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

The processes regulating protoplanetary disk evolution are constrained bystudying how mass accretion rates scale with stellar and disk properties. Thespread in these relations can be used as a constraint to the models of diskevolution, but only if the impact of accretion variability is correctlyaccounted for. While the effect of variability might be substantial in theembedded phases of star formation, it is often considered limited at laterstages. Here we report on the observed large variation in the accretion ratefor one target, XX Cha, and we discuss the impact on population studies ofclassical T Tauri stars. The mass accretion rate determined by fitting theUV-to-near-infrared spectrum in recent X-Shooter observations is compared withthe one measured with the same instrument 11 years before. XX Cha displays anaccretion variability of almost 2 dex between 2010 and 2021. Although thetimescales on which this variability happens are uncertain, XX Cha displays anextreme accretion variability for a classical T Tauri star. If such behavior iscommon among classical T Tauri stars, possibly on longer timescales thanpreviously probed, it could be relevant for discussing the disk evolutionmodels constrained by the observed spread in accretion rates. Finally, weremark that previous studies of accretion variability based on spectral linesmay have underestimated the variability of some targets.

PENELLOPE III. The peculiar accretion variability of XX Cha and its impact on the observed spread of accretion rates