Search Publications
Comparing and Contrasting the Properties of the Inner Heliosphere for the Three Most Recent Solar Minima
Downs, Cooper; Riley, Pete; Linker, Jon A. +2 more
The previous three solar cycles have ended in progressively more quiescent conditions, suggesting a continual slide into an ever deeper minimum state. Although the Sun's magnetic field is undoubtedly responsible for this quiescence, it is not clear how changes in its structure and strength modulate the properties of the solar wind. In this study, …
CWISE J014611.20-050850.0AB: The Widest Known Brown Dwarf Binary in the Field
Shkolnik, Evgenya; Meisner, Aaron M.; Cushing, Michael C. +17 more
While stars are often found in binary systems, brown dwarf binaries are much rarer. Brown dwarf-brown dwarf pairs are typically difficult to resolve because they often have very small separations. Using brown dwarfs discovered with data from the Wide-field Infrared Survey Explorer (WISE) via the Backyard Worlds: Planet 9 citizen science project, w…
Climatology of the CO Vertical Distribution on Mars Based on ACS TGO Measurements
Montmessin, Franck; Trokhimovskiy, Alexander; Alday, Juan +13 more
Carbon monoxide is a non-condensable gas in the Martian atmosphere produced by the photolysis of CO2. Its abundance responds to the condensation and sublimation of CO2 from the polar caps, resulting in seasonal variations of the CO mixing ratio. ACS onboard the ExoMars Trace Gas Orbiter have measured CO in infrared bands by s…
Is the Core-cusp Problem a Matter of Perspective? Jeans Anisotropic Modeling against Numerical Simulations
Tian, Hao; Grand, Robert J. J.; Wang, Wenting +14 more
Mock member stars for 28 dwarf galaxies are constructed from the cosmological AURIGA simulation, which reflects the dynamical status of realistic stellar tracers. Axisymmetric Jeans Anisotropic Multi-Gaussian Expansion (JAM) modeling is applied to 6000 star particles for each system to recover the underlying matter distribution. The stellar or dar…
The role and contribution of magnetic fields, characterized via their magnetic flux, to the statistical structuring of the solar atmosphere
Li, K. J.; Xu, J. C.; Feng, W.
The anomalous heating of the solar upper atmosphere is one of the eight key problems in modern astronomy. Moreover, the stratification of the solar atmosphere is an outstanding key-problem in solar physics. In this study, a hot butterfly-like pattern is found to run through the chromosphere to the corona lying right on top of the magnetic butterfl…
Estimating the Convective Turnover Time
Henry, Todd J.; Wright, Nicholas J.; Jao, Wei-Chun +2 more
The introduction of the Rossby number (R0), which incorporates the convective turnover time (τ), in 1984 was a pioneering idea for understanding the correlation between stellar rotation and activity. The convective turnover time, which cannot be measured directly, is often inferred using existing τ-mass or τ-color relations, typically e…
Circular Polarization Observations of Type II Solar Radio Bursts and the Coronal Magnetic Field
Ramesh, R.; Kathiravan, C.; Chellasamy, E. Ebenezer
It is well known that magnetic field strength (B) in the solar corona can be calculated using the Alfvén Mach number (M A ) and Alfvén speed (v A ) of the magnetohydrodynamic shock waves associated with coronal type II radio bursts. We show that observations of weak circularly polarized emission associated with the harmonic…
The impact of turbulent vertical mixing in the Venus clouds on chemical tracers
Marcq, Emmanuel; Lefèvre, Franck; Lefèvre, Maxence
Venus' clouds host a convective layer between roughly 50 and 60 km that mixes heat, momentum, and chemical species. Observations and numerical modelling have helped to understand the complexity of this region. However, the impact on chemistry is still not known. Here, we use for the first time a three-dimensional convection-resolving model with pa…
Kinematics of luminous blue variables in the Large Magellanic Cloud
Choi, Yumi; Smith, Nathan; Andrews, Jennifer +3 more
We study the kinematics of luminous blue variables (LBVs) in the Large Magellanic Cloud (LMC). Using high-resolution spectra, we measure the systemic radial velocities for a sample of 16 LBVs and LBV candidates. In order to measure the net motion of LBVs compared to their local environments, we subtract the projected line-of-sight velocity at the …
Searching for a Solar Source of Magnetic-Field Switchbacks in Parker Solar Probe's First Encounter
Mandrini, C. H.; Raouafi, N. E.; Velli, M. +9 more
Parker Solar Probe observations show ubiquitous magnetic-field reversals closer to the Sun, often referred to as "switchbacks". The switchbacks have been observed before in the solar wind near 1 AU and beyond, but their occurrence was historically rare. PSP measurements below ∼ 0.2 AU show that switchbacks are, however, the most prominent structur…