# A Search for Red Giant Solar-like Oscillations in All Kepler Data

## TL;DR

This study conducts the largest search for solar-like oscillations in red giants using all Kepler long-cadence data, identifying over 21,900 oscillating stars and providing detailed stellar parameter estimates.

## Contribution

It introduces a comprehensive method to detect red giant oscillations across all Kepler long-cadence data, significantly expanding the known sample of such stars.

## Key findings

- Detected oscillations in 21,914 stars, the largest sample to date.
- Achieved $
u_{ ext{max}}$ measurements down to 4 μHz with high precision.
- Found over 600 new red giants, many likely belonging to the galactic halo.

## Abstract

The recently published Kepler mission Data Release 25 (DR25) reported on ~197,000 targets observed during the mission. Despite this, no wide search for red giants showing solar-like oscillations have been made across all stars observed in Kepler's long-cadence mode. In this work, we perform this task using custom apertures on the Kepler pixel files and detect oscillations in 21,914 stars, representing the largest sample of solar-like oscillating stars to date. We measure their frequency at maximum power, $\nu_{\mathrm{max}}$, down to $\nu_{\mathrm{max}}\simeq4\mu$Hz and obtain $\log(g)$ estimates with a typical uncertainty below 0.05 dex, which is superior to typical measurements from spectroscopy. Additionally, the $\nu_{\mathrm{max}}$ distribution of our detections show good agreement with results from a simulated model of the Milky Way, with a ratio of observed to predicted stars of 0.992 for stars with 10$\mu$Hz $ <\nu_{\mathrm{max}}<270\mu$Hz. Among our red giant detections, we find 909 to be dwarf/subgiant stars whose flux signal is polluted by a neighbouring giant as a result of using larger photometric apertures than those used by the NASA Kepler Science Processing Pipeline. We further find that only 293 of the polluting giants are known Kepler targets. The remainder comprises over 600 newly identified oscillating red giants, with many expected to belong to the galactic halo, serendipitously falling within the Kepler pixel files of targeted stars.