BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Mineral cloud and hydrocarbon haze particles for the JWST target W
 ASP-43b - Christiane Helling (St Andrews)
DTSTART:20210216T130000Z
DTEND:20210216T140000Z
UID:TALK155881@talks.cam.ac.uk
CONTACT:Paul B. Rimmer
DESCRIPTION:WASP-43b is an extrasolar\, giant gas planet that has been sel
 ected as a JWST target because it orbits a near-solar abundance K7V star a
 t a distance of a ≈ 0.0153 au in 0.813 days. Its atmosphere can therefor
 e be well characterised through transmission spectroscopy and thermal emis
 sion measurements. Applying a combined modelling approach of 3D GCMs\, kin
 etic cloud and photochemically driven hydrocarbon haze formation\, we prov
 ide insight into the details of the clouds that may form on WASP-43b\, and
  their impact on the remaining gas phase.\n\nMineral condensation seeds fo
 rm throughout the atmosphere of WASP-43b. This is in stark contrast to the
  ultra-hot Jupiters\, like WASP-18b and HAT-P-7b. The dayside is not cloud
  free but is loaded with few but large mineral cloud particles in addition
  to hydrocarbon haze particles of comparable abundance. Photochemically dr
 iven hydrocarbon haze appears on the dayside\, but does not contribute to 
 the cloud formation on the nightside. The geometrical cloud extension diff
 ers across the globe due to the changing thermodynamic conditions. Day and
  night differ by 6000km in pressure scale height. As reported for other pl
 anets\, the C/O is not constant throughout the atmosphere and varies betwe
 en 0.74 and 0.3. The mean molecular weight is approximately constant in a 
 H2-dominated WASP-43b atmosphere because of the moderate day/night-tempera
 ture differences compared to the super-hot Jupiters. \n\nWe therefore expe
 ct that WASP-43b is expected to be fully covered in clouds which are not h
 omogeneously distributed throughout the atmosphere. The dayside and the te
 rminator clouds will be a combination of mineral particles of locally vary
 ing size and composition\, and of hydrocarbon hazes. The optical depth of 
 hydrocarbon hazes is considerably lower than that of mineral cloud particl
 es such that a wavelength-dependent radius measurement of WASP-43b would b
 e determined by the mineral cloud particles but not by hazes.
LOCATION:ONLINE - Details to be sent by email
END:VEVENT
END:VCALENDAR