The impact of ultraviolet heating and cooling on the dynamics and observability of lava planet atmospheres

Abstract

Lava planets have non-global, condensible atmospheres similar to icy bodies within the solar system. Because they depend on interior dynamics, studying the atmospheres of lava planets can lead to understanding unique geological processes driven by their extreme environment. Models of lava planet atmospheres have thus far focused on either radiative transfer or hydrodynamics. In this study, we couple the two processes by introducing ultraviolet and infrared radiation to a turbulent boundary layer model. We also test the effect of different vertical temperature profiles on atmospheric dynamics. Results from the model show that UV radiation affects the atmosphere much more than IR. UV heating and cooling work together to produce a horizontally isothermal atmosphere away from the sub-stellar point regardless of the vertical temperature profile. We also find that stronger temperature inversions induce stronger winds and hence cool the atmosphere. Our simulated transmission spectra of the bound atmosphere show a strong SiO feature in the UV that would be challenging to observe in the planet’s transit spectrum due to the precision required. Our simulated emission spectra are more promising, with significant SiO spectral features at 4.5 and 9 μm that can be observed with the James Webb Space Telescope. Different vertical temperature profiles produce discernible dayside emission spectra, but not in the way one would expect.

K2 and Spitzer phase curves of the rocky ultra-short-period planet K2-141 b hint at a tenuous rock vapor atmosphere

“…Section 3 discusses the different models which were fit to the K2 and Spitzer data to extract information on the reflective and thermal emission coming from the planet. Section 4 compares the observations to two different atmospheric models: a pseudo-2D rock vapor model and a 1D turbulent boundary layer model, the latter being recently published in Nguyen et al (2020) and further improved in Nguyen et al (2022). In Sect.…”

“…Recent progress in these types of model have been made by including radiative transfer, in a three-band scheme (UV, optical and IR), for an SiO-dominated atmosphere (Nguyen et al 2022). SiO absorbs strongly in the UV, which causes upper-level atmospheric heating, possibly leading to a temperature inversion (Ito et al 2015).…”

“…This research has made use of the NASA/IPAC Infrared Science Archive, which is funded by the National Aeronautics and Space Administration and operated by the California Institute of Technology. We gratefully acknowledge the packages and tools that made this work possible: numpy (Harris et al 2020), matplotlib (Hunter 2007), scipy (Virtanen et al 2020), astropy (Astropy Collaboration 2013, 2018), ipython A79, page 13 of 30 A&A 664, A79 (2022) (Perez & Granger 2007), batman (Kreidberg 2015), SPIDERMAN (Louden & Kreidberg 2018), POET (Cubillos et al 2013), corner (Foreman-Mackey 2016), dynesty (Speagle 2020), MAGMA (Fegley & Cameron 1987;Schaefer & Fegley 2004), FastChem (Stock et al 2018), HELIOS (Malik et al 2017(Malik et al , 2019, petitRADTRANS (Mollière et al 2019). Finally, we thank the anonymous referee for a detailed report, which helped us to improve the quality of this paper.…”

Deep Two-phase, Hemispherical Magma Oceans on Lava Planets

“…Transits, eclipses, and phase variations of lava planets have been observed with the CoRoT, Kepler, and Spitzer space telescopes (Léger et al 2009;Batalha et al 2011;Demory et al 2016;Zieba et al 2022), and further observations have been approved for the Hubble and James Webb space telescopes (e.g., Dang et al 2021;Espinoza et al 2021;Hu et al 2021;Quinn et al 2021). These measurements constrain the surface temperature of a lava planet as a function of longitude, the atmospheric composition, and even the atmospheric temperature structure (Nguyen et al 2020;Zilinskas et al 2020;Zilinskas et al 2021;Nguyen et al 2022). While remote sensing can only directly probe an exoplanet's atmosphere and surface, one may sometimes indirectly infer properties of its interior (Cowan 2014).…”

“…We expect strong winds from the dayside to the nightside. Studies of lava planet atmospheres have focused on Na, because of its relative volatility (Castan & Menou 2011;Kite et al 2016;Nguyen et al 2020), or SiO, because of its abundance in the mantle (Nguyen et al 2020(Nguyen et al , 2022Zieba et al 2022). In either case, the atmosphere is expected to flow toward the day-night terminator at velocities of kilometers per second, often exceeding the speed of sound.…”