different \(m\)
Hare “Zebedee”, Cunha+ (incl. Ong, 2021)
Precise measurements of field stars: \[ {\sigma_R \over R} \lesssim 2 \%; {\sigma_M \over M} \lesssim 5 \% \]
Very high \(\mathrm{A(Li)}\),
but otherwise innocuous
\[\ell = 0,2?\]
But Kepler says \(\ell =
0\) have to live here!
(and theory says so too…)
Rotational splittings from seismology:
\(\implies P_\text{rot} \sim 115\ \mathrm{d}?\)
Rotational signal probably got
detrended away
by systematic corrections…
Very suggestive…
but is this real?
Probably yes!
Asteroseismology:
Photometry:
Spectroscopy:
Gaia DR3:
Gaia RV scatter rules out
large RV semiamplitudes…
\(P_\text{orb} \gg 99\ \mathrm{d}\)
cannot spin star
up to 99-day rotational period…
Remaining permissible orbits are
unstable to tidal dissipation!
\(\implies\) ENGULFMENT?
TESS finds a lithium-rich, rapidly rotating,
and likely standalone red giant, with rotation
confirmed independently using ASAS-SN, seismology,
\(V \sin i\).
Other constraints from spectroscopy and Gaia
strongly suggest an engulfment scenario.
If engulfment, \(< 5\ \mathrm{Mya}\), with mass about \(6\)-\(10\ M_J\).
\[\mathrm{j}\mathrm{o}\mathrm{e}\mathrm{l}\mathrm{o}\mathrm{n}\mathrm{g}\ \text{@}\ \text{hawaii}.\text{edu}\]
V501 Aur: a red giant accidentally misclassified as
a WTT!
(Vaňko et al. 2017: spectroscopic binary with \(K = 27\ \mathrm{km/s}, P \sim 69\
\mathrm{d}\))