Search Publications
X-ray sources and magnetic reconnection in the X3.9 flare of 2003 November 3
Magdalenić, J.; Temmer, M.; Veronig, A. M. +5 more
Context: .Recent RHESSI observations indicate an apparent altitude decrease of flare X-ray loop-top (LT) sources before changing to the commonly observed upward growth of the flare loop system.
Aims: .We performed a detailed study of the LT altitude decrease for one well observed flare in order to find further hints on the physics of this phen…
Reconstruction of solar irradiance variations in cycles 21-23 based on surface magnetic fields
Solanki, S. K.; Krivova, N. A.; Fröhlich, C. +1 more
Aims.We present a reconstruction of total solar irradiance (TSI) back to 1974, i.e. from the minimum of cycle 21 to the declining phase of cycle 23. We also present a cross-calibration between the magnetograms obtained by the 512 channel magnetograph and the spectromagnetograph at Kitt Peak.
Methods: .The TSI reconstruction is carried out usin…
Multi-wavelength study of coronal waves associated with the CME-flare event of 3 November 2003
Magdalenić, J.; Temmer, M.; Vršnak, B. +4 more
The large flare/CME event that occurred close to the west solar limb on 3 November 2003 launched a large-amplitude large-scale coronal wave that was observed in Hα and Fe xii 195 Å spectral lines, as well as in the soft X-ray and radio wavelength ranges. The wave also excited a complex decimeter-to-hectometer type II radio burst, revealing the for…
Charge-transfer induced EUV and soft X-ray emissions in the heliosphere
Lallement, R.; Izmodenov, V.; Quémerais, E. +4 more
Aims.We study the EUV/soft X-ray emission generated by charge transfer between solar wind heavy ions and interstellar neutral atoms and variations of the X-ray intensities and spectra with the line of sight direction, the observer location, the solar cycle phase and the solar wind anisotropies, and a temporary enhancement of the solar wind similar…
Large amplitude oscillation of a polar crown filament in the pre-eruption phase
Isobe, H.; Tripathi, D.
Aims.We report observation of a large-amplitude filament oscillation followed by an eruption. This is used to probe the pre-eruption condition and the trigger mechanism of solar eruptions.Methods.We used the EUV images from the Extreme-Ultraviolet Imaging Telescope on board SOHO satellite and the Hα images from the Flare Monitoring Telescope at Hi…
Evolution of magnetic fields and energetics of flares in active region 8210
Régnier, S.; Canfield, R. C.
To better understand eruptive events in the solar corona, we combine sequences of multi-wavelength observations and modelling of the coronal magnetic field of NOAA AR 8210, a highly flare-productive active region. From the photosphere to the corona, the observations give us information about the motion of magnetic elements (photospheric magnetogra…
On the propagation of brightening after filament/prominence eruptions, as seen by SoHO-EIT
Mason, H. E.; Isobe, H.; Tripathi, D.
Aims.To study the relationship between the propagation of brightening and erupting filaments/prominences in order to get some insight into the three-dimensional picture of magnetic reconnection.
Methods: .Analysis of the observations taken with the EIT (Extreme-ultraviolet Imaging Telescope) aboard SoHO (Solar and Heliospheric Observatory).
The early phases of a solar prominence eruption and associated flare: a multi-wavelength analysis
Mason, H. E.; Isobe, H.; Tripathi, D. +2 more
Aims.We aim to examine the precursor phases and early evolution of a prominence eruption associated with a M4-class flare and a partial halo coronal mass ejection (CME) observed on 2005 July 27. Our main goal is to investigate the precursor eruption signatures observed in EUV, X-ray and microwave emission and their relation to the prominence desta…
Solar coronal-hole plasma densities and temperatures
Wilhelm, K.
Polar plumes extending from the Sun into the solar corona have long been seen during eclipses, and can now be studied without this restriction with telescopes and spectrometers on board of spacecraft. Despite the large amount of observational data available on this prominent phenomenon, it is not clear whether plumes contribute substantially to th…
The timing of relativistic proton acceleration in the 20 January 2005 flare
Simnett, G. M.
Understanding the energy budget in large solar flares requires a good knowledge of how and where the energetic charged particles are accelerated. If they are mainly accelerated by a Coronal Mass Ejection (CME)-driven shock, then they do not have to derive their energy from the flare region. Conversely, if the CME does not accelerate the particles,…