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 atmospheres of gaseous giant exoplanets orbiting close to their parentstars (hot Jupiters) have been probed for nearly two decades. They allow us toinvestigate the chemical and physical properties of planetary atmospheres underextreme irradiation conditions. Previous observations of hot Jupiters as theytransit in front of their host stars have revealed the frequent presence ofwater vapour and carbon monoxide in their atmospheres; this has been studied interms of scaled solar composition under the usual assumption of chemicalequilibrium. Both molecules as well as hydrogen cyanide were found in theatmosphere of HD 209458b, a well studied hot Jupiter (with equilibriumtemperature around 1,500 kelvin), whereas ammonia was tentatively detectedthere and subsequently refuted. Here we report observations of HD 209458b thatindicate the presence of water (H2O), carbon monoxide (CO), hydrogen cyanide(HCN), methane (CH4), ammonia (NH3) and acetylene (C2H2), with statisticalsignificance of 5.3 to 9.9 standard deviations per molecule. Atmospheric modelsin radiative and chemical equilibrium that account for the detected speciesindicate a carbon-rich chemistry with a carbon-to-oxygen ratio close to orgreater than 1, higher than the solar value (0.55). According to existingmodels relating the atmospheric chemistry to planet formation and migrationscenarios, this would suggest that HD 209458b formed far from its presentlocation and subsequently migrated inwards. Other hot Jupiters may also show aricher chemistry than has been previously found, which would bring intoquestion the frequently made assumption that they have solar-like andoxygen-rich compositions.

Five carbon- and nitrogen-bearing species in a hot giant planet's atmosphere