Connecting the atmosphere and the interior in extrasolar gas planets

<p>We investigate how radiatively driven heating and cooling in the upper atmosphere (at pressures below 1 bar) influences the interior temperature profile (at pressures between 1 to 700 bar) by means of dynamical heat transport. To achieve this goal, we perform fully coupled 3D-radiation-hydrodymamical models with the new full RT 3D climate model MITgcm/ExoRadPRT for WASP-43 b and HD209458 b. We show in our simulations under which conditions the interior temperature profile converges to a hot deep adiabat. Furthermore, we show if differences occur between the non inflated WASP-43 b and the inflated HD209458 b due to different flow structures at depth for similar irradiation.</p>

Swift UVOT near-UV transit observations of WASP-121 b

Close-in gas planets are subject to continuous photoevaporation that can erode their volatile envelopes. Today, ongoing mass loss has been confirmed in a few individual systems via transit observations in the ultraviolet spectral range. We demonstrate that the Ultraviolet/Optical Telescope (UVOT) onboard the Neil Gehrels Swift Observatory enables photometry to a relative accuracy of about 0.5% and present the first near-UV (200–270 nm, NUV) transit observations of WASP-121 b, a hot Jupiter with one of the highest predicted mass-loss rates. The data cover the orbital phases 0.85–1.15 with three visits. We measure a broadband NUV transit depth of 2.10 ± 0.29%. While still consistent with the optical value of 1.55%, the NUV data indicate excess absorption of 0.55% at a 1.9σ level. Such excess absorption is known from the WASP-12 system, and both of these hot Jupiters are expected to undergo mass loss at extremely high rates. With a Cloudy simulation, we show that absorption lines of Fe II in a dense extended atmosphere can cause broadband near-UV absorption at the 0.5% level. Given the numerous lines of low-ionization metals, the NUV range is a promising tracer of photoevaporation in the hottest gas planets.

7. Rocks on other planets

Rocks are not just an Earthly phenomenon. They make up the surfaces of some of the planets of the solar system and, in one form or another, those all of the many moons, innumerable comets, and other small objects that orbit out to great distances from the Sun. They likely also lie deep beneath the immensely thick fluid envelopes of the gas giants. ‘Rocks on other planets’ describes what scientists have discovered about the rocks of Mercury, Venus, Mars, our moon, the giant gas planets, and distant moons and planets. The early exploration of exoplanets suggests that an even wider variety of rock formations likely exists on star systems other than ours.