Space Weather & Heliophysics

Analyzing the Morphology of Late-phase Stellar Flares From G-, K-, and M-type Stars

By Keith Cowing
Status Report
astro-ph.SR
March 24, 2025
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Analyzing the Morphology of Late-phase Stellar Flares From G-, K-, and M-type Stars
An active region on the sun emitted a mid-level solar flare, peaking at 4:47 a.m. EST on Nov. 5, 2014. This is the second mid-level flare from the same active region, labeled AR 12205, which rotated over the left limb of the sun on Nov. 3. — NASA

Stellar flares occasionally present a peak-bump light curve morphology, consisting of an initial impulsive phase followed by a gradual late phase. Analyzing this specific morphology can uncover the underlying physics of stellar flare dynamics, particularly the plasma heating-evaporation-condensation process.

While previous studies have mainly examined peak-bump occurrences on M-dwarfs, this report extends the investigation to G-, K-, and M-type stars. We utilize the flare catalog published by arXiv:2212.00993, encompassing 12,597 flares, detected by using Transiting Exoplanet Survey Satellite (TESS) observations.

Our analysis identifies 10,142 flares with discernible classical and complex morphology, of which 197 (∼1.9%) exhibit the peak-bump feature. We delve into the statistical properties of these TESS late-phase flares, noting that both the amplitude and full-width-half-maximum (FWHM) duration of both the peaks and bumps show positive correlations across all source-star spectral types, following a power law with indices 0.69 ± 0.09 and 1.0 ± 0.15, respectively.

Additionally, a negative correlation between flare amplitude and the effective temperature of their host stars is observed. Compared to the other flares in our sample, peak-bump flares tend to have larger and longer initial peak amplitudes and FWHM durations, and possess energies ranging from 1031 to 1036 erg.

Denise G. Yudovich, Kai E. Yang, Xudong Sun

Comments: 39 pages, 15 figures, 5 tables. this http URL and this http URL uploaded files provide machine-readable tables/data for tables 2 and 3, respectively
Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
Cite as: arXiv:2503.16181 [astro-ph.SR] (or arXiv:2503.16181v1 [astro-ph.SR] for this version)
https://doi.org/10.48550/arXiv.2503.16181
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Submission history
From: Denise Yudovich
[v1] Thu, 20 Mar 2025 14:24:37 UTC (1,716 KB)
https://arxiv.org/abs/2503.16181
Astrobiology, Space Weather, Heliophysics,

Keith Cowing

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻

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