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. Many efforts are being made to characterize extrasolar planetarysystems and unveil the fundamental mechanisms of planet formation. An importantaspect of the problem, which remains largely unknown, is to understand how theplanet formation process depends on the mass of the parent star. In particular,as most planets discovered to date orbit a solar-mass primary, little is knownabout planet formation around more massive stars. Aims. To investigate thispoint, we present first results from a radial velocity planet search around redgiants in the clump of intermediate-age open clusters. We choose clustersharbouring red giants with masses between 1.5 and 4 M_sun, using the well-knowncluster parameters to accurately determine the stellar masses. We are thereforeexploring a poorly-known domain of primary masses, which will bring newinsights into the properties of extrasolar planetary systems. Methods. We arefollowing a sample of about 115 red giants with the Coralie and HARPSspectrographs to obtain high-precision radial velocity (RV) measurements anddetect giant planets around these stars. We use bisector and activity indexdiagnostics to distinguish between planetary-induced RV variations and stellarphotospheric jitter. Results. We present the discoveries of a giant planet anda brown dwarf in the open clusters NGC 2423 and NGC 4349, orbiting the 2.4M_sun-star NGC2423 No3 (TYC 5409-2156-1) and the 3.9 M_sun-star NGC4349 No127(TYC 8975-2606-1). These low-mass companions have orbital periods of 714 and678 days and minimum masses of 10.6 and 19.8 M_jup, respectively. Combined withthe other known planetary systems, these detections indicate that the frequencyof massive planets is higher around intermediate-mass stars, and thereforeprobably scales with the mass of the protoplanetary disk.

Planets around evolved intermediate-mass stars. I. Two substellar companions in the open clusters NGC 2423 and NGC 4349