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

We performed an analysis of the main theoretical uncertainties that affectthe radius of low- and very-low mass-stars predicted by current stellar models.We focused on stars in the mass range 0.1-1Msun, on both the zero-agemain-sequence (ZAMS) and on 1, 2 and 5 Gyr isochrones. First, we quantified theimpact on the radius of the uncertainty of several quantities, namely theequation of state, radiative opacity, atmospheric models, convection efficiencyand initial chemical composition. Then, we computed the cumulative radius errorstripe obtained by adding the radius variation due to all the analysedquantities. As a general trend, the radius uncertainty increases with thestellar mass. For ZAMS structures the cumulative error stripe of very-low massstars is about $\pm 2$ and $\pm 3$ percent, while at larger masses it increasesup to $\pm 4$ and $\pm 5$ percent. The radius uncertainty gets larger and agedependent if isochrones are considered, reaching for $M\sim 1$Msun about$+12(-15)$ percent at an age of 5 Gyr. We also investigated the radiusuncertainty at a fixed luminosity. In this case, the cumulative error stripe isthe same for both ZAMS and isochrone models and it ranges from about $\pm 4$percent to $+7$ and $+9$($-5$) percent. We also showed that the soleuncertainty on the chemical composition plays an important role in determiningthe radius error stripe, producing a radius variation that ranges between about$\pm 1$ and $\pm 2$ percent on ZAMS models with fixed mass and about $\pm 3$and $\pm 5$ percent at a fixed luminosity.

Theoretical uncertainties on the radius of low- and very-low mass stars