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

(shortened for arXiv) We aim to progress towards more efficient exoplanetdetection around active stars by optimizing the use of Doppler Imaging inradial velocity measurements. We propose a simple method to simultaneouslyextract a brightness map and a set of orbital parameters through a tomographicinversion technique derived from classical Doppler mapping. Based on themaximum entropy principle, the underlying idea is to determine the set oforbital parameters that minimizes the information content of the resultingDoppler map. We carry out a set of numerical simulations to perform apreliminary assessment of the robustness of our method, using an actual Dopplermap of the very active star HR 1099 to produce a realistic synthetic data setfor various sets of orbital parameters of a single planet in a circular orbit.Using a simulated time-series of 50 line profiles affected by a peak-to-peakactivity jitter of 2.5 km/s, we are able in most cases to recover the radialvelocity amplitude, orbital phase and orbital period of an artificial planetdown to a radial velocity semi-amplitude of the order of the radial velocityscatter due to the photon noise alone (about 50 m/s in our case). Onenoticeable exception occurs when the planetary orbit is close to co-rotation,in which case significant biases are observed in the reconstructed radialvelocity amplitude, while the orbital period and phase remain robustlyrecovered. The present method constitutes a very simple way to extract orbitalparameters from heavily distorted line profiles of active stars, when moreclassical radial velocity detection methods generally fail. It is easilyadaptable to most existing Doppler Imaging codes, paving the way towards asystematic search for close-in planets orbiting young, rapidly-rotating stars.

A maximum entropy approach to detect close-in giant planets around active stars