4 papers
A Hycean Interpretation of K2-18b Supported by Photochemical Atmospheric Compositional
Takuya Fujisawa, Masashi Shimada, Tatsuya Yoshida +1
The nature of the sub-Neptune K2-18b is debated between Hycean and mini-Neptune interpretations. We test whether self-consistent Hycean atmospheres are compatible with current JWST…
Water-Cooled (sub)-Neptunes Get Better Gas Mileage
Tatsuya Yoshida, Eric Gaidos
The demographics of sub-Jovian planets around low-mass stars is dominated by populations of ``sub-Neptunes" and ``super-Earths", distinguished by the presence or absence of envelop…
Suppression of hydrodynamic escape of an H2-rich early Earth atmosphere by radiative cooling of carbon oxides
Tatsuya Yoshida, Naoki Terada, Kiyoshi Kuramoto
Radiative cooling by molecules is a crucial process for hydrodynamic escape, as it can efficiently remove the thermal energy driving the outflow, acquired through X-ray and extreme…
Self-Shielding Enhanced Organics Synthesis in an Early Reduced Earth's Atmosphere
Tatsuya Yoshida, Shungo Koyama, Yuki Nakamura +2
Earth is expected to have acquired a reduced proto-atmosphere enriched in H2 and CH4 through the accretion of building blocks that contain metallic Fe and/or the gravitational trap…