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Image Stabilization System for Hinode (Solar-B) Solar Optical Telescope
Ichimoto, K.; Kobayashi, K.; Tsuneta, S. +16 more
The Hinode Solar Optical Telescope (SOT) is the first space-borne visible-light telescope that enables us to observe magnetic-field dynamics in the solar lower atmosphere with 0.2 - 0.3 arcsec spatial resolution under extremely stable (seeing-free) conditions. To achieve precise measurements of the polarization with diffraction-limited images, sta…
Origin of Coronal Shock Waves. Invited Review
Vršnak, Bojan; Cliver, Edward W.
The basic idea of the paper is to present transparently and confront two different views on the origin of large-scale coronal shock waves, one favoring coronal mass ejections (CMEs), and the other one preferring flares. For this purpose, we first review the empirical aspects of the relationship between CMEs, flares, and shocks (as manifested by ra…
Nonlinear Force-Free Modeling of Coronal Magnetic Fields. II. Modeling a Filament Arcade and Simulated Chromospheric and Photospheric Vector Fields
Wiegelmann, Thomas; Schrijver, Carolus J.; Valori, Gherardo +6 more
We compare a variety of nonlinear force-free field (NLFFF) extrapolation algorithms, including optimization, magneto-frictional, and Grad - Rubin-like codes, applied to a solar-like reference model. The model used to test the algorithms includes realistic photospheric Lorentz forces and a complex field including a weakly twisted, right helical flu…
A New Model for Propagating Parts of EIT Waves: A Current Shell in a CME
Aulanier, G.; Török, T.; Hochedez, J. -F. +1 more
EIT waves are observed in EUV as bright fronts. Some of these bright fronts propagate across the solar disk. EIT waves are all associated with a flare and a CME and are commonly interpreted as fast-mode magnetosonic waves. Propagating EIT waves could also be the direct signature of the gradual opening of magnetic field lines during a CME. We quant…
Automatic Detection and Tracking of Coronal Mass Ejections in Coronagraph Time Series
Zhang, J.; Olmedo, O.; Poland, A. +2 more
We present the current capabilities of a software tool to automatically detect coronal mass ejections (CMEs) based on time series of coronagraph images: the solar eruptive event detection system (SEEDS). The software developed consists of several modules: preprocessing, detection, tracking, and event cataloging. The detection algorithm is based on…
The Hinode X-Ray Telescope (XRT): Camera Design, Performance and Operations
Weber, M.; Golub, L.; Kano, R. +15 more
The X-ray Telescope (XRT) aboard the Hinode satellite is a grazing incidence X-ray imager equipped with a 2048×2048 CCD. The XRT has 1 arcsec pixels with a wide field of view of 34×34 arcmin. It is sensitive to plasmas with a wide temperature range from < 1 to 30 MK, allowing us to obtain TRACE-like low-temperature images as well as Yohkoh/SXT-…
Radio Emission of Flares and Coronal Mass Ejections. Invited Review
Klein, K. -L.; Nindos, A.; Aurass, H. +1 more
We review recent progress on our understanding of radio emission from solar flares and coronal mass ejections (CMEs) with emphasis on those aspects of the subject that help us address questions about energy release and its properties, the configuration of flare - CME source regions, coronal shocks, particle acceleration and transport, and the orig…
An Extreme Solar Event of 20 January 2005: Properties of the Flare and the Origin of Energetic Particles
Kurt, V. G.; Grechnev, V. V.; Chertok, I. M. +9 more
The famous extreme solar and particle event of 20 January 2005 is analyzed from two perspectives. Firstly, using multi-spectral data, we study temporal, spectral, and spatial features of the main phase of the flare, when the strongest emissions from microwaves up to 200 MeV gamma-rays were observed. Secondly, we relate our results to a long-standi…
Helioseismology of Sunspots: Confronting Observations with Three-Dimensional MHD Simulations of Wave Propagation
Duvall, T. L., Jr.; Gizon, L.; Cameron, R.
The propagation of solar waves through the sunspot of AR 9787 is observed by using temporal cross-correlations of SOHO/MDI Dopplergrams. We then use three-dimensional MHD numerical simulations to compute the propagation of wave packets through self-similar magnetohydrostatic sunspot models. The simulations are set up in such a way as to allow a co…
First Imaging of Coronal Mass Ejections in the Heliosphere Viewed from Outside the Sun Earth Line
Howard, Russell A.; Bewsher, Danielle; Davis, Christopher J. +13 more
We show for the first time images of solar coronal mass ejections (CMEs) viewed using the Heliospheric Imager (HI) instrument aboard the NASA STEREO spacecraft. The HI instruments are wide-angle imaging systems designed to detect CMEs in the heliosphere, in particular, for the first time, observing the propagation of such events along the Sun - Ea…