Search Publications
β Cephei Pulsations in the High-mass Eclipsing System CW Cephei
Hong, Kyeongsoo; Lee, Jae Woo
CW Cep is an early B-type eclipsing binary with mass measurement precisions better than 1%. We report the discovery of pulsation signatures in the Transiting Exoplanet Survey Satellite time-series data of the system observed during Sectors 17 and 18. Our binary modeling indicates that the target star is a partially eclipsing detached system with m…
Reconstructing Substorms via Historical Data Mining: Is It Really Feasible?
Sitnov, M. I.; Tsyganenko, N. A.; Stephens, G. K. +4 more
The evolution of the low-latitude magnetosphere over the substorm cycle is reconstructed based on a new high-resolution 3D representation of the magnetic field and nearest-neighbor data mining. The study covers radial distances 2.5-25 RE and employs a record-large pool of spacecraft data taken during 1995-2019. The magnetospheric state …
Dynamics of recent landslides (<20 My) on Mars: Insights from high-resolution topography on Earth and Mars and numerical modelling
Mangold, N.; Pajola, M.; Cremonese, G. +13 more
Landslides are common features found on steep slopes on Mars and the role of water in their formation is an open question. Our study focuses on three young martian landslides whose mechanism of formation is unknown and knowing their formation mechanism could give us key information on recent martian climate and/or tectonics. They are less than 5 k…
The orbital evolution of UFDs and GCs in an evolving Galactic potential
Bekki, Kenji; Armstrong, Benjamin M.; Ludlow, Aaron D.
We use the second Gaia data release to investigate the kinematics of 17 ultra-faint dwarf galaxies (UFDs) and 154 globular clusters (GCs) in the Milky Way, focusing on the differences between static and evolving models of the Galactic potential. An evolving potential modifies a satellite's orbit relative to its static equivalent, though the differ…
Gas clumping in the outskirts of the Virgo cluster
Walker, S. A.; Mirakhor, M. S.
Observations of the intracluster medium (ICM) in the outskirts of the Virgo cluster with Suzaku have found the gas mass fraction in the northern direction to be significantly above the expected level, indicating that there may be a very high level of gas clumping on small scales in this direction. Here we explore the XMM-Newton data in the outskir…
An improved model for the spectra of discs of nova-like variables
Hubeny, Ivan; Long, Knox S.
The spectra arising from the discs of nova-like variables show many of the features seen in stellar atmospheres. They are typically modelled either from an appropriated weighted set of stellar atmospheres or a disc atmosphere with energy is dissipated near the disc plane, with the effective temperature distribution expected from a steady-state acc…
An Explanation of the Nightside Ionospheric Structure of Venus
Brecht, Stephen H.; Ledvina, Stephen A.
Hybrid simulations of Venus have produced nightside structure. It is believed these are the first simulations to produce the structure reported by spacecraft such as the Pioneer Venus Orbiter (PVO). The simulations reveal that the structure is created by the ▽Pe ambipolar electric field when it aligns with local IMF (interplanetary magn…
CO isotopolog line fluxes of viscously evolving disks. Cold CO conversion insufficient to explain observed low fluxes
van Dishoeck, E. F.; Rosotti, G.; Trapman, L. +2 more
Context. Protoplanetary disks are thought to evolve viscously, where the disk mass - the reservoir available for planet formation - decreases over time as material is accreted onto the central star over a viscous timescale. Observations have shown a correlation between disk mass and the stellar mass accretion rate, as expected from viscous theory.…
Polarization of hot Jupiter systems: a likely detection of stellar activity and a possible detection of planetary polarization
Bailey, Jeremy; Cotton, Daniel V.; Kedziora-Chudczer, Lucyna +6 more
We present high-precision linear polarization observations of four bright hot Jupiter systems (τ Boo, HD 179949, HD 189733, and 51 Peg) and use the data to search for polarized reflected light from the planets. The data for 51 Peg are consistent with a reflected light polarization signal at about the level expected with 2.8σ significance and a fal…
Impact of foreshock transients on the flank magnetopause and magnetosphere and the ionosphere
Wang, Chih-Ping; Wang, Xueyi; Liu, Terry Z. +1 more
Mesoscale (on the scales of a few minutes and a few RE) magnetosheath and magnetopause perturbations driven by foreshock transients have been observed in the flank magnetotail. In this paper, we present the 3D global hybrid simulation results to show qualitatively the 3D structure of the flank magnetopause distortion caused by foreshock transients…