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Related papers: Combining White Light and UV Lyman-alpha Coronagra…

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Coronal Mass Ejections (CMEs) often show different features in different band-passes. By combining data in white-light (WL) and ultraviolet (UV) bands, we have applied different techniques to derive plasma temperatures, electron density,…

Solar and Stellar Astrophysics · Physics 2020-08-19 Beili Ying , Alessandro Bemporad , Li Feng , Lei Lu , Weiqun Gan , Hui Li

Understanding the physical processes responsible for accelerating the solar wind requires detailed measurements of the collisionless plasma in the extended solar corona. Some key clues about these processes have come from instruments that…

We present a method to derive outflow velocities in the solar corona using different data sets including solar wind mass flux coming from the SWAN/SOHO instrument, electron density values from LASCO-C2 and interplanetary solar wind…

Astrophysics · Physics 2009-11-13 E. Quemerais , R. Lallement , D. Koutroumpa , P. Lamy

We suggest a method that evaluates the horizontal velocity in the solar photosphere with easily observable values using a combination of neural network and radiative magnetohydrodynamics simulations. All three-component velocities of…

Solar and Stellar Astrophysics · Physics 2023-09-06 Hiroyuki Masaki , Hideyuki Hotta , Yukio Katsukawa , Ryohtaroh T. Ishikawa

Ultraviolet spectroscopy of the extended solar corona is a powerful tool for measuring the properties of protons, electrons, and heavy ions in the accelerating solar wind. The large coronal holes that expand up from the north and south…

Solar and Stellar Astrophysics · Physics 2020-07-28 Steven R. Cranmer

High contrast coronagraphic imaging of the immediate surrounding of stars requires exquisite control of low-order wavefront aberrations, such as tip-tilt (pointing) and focus. We propose an accurate, efficient and easy to implement…

Instrumentation and Methods for Astrophysics · Physics 2011-02-11 Olivier Guyon , Taro Matsuo , Roger Angel

When inverting solar spectra, image degradation effects that are present in the data are usually approximated or not considered. We develop a data reduction method that takes these issues into account and minimizes the resulting errors. By…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 M. van Noort

High throughput, low inner working angle (IWA) phase masks coronagraphs are essential to directly image and characterize (via spectroscopy) earth-like planets. However, the performance of low-IWA coronagraphs is limited by residual pointing…

Instrumentation and Methods for Astrophysics · Physics 2015-06-22 Garima Singh , Olivier Guyon , Pierre Baudoz , Nemanja Jovanovic , Frantz Martinache , Tomoyuki Kudo , Eugene Serabyn , Jonas G Kuhn

The hydrogen \lya\ line and the white-light (WL) continuum are two key diagnostics of energy transport in the lower atmosphere during solar flares, yet their relationship remains poorly understood. Here we present a statistical analysis of…

Solar and Stellar Astrophysics · Physics 2026-03-25 De-Chao Song , Ying Li , Qiao Li , Xiaofeng Liu

Emanating from the base of the Sun's corona, the solar wind fills the interplanetary medium with a magnetized stream of charged particles whose interaction with the Earth's magnetosphere has space-weather consequences such as geomagnetic…

Solar and Stellar Astrophysics · Physics 2020-06-11 Vishal Upendran , M. C. M Cheung , Shravan Hanasoge , Ganapathi Krishnamurthi

Accurate forecasting of the solar wind has grown in importance as society becomes increasingly dependent on technology that is susceptible to space weather events. This work describes an inner boundary condition for ambient solar wind…

Space Physics · Physics 2022-07-22 Kaine A. Bunting , Huw Morgan

We summarize the unique capabilities of UV coronagraphic spectroscopy for determining the detailed plasma properties (e.g., density, temperature, outflow speed, composition) of the source regions of both transient phenomena such as CMEs,…

Non-common path quasi-static and differential aberrations are one of the big hurdles of direct imaging for current and future high-contrast imaging instruments. They increase speckle and photon noise thus reducing the achievable contrast…

Instrumentation and Methods for Astrophysics · Physics 2024-07-22 Gilles Orban de Xivry , Olivier Absil , Christian Delacroix , Prashant Pathak , Maxime Quesnel , Thomas Bertram

The Earth's turbulent atmosphere results in speckled and blurred images of astronomical objects when observed by ground based visible and near-infrared telescopes. Adaptive optics (AO) systems are employed to reduce these atmospheric…

Instrumentation and Methods for Astrophysics · Physics 2022-11-30 Daniel M. Levinstein , Saavidra Perera , Quinn M. Konopacky , Alex Madurowicz , Bruce Macintosh , Lisa Poyneer , Richard W. Wilson

Focal plane wavefront sensing and control is a critical approach to reducing non-common path errors between the a conventional astronomical adaptive optics (AO) wavefront sensor (WFS) detector and science camera. However, in addition to…

Instrumentation and Methods for Astrophysics · Physics 2023-03-01 Benjamin L. Gerard , Daren Dillon , Sylvain Cetre , Rebecca Jensen-Clem

We present a new correlation method for deriving the F-corona intensity distribution, which is based on the analysis of the evolution of the total and polarized visible light (VL) images. We studied the one-month variation profiles of the…

Solar and Stellar Astrophysics · Physics 2022-03-14 A. Burtovoi , G. Naletto , S. Dolei , D. Spadaro , M. Romoli , F. Landini , Y. De Leo

Both remote-sensing measurements using the interplanetary scintillation (IPS) technique and in situ measurements by the Ulysses spacecraft show a bimodal structure for the solar wind at solar minimum conditions. At present what makes the…

Solar and Stellar Astrophysics · Physics 2015-05-27 Bo Li , Li-Dong Xia , Yao Chen

We present in this Letter the first coordinated radio occultation measurements and ultraviolet observations of the inner corona below 5.5 Rs, obtained during the Galileo solar conjunction in January 1997, to establish the origin of the slow…

Astrophysics · Physics 2009-10-30 S. R. Habbal , R. Woo , S. Fineschi , R. O'Neal , J. Kohl , G. Noci , C. Korendyke

Extreme UltraViolet images of the corona contain information over a large range of spatial scales, and different structures such as active regions, quiet Sun and filament channels contain information at very different brightness regimes.…

Solar and Stellar Astrophysics · Physics 2015-06-19 Huw Morgan , Miloslav Druckmuller
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