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

HD 208472 is among the most active RS~CVn binaries with cool starspots.Decade-long photometry has shown that the spots seem to change theirlongitudinal appearance with a period of about six years, coherent withbrightness variations. Our aim is to spatially resolve the stellar surface ofHD 208472 and relate the photometric results to the true longitudinal andlatitudinal spot appearance. Furthermore, we investigate the surfacedifferential rotation pattern of the star. We employed three years ofhigh-resolution spectroscopic data with a high signal-to-noise ratio (S/N) fromthe STELLA robotic observatory and determined new and more precise stellarphysical parameters. Precalculated synthetic spectra were fit to each of thesespectra, and we provide new spot-corrected orbital elements. A sample of 34absorption lines per spectrum was used to calculate mean line profiles with aS/N of several hundred. A total of 13 temperature Doppler images werereconstructed from these line profiles with the inversion code iMap.Differential rotation was investigated by cross-correlating successive Dopplerimages in each observing season. Spots on HD 208472 are distributed preferablyat high latitudes and less frequently around mid-to-low latitudes. No polar-caplike structure is seen at any epoch. We observed a flip-flop event between 2009and 2010, manifested as a flip of the spot activity from phase 0.0 to phase0.5, while the overall brightness of the star continued to increase and reachedan all-time maximum in 2014. Cross-correlation of successive Doppler imagessuggests a solar-like differential rotation that is ~15 times weaker than thatof the Sun.

Time-series Doppler imaging of the red giant HD 208472. Active longitudes and differential rotation