Results 41 to 50 of about 1,731,322 (198)

The coronagraphic Modal Wavefront Sensor: a hybrid focal-plane sensor for the high-contrast imaging of circumstellar environments [PDF]

, 2020
The raw coronagraphic performance of current high-contrast imaging instruments is limited by the presence of a quasi-static speckle (QSS) background, resulting from instrumental Non-Common Path Errors (NCPEs).
Pietrow, A, Snik, Frans, Keller, Christoph U, Wilby, M J, Korkiakoski, Visa   +4 more
core   +3 more sources

Risk Assessment of the Ground Magnetic Response to the March and April 2023 Geomagnetic Storms Using Geomagnetically Induced Currents Indices

Space Weather, Volume 23, Issue 4, April 2025.
Abstract We analyzed the solar origin and ground response during the severe geomagnetic storms (GSs) of 23–24 March (GS1) and 23–24 April 2023 (GS2) using Geomagnetically Induced Currents Indices (GIC indices) computed from geomagnetic field data. The GSs were initiated by erupting filaments and associated slow (fast) halo coronal mass ejections on 20 ...
Paul O. Amaechi, Honore Messanga, Frank O. Grodji, Andrew Akala, Irina Despirak, Chigomezyo M. Ngwira, Elijah Oyeyemi, Christine Amory‐Mazaudier   +7 more
wiley   +1 more source

Faster imaging simulation through complex systems: a coronagraphic example

, 2020
End-to-end simulation of the influence of the optical train on the observed scene is important across optics and is particularly important for predicting the science yield of astronomical telescopes.
Douglas, Ewan S., Milani, Kian
core   +1 more source

Probing the Outskirts of M Dwarf Planetary Systems with a Cycle 1 JWST NIRCam Coronagraphy Survey

The Astronomical Journal
The population of giant planets on wide orbits around low-mass M dwarf stars is poorly understood, but the unprecedented sensitivity of JWST NIRCam coronagraphic imaging now provides direct access to planets significantly less massive than Jupiter beyond
Ellis Bogat, Joshua E. Schlieder, Kellen D. Lawson, Yiting Li, Jarron M. Leisenring, Michael R. Meyer, William Balmer, Thomas Barclay, Charles A. Beichman, Geoffrey Bryden, Per Calissendorff, Aarynn L. Carter, Matthew De Furio, Julien H. Girard, Thomas P. Greene, Tyler D. Groff, Jens Kammerer, Jorge Llop-Sayson, Michael W. McElwain, Marcia J. Rieke, Marie Ygouf   +20 more
doaj   +1 more source

Searching for Planets Orbiting Fomalhaut with JWST/NIRCam

The Astronomical Journal, 2023
We report observations with the JWST/NIRCam coronagraph of the Fomalhaut ( α PsA) system. This nearby A star hosts a complex debris disk system discovered by the IRAS satellite.
Marie Ygouf, Charles A. Beichman, Jorge Llop-Sayson, Geoffrey Bryden, Jarron M. Leisenring, András Gáspár, John E. Krist, Marcia J. Rieke, George H. Rieke, Schuyler Grace Wolff, Thomas L. Roellig, Kate Su, Kevin N. Hainline, Klaus W. Hodapp, Thomas P. Greene, Michael R. Meyer, Douglas M. Kelly, Karl Misselt, John Stansberry, Martha Boyer, Doug Johnstone, Scott Horner, Alexandra Z. Greenbaum   +22 more
doaj   +1 more source

Three-polarizer Treatment of Linear Polarization in Coronagraphs and Heliospheric Imagers

The Astrophysical Journal, 2022
Abstract Linearly polarized light has been used to view the solar corona for over 150 years. While the familiar Stokes representation for polarimetry is complete, it is best matched to a laboratory setting and therefore is not the most convenient representation either for coronal instrument design or for coronal data analysis.
Craig E. DeForest, Daniel B. Seaton, Matthew J. West   +2 more
openaire   +2 more sources

Decent Estimate of CME Arrival Time From a Data‐Assimilated Ensemble in the Alfvén Wave Solar Atmosphere Model (DECADE‐AWSoM)

Space Weather, Volume 23, Issue 1, January 2025.
Abstract Forecasting the arrival time of Earth‐directed coronal mass ejections (CMEs) via physics‐based simulations is an essential but challenging task in space weather research due to the complexity of the underlying physics and limited remote and in situ observations of these events. Data assimilation techniques can assist in constraining free model
Hongfan Chen, Nishtha Sachdeva, Zhenguang Huang, Bart van der Holst, Ward Manchester IV, Aniket Jivani, Shasha Zou, Yang Chen, Xun Huan, Gabor Toth   +9 more
wiley   +1 more source

SCExAO/CHARIS Multiwavelength High-contrast Imaging of the BD+45°598 Debris Disk

The Astronomical Journal
We present a multiwavelength (1.16–2.37 μ m) view of the debris disk around BD+45 ^° 598, using the Subaru Coronagraphic Extreme Adaptive Optics system paired with the Coronagraphic High Angular Resolution Imaging Spectrograph.
Maria Vincent, Kellen Lawson, Thayne Currie, Jonathan P. Williams, Olivier Guyon, Julien Lozi, Vincent Deo, Sébastien Vievard   +7 more
doaj   +1 more source

Mitigating Worst-case Exozodiacal Dust Structure in High-contrast Images of Earth-like Exoplanets

The Astronomical Journal, 2023
Detecting Earth-like exoplanets in direct images of nearby Sun-like systems brings a unique set of challenges that must be addressed in the early phases of designing a space-based direct imaging mission.
Miles H. Currie, Christopher C. Stark, Jens Kammerer, Roser Juanola-Parramon, Victoria S. Meadows   +4 more
doaj   +1 more source

Jovian Sodium Nebula and Io Plasma Torus S+ and Brightnesses 2017–2023: Insights Into Volcanic Versus Sublimation Supply

Journal of Geophysical Research: Space Physics, Volume 129, Issue 3, March 2024.
Abstract We present first results derived from the largest collection of contemporaneously recorded Jovian sodium nebula and Io plasma torus in [S II] 6731 Å images assembled to date. The data were recorded by the Planetary Science Institute's Io Input/Output observatory and provide important context to Io geologic and atmospheric studies as well as ...
Jeffrey P. Morgenthaler, Carl A. Schmidt, Marissa F. Vogt, Nicholas M. Schneider, Max Marconi   +4 more
wiley   +1 more source