Related papers: Coronal Magnetic Fields Derived from Simultaneous …

The opening-up of the magnetic field during solar eruptive events is often accompanied by a dimming of the local coronal emission. From observations of filament eruptions recorded with the Extreme-Ultraviolet Imager on STEREO during…

We estimate the energy input into the solar corona from photospheric footpoint motions, using observations of a plage region by the Hinode Solar Optical Telescope. Assuming a perfectly ideal coronal evolution, two alternative lower bounds…

Although the differential rotation rate on the solar surface has long been studied using optical and extreme ultraviolet (EUV) observations, associating these measurements to specific atmospheric heights remains challenging due to the…

Using data collected by the Indian Mars Orbiter Mission in October 2021, we investigated coronal regions of the Sun by analyzing the Doppler spectral width of radio signals to estimate solar wind velocity. A simplified equation is…

The Type-II solar radio burst recorded on 13 June 2010 by the radio spectrograph of the Hiraiso Solar Observatory was employed to estimate the magnetic-field strength in the solar corona. The burst was characterized by a well pronounced…

Small-scale propagating disturbances (PD) are ubiquitous in the solar corona. Time-Normalised Optical Flow (TNOF) is a method developed for mapping PD velocity fields in time series of Extreme-Ultraviolet (EUV) images. We show PD velocity…

Coronal loops are plasma structures in the solar atmosphere with temperatures reaching millions of Kelvin, shaped and sustained by the magnetic field. However, their morphology and fundamental nature remain subjects of debate. By studying…

Global magnetic field models use as input synoptic data, which usually show "aging effects" as the longitudinal 360{\deg} information is not obtained simultaneously. Especially during times of increased solar activity, the evolution of the…

Magnetic fields in the solar corona are responsible for a wide range of phenomena. However, any direct measurements of the coronal magnetic fields are very difficult due to lack of suitable spectral lines, weak magnetic fields, and high…

Metric radio bursts are often said to be valuable diagnostic tools for studying the near-sun kinematics and energetics of the Interplanetary Coronal Mass Ejections (ICMEs). Radio observations also serve as an indirect tool to estimate the…

Coronal mass ejections (CMEs) are large eruptions of plasma and magnetic field from the low solar corona into interplanetary space. These eruptions are often associated with the acceleration of energetic electrons which produce various…

At low coronal temperatures around or below 1 MK distinct areas in the surroundings of active regions (AR) show emission at a level significantly below the emission coming from the quiet Sun (QS). These areas are referred to as dark halos,…

A plethora of coronal models, from empirical to more complex magnetohydrodynamic (MHD) ones, are being used for reconstructing the coronal magnetic field topology and estimating the open magnetic flux. However, no individual solution fully…

The structure of the solar corona is dominated by the magnetic field because the magnetic pressure is about four orders of magnitude higher than the plasma pressure. Due to the high conductivity the emitting coronal plasma (visible e.g. in…

Radio-bright regions near the solar poles are frequently observed in Nobeyama Radioheliograph (NoRH) maps at 17 GHz, and often in association with coronal holes. However, the origin of these polar brightening has not been established yet.…

Images taken in the band centered at 30.4 nm are routinely used to map the radiance of the He II Ly alpha line on the solar disk. That line is one of the strongest, if not the strongest, line in the EUV observed in the solar spectrum, and…

Modern radio telescopes are extremely sensitive to plasma on the line of sight from a radio source to the antenna. Plasmas in the corona and solar wind produce measurable changes in the radio wave amplitude and phase, and the phase…

Understanding solar coronal magnetic fields is crucial to address the long-standing mysteries of the solar corona and solar wind. Although routine photospheric magnetic fields (MFs) are available for decades, coronal MFs are rarely…

The coronal magnetic field is an important quantity because the magnetic field dominates the structure of the solar corona. Unfortunately direct measurements of coronal magnetic fields are usually not available. The photospheric magnetic…

On 13 February 2009, a coronal wave -- CME -- dimming event was observed in quadrature by the STEREO spacecraft. We analyze this event using a three-dimensional, global magnetohydrodynamic (MHD) model for the solar corona. The numerical…