English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Several studies have documented periodic and quasi-periodic signals from thetime series of dMe flare stars and other stellar sources. Such periodicsignals, observed within quiescent phases (i.e., devoid of larger-scalemicroflare or flare activity), range in period from $1-1000$ seconds and hencehave been tentatively linked to ubiquitous $p$-mode oscillations generated inthe convective layers of the star. As such, most interpretations for theobserved periodicities have been framed in terms of magneto-hydrodynamic wavebehavior. However, we propose that a series of continuous nanoflares, basedupon a power-law distribution, can provide a similar periodic signal in theassociated time series. Adapting previous statistical analyses of solarnanoflare signals, we find the first statistical evidence for stellar nanoflaresignals embedded within the noise envelope of M-type stellar lightcurves.Employing data collected by the Next Generation Transit Survey (NGTS), we findevidence for stellar nanoflare activity demonstrating a flaring power-law indexof $3.25 \pm 0.20 $, alongside a decay timescale of $200 \pm 100$ s. We alsofind that synthetic time series, consistent with the observations of dMe flarestar lightcurves, are capable of producing quasi-periodic signals in the samefrequency range as $p$-mode signals, despite being purely comprised ofimpulsive signatures. Phenomena traditionally considered a consequence of wavebehaviour may be described by a number of high frequency but discrete nanoflareenergy events. This new physical interpretation presents a novel diagnosticcapability, by linking observed periodic signals to given nanoflare modelconditions.

Statistical Signatures of Nanoflare Activity. II. A Nanoflare Explanation for Periodic Brightenings in Flare Stars observed by NGTS