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

Context. Variability caused by stellar activity represents a challenge to thediscovery and characterization of terrestrial exoplanets and complicates theinterpretation of atmospheric planetary signals.  Aims. We aim to use a detailed modeling tool to reproduce the effect ofactive regions on radial velocity measurements, which aids the identificationof the key parameters that have an impact on the induced variability.  Methods. We analyzed the effect of stellar activity on radial velocities as afunction of wavelength by simulating the impact of the properties of spots,shifts induced by convective motions, and rotation. We focused our modelingeffort on the active star YZ CMi (GJ 285), which was photometrically andspectroscopically monitored with CARMENES and the Telescopi Joan Or\'o.  Results. We demonstrate that radial velocity curves at different wavelengthsyield determinations of key properties of active regions, including spotfilling factor, temperature contrast, and location, thus solving the degeneracybetween them. Most notably, our model is also sensitive to convective motions.Results indicate a reduced convective shift for M dwarfs when compared tosolar-type stars (in agreement with theoretical extrapolations) and points to asmall global convective redshift instead of blueshift.  Conclusions. Using a novel approach based on simultaneous chromatic radialvelocities and light curves, we can set strong constraints on stellar activity,including an elusive parameter such as the net convective motion effect.

The CARMENES search for exoplanets around M dwarfs: Convective shift and starspot constraints from chromatic radial velocities