# Multi-epoch Low Radio Frequency Surveys of the Kepler K2 Mission Campaign Fields 3, 4, and 5 with the Murchison Widefield Array

## TL;DR

This study uses the Murchison Widefield Array to conduct low-frequency radio surveys of Kepler K2 fields, improving data processing and setting new upper limits on transient object densities, confirming the rarity of radio transients at these wavelengths.

## Contribution

It provides the first systematic low-frequency survey of Kepler K2 fields with improved data analysis, establishing more stringent upper limits on radio transient surface densities.

## Key findings

- No variable objects detected above 2e-4 per square degree at ~500 mJy.
- Survey achieved nearly an order of magnitude better upper limits than previous studies.
- Radio transients at meter and centimeter wavelengths remain rare.

## Abstract

We present Murchison Widefield Array (MWA) monitoring of the Kepler K2 mission Fields 3, 4, and 5 at frequencies of 155 and 186 MHz, from observations contemporaneous with the K2 observations. This work follows from previous MWA and GMRT surveys of Field 1, with the current work benefiting from a range of improvements in the data processing and analysis. We continue to build a body of systematic low frequency blind surveys overlapping with transient/variable survey fields at other wavelengths, providing multi-wavelength data for object classes such as flare stars. From the current work, we detect no variable objects at a surface density above 2e-4 per square degree, at flux densities of ~500 mJy, and observation cadence of days to weeks, representing almost an order of magnitude decrease in measured upper limits compared to previous results in this part of observational parameter space. This continues to show that radio transients at metre and centimetre wavelengths are rare.