Article
Astronomy & Astrophysics
B. Charnay, G. Tobie, S. Lebonnois, R. D. Lorenz
Summary: By studying Titan's atmosphere, the Dragonfly mission can provide valuable constraints on the interior of Titan.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
M. Rengel, D. Shulyak, P. Hartogh, H. Sagawa, R. Moreno, C. Jarchow, D. Breitschwerdt
Summary: The aim of this study was to measure the vertical distribution of HCN on Titan's stratosphere using ground-based submillimetre observations acquired quasi-simultaneously with the Herschel ones. The results showed consistent HCN abundance profiles and provided valuable information for the improvement of photochemical models. The study received a score of 9 out of 10 for its importance in understanding the vertical distribution of HCN in Titan's stratosphere.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
N. L. Rossignoli, R. P. Di Sisto, M. G. Parisi
Summary: By studying the impact crater counts and erosion processes on Titan, we can estimate its surface age and understand the role of centaur objects in impacts.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Benno A. Neuenschwander, Ravit Helled
Summary: This paper presents empirical structure models of Uranus and Neptune and predicts their rotation periods and wind depths by using higher order gravitational coefficients. The study finds that faster rotation and deep winds favor centrally concentrated density distributions. Accurate measurements of the gravity field and moment of inertia can constrain their internal structures and wind depths.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Yutian Cao, Dandan Niu, Wenjun Liang, Jun Cui, Xiaoshu Wu, Xin Wan, Jiahao Zhong, Lei Li, Zhaojin Rong, Yong Wei
Summary: Thermal electron depression and energetic electron depletion are observed in the nightside Martian ionosphere. While energetic electron depletion has been extensively studied, there is limited research on thermal electron depression and the correlation between the two is unknown. Through Mars Express total electron content (TEC) measurements, a large number of TEC depression features are identified, with large amplitude depression being more frequently observed near strong magnetic fields and small amplitude depression uniformly distributed across the Martian surface.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Ludwig Scheibe, Nadine Nettelmann, Ronald Redmer
Summary: Thermal evolution models of Uranus and Neptune suggest that their luminosities are inconsistent with the classical assumption of an adiabatic interior, with the influence of a thermally conductive boundary layer being a significant factor. Even a thin conductive layer of a few kilometers can greatly affect planetary cooling, resulting in either brighter or fainter appearances compared to the adiabatic case. The models also indicate that Uranus may have been in equilibrium with solar flux for a longer period of time.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Richard Hobbs, Paul B. Rimmer, Oliver Shorttle, Nikku Madhusudhan
Summary: A new network of atmospheric sulfur reactions was proposed and validated, showing significant impact on gas mixing ratios under specific conditions and causing major changes in the abundance of specific species. Accurate understanding of sulfur chemistry in hot and warm Jupiter atmospheres requires experimental measurements of reaction rates.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Hao Gu, Jun Cui, Dandan Niu, Jiang Yu
Summary: The study suggests that on Venus, collision by hot O likely plays a dominant role in driving total atmospheric hydrogen and helium escape at the present epoch, with a reduction in escape flux for all species during high solar activities. Substantial variations are also revealed by the calculations.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Xu Huang, Hao Gu, Jun Cui, Xiaoshu Wu, Mingyang Sun
Summary: This study evaluates the effects of the 2018 global dust storm on the photochemical escape of atomic C, N, and O on Mars. It uses multi-instrument measurements and a one-dimensional Monte Carlo model to calculate the escape probability profile and derive the photochemical escape rates. The results show that the GDS-induced C, N, and O escape is generally reduced by about 30-40% compared to the pre-GDS state, contrary to the well-known result of GDS-induced strong enhancement of atomic H escape.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Ye Yuan, Fan Li, Yanning Fu, Jian Chen
Summary: Through new observations and ephemerides, a dynamic model update has effectively improved the ephemerides for Triton and Nereid. The model fitting process led to the determination of Neptune's pole orientation, providing refined geometric descriptions.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
M. Lampon, M. Lopez-Puertas, S. Czesla, A. Sanchez-Lopez, L. M. Lara, M. Salz, J. Sanz-Forcada, K. Molaverdikhani, A. Quirrenbach, E. Palle, J. A. Caballero, Th. Henning, L. Nortmann, P. J. Amado, D. Montes, A. Reiners, I. Ribas
Summary: Hydrodynamic escape is the most efficient atmospheric mechanism of planetary mass loss, with three regimes identified: energy-limited, recombination-limited, and photon-limited. This study provides evidence of these regimes in exoplanets HD 209458 b, HD 189733 b, and GJ 3470 b.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
L. Fossati, F. Biassoni, G. M. Cappello, F. Borsa, D. Shulyak, A. S. Bonomo, D. Gandolfi, F. Haardt, T. Koskinen, A. F. Lanza, V. Nascimbeni, D. Sicilia, M. Young, G. Aresu, A. Bignamini, M. Brogi, I. Carleo, R. Claudi, R. Cosentino, G. Guilluy, C. Knapic, L. Malavolta, L. Mancini, D. Nardiello, M. Pinamonti, L. Pino, E. Poretti, M. Rainer, F. Rigamonti, A. Sozzetti
Summary: This study aims to extract the transmission spectrum of the HI Balmer lines of the ultra-hot Jupiter KELT-20b/MASCARA-2b and compare it with the results obtained through forward modeling. Line profiles were extracted from six transits observed with the HARPS-N high-resolution spectrograph. The synthetic transmission spectrum derived from the NLTE TP profile is in good agreement with the observed HI Balmer line profiles, validating the obtained atmospheric structure.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
T. Azevedo Silva, O. D. S. Demangeon, N. C. Santos, R. Allart, F. Borsa, E. Cristo, E. Esparza-Borges, J. Seidel, E. Palle, S. G. Sousa, H. M. Tabernero, M. R. Zapatero Osorio, S. Cristiani, F. Pepe, R. Rebolo, V Adibekyan, Y. Alibert, S. C. C. Barros, F. Bouchy, V Bourrier, G. Lo Curto, P. Di Marcantonio, V D'Odorico, D. Ehrenreich, P. Figueira, J. I. Gonzalez Hernandez, C. Lovis, C. J. A. P. Martins, A. Mehner, G. Micela, P. Molaro, D. Mounzer, N. J. Nunes, A. Sozzetti, A. Suarez Mascareno, S. Udry
Summary: This article investigates the atmospheric compositions and dynamics of two ultra-hot Jupiters, WASP-76b and WASP-121b. By reanalyzing the transit observations, novel species including Ba +, Co, Sr +, and tentative detection of Ti + are discovered, expanding the known atmospheric compositions of these exoplanets.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
H. Gu, J. Cui, D. -D. Niu, X. -S. Wu, F. He, Y. Wei
Summary: The study evaluates the role of chemically induced escape on Triton and identifies dominant processes for various species. Chemical escape rates for H, C, N, and O are calculated, indicating significant contributions to N and O escape on Triton.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
T. Cavalie, B. Benmahi, V. Hue, R. Moreno, E. Lellouch, T. Fouchet, P. Hartogh, L. Rezac, T. K. Greathouse, G. R. Gladstone, J. A. Sinclair, M. Dobrijevic, F. Billebaud, C. Jarchow
Summary: In this study, wind speeds in Jupiter's stratosphere were measured to bridge the altitude gap between the tropospheric and ionospheric wind patterns. Zonal jets were detected at low-to-mid latitudes, while nonzonal winds were found at polar latitudes, potentially aiding in chemical complexification processes.
ASTRONOMY & ASTROPHYSICS
(2021)