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Simultaneous Estimates of Star-cluster Age, Metallicity, Mass, and Extinction (SESAMME). I. Presenting an MCMC Approach to Spectral Stellar Population Fitting
Hernandez, Svea; Smith, Linda J.; Aloisi, Alessandra +3 more
We present the first version release of SESAMME, a public, Python-based full spectrum fitting tool for Simultaneous Estimates of Star-cluster Age, Metallicity, Mass, and Extinction. SESAMME compares an input spectrum of a star cluster to a grid of stellar population models with an added nebular continuum component, using Markov Chain Monte Carlo m…
Multipoint Detection of GRB221009A's Propagation through the Heliosphere
Wilson, Lynn; Balikhin, Michael; Larson, Davin +9 more
We present the results of processing the effects of the powerful gamma-ray burst GRB221009A captured by the charged particle detectors (electrostatic analyzers and solid-state detectors) on board spacecraft at different points in the heliosphere on 2022 October 9. To follow the GRB221009A propagation through the heliosphere, we used the electron a…
The m-dimensional spatial Nyquist limit using the wave telescope for larger numbers of spacecraft
Motschmann, Uwe; Plaschke, Ferdinand; Glassmeier, Karl-Heinz +2 more
Spacecraft constellations consisting of multiple satellites are becoming more and more interesting not only for commercial use but also for space science missions. The proposed and accepted scientific multi-satellite missions that will operate within Earth's magnetospheric environment, like HelioSwarm, require researchers to extend established met…
Super rogue waves at Venusian ionosphere and mantle
El-Shafeay, N. A.; El-Taibany, W. F.; Moslem, W. M. +1 more
Formation of super rogue ion-acoustic wave is suggested as a physical catalyst for the photochemical reaction to form the Venusian ionosphere and its mantle. Based on the observed data at Venus by Pioneer Venus Orbiter (PVO) and Venus Express (VEX), we constructed our models. The plasma model of the ionosphere consists of two positive ions fluid (…
The Sun as a revolving-field magnetic alternator with a wobbling-core rotator from real data
Omerbashich, Mensur
Rather than as a star classically assumed to feature elusive dynamo or a proverbial engine and impulsively alternating polarity, the Sun reveals itself in the 385.8–2.439-nHz (1-month–13-years) band of polar (φSun>|70°|) wind's decadal dynamics, dominated by the fast (>700 km s^‑1) winds, as a globally completely vibrating revolving-field ma…
Quasi‑periodic oscillations are more than timing features: Applying the accretion‑ejection instability in super massive black‑holes
Varniere, Peggy
Low frequency quasi‑periodic oscillations (LFQPOs) have always been seen uniquely as a timing feature, with most models focused on reproducing only their timing behavior. Previously, the accretion‑ejection instability (AEI) predicted the existence of a more subtle effect on their energy spectrum. In the case of low mass X‑ray binaries (LMXB), that…
A Six Year, Low-resolution, Multibroadband Transit Photometry Study of HD 189733b
Piccone, Ashley N.; Kobulnicky, Henry A.; Jang-Condell, Hannah +13 more
Transmission spectroscopy offers an invaluable opportunity to characterize the atmospheres of exoplanets. We present new ground-based optical transmission spectra of the hot Jupiter HD 189733b, derived from nine transits observed over a six year time span (2016-2021) using near-simultaneous $u^{\prime} g^{\prime} r^{\prime} i^{\prime} $ broadband …
Monitoring Hα Emission from the Wide-orbit Brown-dwarf Companion FU Tau B
Bowler, Brendan P.; Close, Laird M.; Wu, Ya-Lin +5 more
Monitoring mass accretion onto substellar objects provides insights into the geometry of the accretion flows. We use the Lulin One-meter Telescope to monitor Hα emission from FU Tau B, a ~19 M Jup brown-dwarf companion at 5.″7 (719 au) from the host star, for six consecutive nights. This is the longest continuous Hα monitoring for a sub…
Non-universality of the Turbulent Spectra at Sub-ion Scales in the Solar Wind: Dispersive Effects versus the Doppler Shift
Sahraoui, Fouad; Huang, Shiyong
Large surveys of the power spectral density of the magnetic fluctuations in the solar wind have reported different slope distributions at MHD, sub-ion and sub-electron scales: the smaller the scale, the broader the distribution. Here, we review briefly some of the most relevant explanations of the broadening of the slopes at sub-ion scales. Then, …
M dwarf stars in the b294 field from the VISTA Variables in the Vía Láctea (VVV)
Minniti, Dante; Alonso-García, Javier; Saito, Roberto K. +4 more
M dwarf stars are the dominant stellar population in the Milky Way, and they are important for a wide variety of astrophysical topics. The Gaia mission has delivered a superb collection of data, nevertheless, ground-based photometric surveys are still needed to study faint objects. Therefore, the present work aims to identify and characterize M dw…