Short-period Heartbeat Binaries from TESS Full-Frame Images

TL;DR

This study identifies 240 short-period binary systems in TESS data, focusing on heartbeat binaries, analyzing their orbital parameters, and measuring relativistic and apsidal precession effects.

Contribution

First comprehensive analysis of short-period heartbeat binaries in TESS data, including orbital parameter estimation and precession rate measurements.

Findings

180 heartbeat binaries identified

Eccentricity cutoff at 1.7 days period

Prograde apsidal precession observed up to 9°/yr

Abstract

We identify $240$ short-period ($P \lesssim 10$ days) binary systems in the TESS data, $180$ of which are heartbeat binaries (HB). The sample is mostly a mix of A and B-type stars and primarily includes eclipsing systems, where over $30\%$ of the sources with primary and secondary eclipses show a secular change in their inter-eclipse timings and relative eclipse depths over a multi-year timescale, likely due to orbital precession. The orbital parameters of the population are estimated by fitting a heartbeat model to their phase curves and Gaia magnitudes, where the model accounts for ellipsoidal variability, Doppler beaming, reflection effects, and eclipses. We construct the sample's period-eccentricity distribution and find an eccentricity cutoff (where $e \rightarrow 0$) at a period $1.7$ days. Additionally, we measure the periastron advance rate for the $12$ of the precessing sources and find that they all exhibit prograde apsidal precession, which is as high as $9^{\circ}$ yr$^{-1}$ for one of the systems. Using the inferred stellar parameters, we estimate the general relativistic precession rate of the argument of periastron for the population and expect over $30$ systems to show a precession in excess of $0.3^{\circ}$ yr$^{-1}$