Search Publications
On the three-dimensional configuration of coronal mass ejections
Bothmer, V.; Cremades, H.
Coronal mass ejections (CMEs) are a direct consequence of the dynamic nature of the solar atmosphere. They represent fundamental processes in which energy is transferred from the Sun into interplanetary space, including geospace. Their origin, 3D structure and internal magnetic field configuration are to date not well understood. The SOHO spacecra…
Emergence of magnetic flux from the convection zone into the corona
O'Shea, E.; Galsgaard, K.; Moreno-Insertis, F. +2 more
Numerical experiments of the emergence of magnetic flux from the uppermost layers of the solar interior to the photosphere and its further eruption into the low atmosphere and corona are carried out. We use idealized models for the initial stratification and magnetic field distribution below the photosphere similar to those used for multidimension…
Automated recognition of coronal mass ejections (CMEs) in near-real-time data
Berghmans, D.; Robbrecht, E.
This paper presents a new method and first applications of software that we have developed to autonomously detect CMEs in image sequences from LASCO (Large Angle Spectrometric Coronagraph). The crux of the software is the detection of CMEs as bright ridges in (time, height) maps using the Hough transform. The next step employs clustering and morph…
On the nature of EIT waves, EUV dimmings and their link to CMEs
Zhukov, A. N.; Auchère, F.
EIT waves and extreme-ultraviolet (EUV) dimmings attract particular attention as they frequently accompany Coronal Mass Ejections (CMEs). We present several examples of EIT waves and EUV dimmings with particular morphologies previously unreported in the literature. We report for the first time an EIT wave in the Fe XV (284 Å) bandpass of the SOHO/…
Synopsis of the interstellar He parameters from combined neutral gas, pickup ion and UV scattering observations and related consequences
Möbius, E.; Noda, H.; Bzowski, M. +17 more
A coordinated effort to combine all three methods that are used to determine the physical parameters of interstellar gas in the heliosphere has been undertaken. In order to arrive at a consistent parameter set that agrees with the observations of neutral gas, pickup ions and UV backscattering we have combined data sets from coordinated observation…
Magnetic Doppler imaging of 53 Camelopardalis in all four Stokes parameters
Petit, P.; Piskunov, N.; Wade, G. A. +5 more
We present the first investigation of the structure of the stellar surface magnetic field using line profiles in all four Stokes parameters. We extract the information about the magnetic field geometry and abundance distributions of the chemically peculiar star 53 Cam by modelling time-series of high-resolution spectropolarimetric observations wit…
A multiwavelength study of solar flare waves. I. Observations and basic properties
Magdalenić, J.; Vršnak, B.; Hanslmeier, A. +2 more
Propagating wave-like disturbances associated with solar flares - commonly observed in the chromosphere as Moreton waves - have been known for several decades. Recently, the phenomenon has come back into focus prompted by the observation of coronal waves with the SOHO/EIT instrument (``EIT waves"). It has been suggested that they represent the ant…
A multiwavelength study of solar flare waves. II. Perturbation characteristics and physical interpretation
Magdalenić, J.; Vršnak, B.; Hanslmeier, A. +2 more
The study of solar flare waves - globally propagating wave-like disturbances usually observed in Hα as Moreton waves - has recently come back into focus prompted by the observation of coronal waves in the EUV with the SOHO/EIT instrument (``EIT waves"), and in several additional wavelength channels. We study 12 flare wave events in order to determ…
Solar magnetic elements at 0.1 arcsec resolution. General appearance and magnetic structure
Hansteen, V. H.; Carlsson, M.; Berger, T. E. +6 more
New observations of solar magnetic elements in a remnant active region plage near disk center are presented. The observations were obtained at the recently commissioned Swedish 1-m Solar Telescope on La Palma. We examine a single 430.5 nm G-band filtergram that resolves ∼70 km (0.1 arcsec) structures and find new forms of magnetic structures in th…
Kinematics of coronal mass ejections between 2 and 30 solar radii. What can be learned about forces governing the eruption?
Vršnak, B.; Gopalswamy, N.; Sudar, D. +1 more
Kinematics of more than 5000 coronal mass ejections (CMEs) measured in the distance range 2-30 solar radii is investigated. A distinct anticorrelation between the acceleration, a, and the velocity, v, is found. In the linear form, it can be represented as a=-k1(v-v0), where v0=400 km s-1, i.e., most of C…