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

Determining fundamental properties of stars through stellar modeling hasimproved substantially due to recent advances in asteroseismology. Thanks tothe unprecedented data quality obtained by space missions, particularly CoRoTand Kepler, invaluable information is extracted from the high-precision stellaroscillation frequencies, which provide very strong constraints on possiblestellar models for a given set of classical observations. In this work, we havecharacterized two relatively faint stars, KIC10920273 and KIC11395018, usingoscillation data from Kepler photometry and atmospheric constraints fromground-based spectroscopy. Both stars have very similar atmospheric properties;however, using the individual frequencies extracted from the Kepler data, wehave determined quite distinct global properties, with increased precisioncompared to that of earlier results. We found that both stars have left themain sequence and characterized them as follows: KIC10920273 is aone-solar-mass star (M=1.00 +/- 0.04 M_sun), but much older than our Sun(t=7.12 +/- 0.47 Gyr), while KIC11395018 is significantly more massive than theSun (M=1.27 +/- 0.04 M_sun) with an age close to that of the Sun (t=4.57 +/-0.23 Gyr). We confirm that the high lithium abundance reported for these starsshould not be considered to represent young ages, as we precisely determinedthem to be evolved subgiants. We discuss the use of surface lithium abundance,rotation and activity relations as potential age diagnostics.

Characterizing two solar-type Kepler subgiants with asteroseismology: KIC10920273 and KIC11395018