Results 31 to 40 of about 221 (177)

On Some Properties of SEP Effective CMEs

International Scholarly Research Notices, Volume 2011, Issue 1, 2011., 2011
Solar energetic particles (SEP) are believed to originate from two different sources, solar flares and coronal mass ejections (CMEs). The large SEP events constitute a serious radiation hazard. The high‐energy solar proton data obtained from NOAA Space Environment Services Center are used to investigate some statistical properties such as speed ...
Nishant Mittal, Anshu Gupta, P. S. Negi, Udit Narain, M. Richmond   +4 more
wiley   +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

Coronagraphic Imaging of 3C 273 with the Advanced Camera for Surveys

The Astronomical Journal, 2003
The nearby and luminous QSO 3C 273 was imaged in 2002 July with the High Resolution Channel (HRC) of the Advanced Camera for Surveys (ACS) in coronagraphic mode in F475W (g), F606W (V), and F814W (I) as part of the Early Release Observations (ERO) program.
Martel AR, Ford HC, Tran HD, Illingworth GD, Krist JE, White RL, Sparks WB, Gronwall C, Cross NJG, Hartig GF, Clampin M, Ardila DR, Bartko F, Benitez N, Blakeslee JP, Bouwens RJ, Broadhurst TJ, Brown RA, Burrows CJ, Cheng ES, Feldman PD, Franx M, Golimowski DA, Infante L, Kimble RA, Lesser MP, McCann WJ, Menanteau F, Meurer GR, Miley GK, Postman M, ROSATI, Piero, Sirianni M, Tsvetanov ZI, Zheng W.   +34 more
openaire   +3 more sources

Disk Evolution Study Through Imaging of Nearby Young Stars (DESTINYS): Dynamical Evidence of a Spiral-Arm-Driving and Gap-Opening Protoplanet from SAO 206462 Spiral Motion

Universe
In the early stages of planetary system formation, young exoplanets gravitationally interact with their surrounding environments and leave observable signatures on protoplanetary disks.
Chen Xie, Chengyan Xie, Bin B. Ren, Myriam Benisty, Christian Ginski, Taotao Fang, Simon Casassus, Jaehan Bae, Stefano Facchini, François Ménard, Rob G. van Holstein   +10 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

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

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

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

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

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