Results 21 to 30 of about 962 (206)

A Quarter Century of Wind Spacecraft Discoveries

Reviews of Geophysics, Volume 59, Issue 2, June 2021., 2021
Abstract The Wind spacecraft, launched on November 1, 1994, is a critical element in NASA’s Heliophysics System Observatory (HSO)—a fleet of spacecraft created to understand the dynamics of the Sun‐Earth system. The combination of its longevity (>25 years in service), its diverse complement of instrumentation, and high resolution and accurate ...
Lynn B. Wilson III, Alexandra L. Brosius, Natchimuthuk Gopalswamy, Teresa Nieves‐Chinchilla, Adam Szabo, Kevin Hurley, Tai Phan, Justin C. Kasper, Noé Lugaz, Ian G. Richardson, Christopher H. K. Chen, Daniel Verscharen, Robert T. Wicks, Jason M. TenBarge   +13 more
wiley   +1 more source

CME Magnetic Structure and IMF Preconditioning Affecting SEP Transport

Space Weather, Volume 19, Issue 4, April 2021., 2021
Abstract Coronal mass ejections (CMEs) and solar energetic particles (SEPs) are two phenomena that can cause severe space weather effects throughout the heliosphere. The evolution of CMEs, especially in terms of their magnetic structure, and the configuration of the interplanetary magnetic field (IMF) that influences the transport of SEPs are currently
Erika Palmerio, Emilia K. J. Kilpua, Olivier Witasse, David Barnes, Beatriz Sánchez‐Cano, Andreas J. Weiss, Teresa Nieves‐Chinchilla, Christian Möstl, Lan K. Jian, Marilena Mierla, Andrei N. Zhukov, Jingnan Guo, Luciano Rodriguez, Patrick J. Lowrance, Alexey Isavnin, Lucile Turc, Yoshifumi Futaana, Mats Holmström   +17 more
wiley   +1 more source

Assessing the Projection Correction of Coronal Mass Ejection Speeds on Time‐of‐Arrival Prediction Performance Using the Effective Acceleration Model

Space Weather, Volume 19, Issue 2, February 2020., 2021
Abstract White light images of coronal mass ejections (CMEs) are projections on the plane‐of‐sky (POS). As a result, CME kinematics are subject to projection effects. The error in the true (deprojected) speed of CMEs is one of the main causes of uncertainty to Space Weather forecasts, since all estimates of the CME time‐of‐arrival (ToA) at a certain ...
Evangelos Paouris, Angelos Vourlidas, Athanasios Papaioannou, Anastasios Anastasiadis   +3 more
wiley   +1 more source

Deriving CME Density From Remote Sensing Data and Comparison to In‐Situ Measurements

Journal of Geophysical Research: Space Physics, Volume 126, Issue 1, January 2021., 2021
Abstract We determine the three‐dimensional geometry and deprojected mass of 29 well‐observed coronal mass ejections (CMEs) and their interplanetary counterparts (ICMEs) using combined Solar Terrestrial Relations Observatory ‐ Solar and Heliospheric Observatory white‐light data.
M. Temmer, L. Holzknecht, M. Dumbović, B. Vršnak, N. Sachdeva, S. G. Heinemann, K. Dissauer, C. Scolini, E. Asvestari, A. M. Veronig, S. J. Hofmeister   +10 more
wiley   +1 more source

The Subaru coronagraphic extreme AO (SCExAO) system: Visible imaging mode [PDF]

, 2020
The Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system is an instrument designed to be inserted between the Subaru AO188 system and the infrared HiCIAO camera in order to greatly improve the contrast in the very close (less than 0.5 ...
Martinache, Frantz, Baudoz, Pierre, Kaito, Yokochi, Garrel, Vincent, Cantalloube, Faustine, Guyon, Olivier, Vogt, Frédéric P.A., Takashi, Yoshikawa   +7 more
core   +1 more source

Performance of the near-infrared coronagraphic imager on Gemini-South [PDF]

SPIE Proceedings, 2008
We present the coronagraphic and adaptive optics performance of the Gemini-South Near-Infrared Coronagraphic Imager (NICI). NICI includes a dual-channel imager for simultaneous spectral difference imaging, a dedicated 85-element curvature adaptive optics system, and a built-in Lyot coronagraph.
Chun, Mark, Toomey, Doug, Wahhaj, Zahed, Biller, Beth, Artigau, Etienne, Hayward, Tom, Liu, Mike, Close, Laird, Hartung, Markus, Rigaut, Francois, Ftaclas, Christ   +10 more
openaire   +2 more sources

Square Root Compression and Noise Effects in Digitally Transformed Images

The Astrophysical Journal, 2022
We report on a particular example of noise and data representation interacting to introduce systematic error into scientific measurements. Many instruments collect integer digitized values and apply nonlinear coding, in particular square root coding, to ...
Craig E. DeForest, Chris Lowder, Daniel B. Seaton, Matthew J. West   +3 more
doaj   +1 more source

Wavefront Sensing by a Common-Path Interferometer for Wavefront Correction in Phase and Amplitude by a Liquid Crystal Spatial Light Modulator Aiming the Exoplanet Direct Imaging

Photonics, 2023
We implemented the common-path achromatic interfero-coronagraph both for the wavefront sensing and the on-axis image component suppression, aiming for the stellar coronagraphy.
Andrey Yudaev, Alexander Kiselev, Inna Shashkova, Alexander Tavrov, Alexander Lipatov, Oleg Korablev   +5 more
doaj   +1 more source

Space Weather Monitor at the L5 Point: A Case Study of a CME Observed with STEREO B

Space Weather, Volume 18, Issue 10, October 2020., 2020
Abstract An important location for future space weather monitoring is the Lagrange point 5 (L5) of the Sun‐Earth system. We test the performance of L5 for space weather monitoring using STEREO B observations of an Earth‐directed coronal mass ejection (CME), seen as a partial halo by SOHO at L1.
L. Rodriguez, C. Scolini, M. Mierla, A. N. Zhukov, M. J. West   +4 more
wiley   +1 more source

High-contrast imaging results with the vortex coronagraph [PDF]

SPIE Proceedings, 2013
The vortex coronagraph has already enabled high-contrast observations very close to bright stars on large ground-based telescopes, and it also has great potential for use on coronagraphic space missions aimed at exoplanet detection and characterization.
Serabyn, E., Trauger, J., Moody, D., Mawet, D., Liewer, K., Krist, J., Kern, B.   +6 more
openaire   +2 more sources