Search Publications
An Electric-field-driven Global Coronal Magnetohydrodynamics Simulation Model Using Helioseismic and Magnetic Imager Vector-magnetic-field Synoptic Map Data
Hayashi, Keiji; Wu, Chin-Chun; Liou, Kan
We present the simulation methodology and results of our new data-driven global coronal magnetohydrodynamics (MHD) simulation model. In this model, the solar-surface electric field is first calculated such that the curl will satisfy both the induction equation and the given temporal variations of the solar-surface magnetic field. We use the synopt…
Gaia-predicted brown dwarf detection rates around FGK stars in astrometry, radial velocity, and photometric transits
Holl, B.; Lindegren, L.; Perryman, M. +2 more
Context. After more than two decades of relevant radial velocity surveys, the current sample of known brown dwarfs (BDs) around FGK stars is only of the order of 100, limiting our understanding of their occurrence rate, properties, and formation. The ongoing ESA mission Gaia has already collected more than its nominal 5 years of mission data, and …
New Theoretical Period-Luminosity-Metallicity Relations for RR Lyrae in the Rubin-LSST Filters
Marconi, Marcella; Molinaro, Roberto; Dall'Ora, Massimo +8 more
The revolutionary power of future Rubin-LSST observations will allow us to significantly improve the physics of pulsating stars, including RR Lyrae. In this context, an updated theoretical scenario predicting all the relevant pulsation observables in the corresponding photometric filters is mandatory. The bolometric light curves are based on a rec…
A Simple Condensation Model for the H2SO4-H2O Gas-Cloud System on Venus
Shao, Wencheng D.; Zhang, Xi; Cui, Jun +2 more
The current Venus climate is largely regulated by globally covered concentrated sulfuric acid clouds from binary condensation of sulfuric acid (H2SO4) and water (H2O). To understand this complicated H2SO4-H2O gas-cloud system, previous theoretical studies either adopted complicated …
The POKEMON Speckle Survey of Nearby M Dwarfs. I. New Discoveries
Kiman, Rocio; Ciardi, David R.; Clark, Catherine A. +4 more
M dwarfs are favorable targets for exoplanet detection with current instrumentation, but stellar companions can induce false positives and inhibit planet characterization. Knowledge of stellar companions is also critical to our understanding of how binary stars form and evolve. We have therefore conducted a survey of stellar companions around near…
The Extended Tidal Tails of NGC 7089 (M2)
Grillmair, Carl J.
Using photometry and proper motions from Gaia Early Data Release 3, we detect a 45° long trailing stellar debris stream associated with the old, metal-poor globular cluster NGC 7089. With a width on the order of 100 pc, the extended stream appears to be as dynamically cold as the coldest known streams found to date. There is some evidence for an e…
Blue Stragglers as Tracers of the Dynamical State of Two Clusters in the Small Magellanic Cloud: NGC 339 and NGC 419
Dalessandro, E.; Massari, D.; Ferraro, F. R. +5 more
The level of central segregation of Blue Straggler stars has proved to be an excellent tracer of the dynamical evolution of old star clusters (the so-called "dynamical clock"), both in the Milky Way and in the Large Magellanic Cloud. The A + parameter, used to measure the Blue Stragglers degree of segregation, has in fact been found to …
Milky Way Zero-point Calibration of the JAGB Method: Using Thermally Pulsing AGB Stars in Galactic Open Clusters
Madore, Barry F.; Freedman, Wendy L.; Lee, Abigail J. +1 more
We present a new calibration of the J-band absolute magnitude of the JAGB method based on thermally pulsing AGB stars that are members of Milky Way open clusters, having distances and reddenings, independently compiled and published by Marigo. A total 17 of these photometrically selected J-Branch AGB stars give M J = -6.40 mag with a …
The M3 project: 3 - Global abundance distribution of hydrated silicates at Mars
Poulet, François; Riu, Lucie; Carter, John
This paper is the third paper of a series that provides the modal mineralogy of the Martian surface (M3 project) at the global scale using near-infrared hyperspectral imagery. Numerous locations at the surface of Mars have previously been identified to harbor hydrated minerals which offer unique insights on the past water activity at th…
Impact of the image alignment over frequency for the VLBI Global Observing System
Xu, Ming H.; Savolainen, Tuomas; Anderson, James M. +4 more
Aims: The VLBI Global Observing System (VGOS), which is the next generation of geodetic very long baseline interferometry (VLBI), observes simultaneously in four frequency bands in the range 3.0-10.7 GHz (expected to be extended to 14 GHz). Because source structure changes with frequency, we aim to study the source position estimates from the…