Title: Transit signatures of inhomogeneous clouds on hot Jupiters: Insights from microphysical cloud modellingAuthors: Diana Powell, Tom Louden, Laura Kreidberg, Xi Zhang, Peter Gao, Vivien ParmentierFirst Author’s Institution: University of California, Santa Cruz, California, USAStatus: Published in The Astrophysical Journal [closed access]
A crash course on transmission spectroscopy
Much of our knowledge about the atmospheric properties of exoplanets comes from transmission spectroscopy. An exoplanet’s apparent size (inferred from the amount of starlight it blocks out) varies with wavelength as molecules (plus atoms, ions, clouds or hazes) in the upper layer of the exoplanet’s atmosphere absorb different wavelengths of the star’s light. Clouds are especially important, as they affect atmospheric spectra and inhibit our ability to learn about the fundamental atmospheric properties for the majority of exoplanets (one example of this is shown in Figure 1). Not only are atmospheric clouds ubiquitous in our solar system, but many exoplanets show strong evidence for clouds (for example, GJ 1214b and HD 209458b)!
Figure 1: a) Clouds block the transmission of starlight, producing a flat transmission spectrum with dampened/weakened features. b) A clear atmosphere (with no clouds) allows starlight to penetrate deeper into the atmosphere, where molecules such as water absorb light. ...