Enhancing The Detection Of Low-energy M Dwarf Flares: Wavelet-based Denoising Of CHEOPS Data
Stellar flares are powerful bursts of electromagnetic radiation triggered by magnetic reconnection in the chromosphere of stars, occurring frequently and intensely on active M dwarfs.
While missions like TESS and Kepler have studied regular and super-flares, their detection of flares with energies below 1030 erg remains incomplete. Extending flare studies to include these low-energy events could enhance flare formation models and provide insight into their impacts on exoplanetary atmospheres.
This study investigates CHEOPS’s capacity to detect low-energy flares in M dwarf light curves. Using CHEOPS’s high photometric precision and observing cadence, along with a tailored wavelet-based denoising algorithm, we aim to improve detection completeness and refine flare statistics for low-energy events.
We conducted a flare injection and recovery process to optimise denoising parameters, applied it to CHEOPS light curves to maximise detection rates, and used a flare breakdown algorithm to analyse complex structures.
Our analysis recovered 349 flares with energies ranging from 2.2×1026 to 8.1×1030 erg across 63 M dwarfs, with ∼40% exhibiting complex, multi-peaked structures. The denoising algorithm improved flare recovery by ∼34%, though it marginally extended the lower boundary of detectable energies.
For the full sample, the power-law index α was 1.92±0.07, but a log-normal distribution fit better, suggesting multiple flare formation scenarios. While CHEOPS’s observing mode is not ideal for large-scale surveys, it captures weaker flares than TESS or Kepler, expanding the observed energy range.
Wavelet-based denoising enhances low-energy event recovery, enabling exploration of the micro-flaring regime. Expanding low-energy flare observations could refine flare generation models and improve the understanding of their role in star-planet interactions.
J. Poyatos, O. Fors, J.M. Gómez Cama, I. Ribas
Comments: 29 pages, 20 figures, 4 tables, submitted to Astronomy & Astrophysics
Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM)
Cite as: arXiv:2412.15297 [astro-ph.SR] (or arXiv:2412.15297v1 [astro-ph.SR] for this version)
https://doi.org/10.48550/arXiv.2412.15297
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Submission history
From: Julien Poyatos
[v1] Thu, 19 Dec 2024 10:37:22 UTC (2,242 KB)
https://arxiv.org/abs/2412.15297
Astrobiology, Space Weather,
