A Search for High Frequency Oscillations in TESS Cycle 7

TL;DR

This study systematically searches TESS Cycle 7 data for high-frequency stellar oscillations, identifying 73 rapid oscillators across various stellar types and providing detailed frequency analyses to aid future asteroseismic research.

Contribution

It presents the first homogeneous, large-scale search for high-frequency oscillators in TESS Cycle 7, expanding the catalog of known rapid pulsators with detailed frequency measurements.

Findings

Identified 73 rapid oscillators including white dwarfs, subdwarfs, and A-F stars.

Detected frequency multiplets in some objects indicating rotational splitting.

Provided a uniform frequency-amplitude catalog for future asteroseismic studies.

Abstract

High-quality, short-cadence photometry from TESS enables the detection of rapid oscillators with unprecedented sensitivity. In this work, we conduct a homogeneous search for high-frequency variability using 20-second cadence light curves from TESS Cycle 7 (Sectors 84--96). From $\sim 3.9\times10^{4}$ light curves, we compute Lomb-Scargle periodograms and select candidates exhibiting at least one significant signal with $\mathrm{FAP}\le 10^{-4}$ at frequencies $f\ge 50~\mathrm{d^{-1}}$. After excluding previously reported objects and performing pixel-level and light-curve vetting to mitigate contamination, we identify 73 rapid oscillators, including 24 pulsating white dwarfs, 31 hot subdwarfs, and 18 A-F stars. Using an iterative prewhitening procedure, we carry out a detailed frequency analysis for each target and derive the oscillation frequencies and amplitudes. We further investigate the physical origins of the detected frequency content and present statistical characterizations of the rapid-oscillator sample. We highlight one white dwarf and one subdwarf that exhibit clear frequency multiplets consistent with rotational splitting. This work enlarges the sample of rapid oscillators accessible with TESS data and provides a uniformly measured frequency-amplitude catalog, establishing a consistent basis for future asteroseismic and population studies.