# An Extreme Amplitude, Massive Heartbeat System in the LMC Characterized Using ASAS-SN and TESS

## TL;DR

This paper reports the discovery and analysis of the most extreme heartbeat star in the LMC, characterized by significant brightness variations due to tidal interactions, using ASAS-SN and TESS data.

## Contribution

It presents the identification and detailed characterization of an extreme amplitude heartbeat star in the LMC, including orbital and pulsation parameters, using combined photometric data.

## Key findings

- Extreme brightness variations of ~40% at periastron
- Orbital period of approximately 32.84 days
- Detection of tidally excited oscillations

## Abstract

Using ASAS-SN data, we find that the bright ($V{\sim}13.5$ mag) variable star MACHO 80.7443.1718 (ASASSN-V J052624.38-684705.6) is the most extreme heartbeat star yet discovered. This massive binary, consisting of at least one early B-type star, has an orbital period of $P_{\rm ASAS-SN}=32.83627\pm0.00846\,{\rm d},$ and is located towards the LH58 OB complex in the LMC. Both the ASAS-SN and TESS light curves show extreme brightness variations of ${\sim}40\%$ at periastron and variations of ${\sim}10\%$ due to tidally excited oscillations outside periastron. We fit an analytical model of the variability caused by the tidal distortions at pericenter to find orbital parameters of $\omega=-61.4$ deg, $i=44.8$ deg and $e=0.566$. We also present a frequency analysis to identify the pulsation frequencies corresponding to the tidally excited oscillations.