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

Wide-field high precision photometric surveys such as Kepler have producedreams of data suitable for investigating stellar magnetic activity of coolerstars. Starspot activity produces quasi-sinusoidal light curves whose phase andamplitude vary as active regions grow and decay over time. Here we investigate,firstly, whether there is a correlation between the size of starspots - assumedto be related to the amplitude of the sinusoid - and their decay timescale and,secondly, whether any such correlation depends on the stellar effectivetemperature. To determine this, we computed the autocorrelation functions ofthe light curves of samples of stars from Kepler and fitted them with apodisedperiodic functions. The light curve amplitudes, representing spot size weremeasured from the root-mean-squared scatter of the normalised light curves. Weused a Monte Carlo Markov Chain to measure the periods and decay timescales ofthe light curves. The results show a correlation between the decay time ofstarspots and their inferred size. The decay time also depends strongly on thetemperature of the star. Cooler stars have spots that last much longer, inparticular for stars with longer rotational periods. This is consistent withcurrent theories of diffusive mechanisms causing starspot decay. We also findthat the Sun is not unusually quiet for its spectral type - stars withsolar-type rotation periods and temperatures tend to have (comparatively)smaller starspots than stars with mid-G or later spectral types.

A Kepler Study of Starspot Lifetimes with Respect to Light Curve Amplitude and Spectral Type