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 Tools annual

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 monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

We present a new method for determining the age of late-K type pre-mainsequence (PMS) stars by deriving their surface gravity from high-resolutionI-band spectroscopy. Since PMS stars contract as they evolve, age can beestimated from surface gravity. We used the equivalent width ratio (EWR) ofnearby absorption lines to create a surface gravity diagnostic of PMS starsthat is free of uncertainties due to veiling. The ratios of Fe (818.67nm and820.49nm) and Na (818.33nm and 819.48nm) absorption lines were calculated forgiants, main-sequence stars, and weak-line T Tauri stars. Effectivetemperatures were nearly equal across the sample. The Fe to Na EWR (Fe/Na)decreases significantly with increasing surface gravity, denoting that Fe/Na isa desirable diagnostic for deriving the surface gravity of pre-main sequencestars. The surface gravity of PMS stars with 0.8 solar mass is able to bedetermined with an accuracy of 0.1-0.2, which conducts the age of PMS starswithin a factor of 1.5, in average.

Age Determination Method of Pre-Main Sequence Stars with High-Resolution I-Band Spectroscopy