Search Publications
The Interstellar H Flow: Updated Analysis of SOHO/SWAN Data
Bertaux, Jean-Loup; Lallement, Rosine; Lamy, Philippe +4 more
We update two kinds of results obtained with the SWAN instrument on board SOHO. First, we use H cell data recorded in 2001 and derive the H flow direction in the same way the study was done at solar minimum. We again compare with the Helium flow direction and doing so correct for the coordinate system change between the Ulysses and SOHO missions. …
Tracking Nonradial Motions and Azimuthal Expansions of Interplanetary CMEs with the Solar Mass Ejection Imager
Webb, David; Kahler, Stephen
The trajectories of interplanetary CMEs (ICMEs) are modified by their interactions with solar wind streams. These interactions can result in non-radial deflections of ICME trajectories and changes to their rates of azimuthal expansion. The Solar Mass Ejection Imager (SMEI), launched earlier in 2003 January, has provided heliospheric images of seve…
SOHO/UVCS Detection of Turbulence in a Coronal Mass Ejection
Antonucci, E.; D'Amicis, R.; Telloni, D.
The intensity of the H I Lyα line measured by the UltraViolet Coronagraph Spectrometer (UVCS) onboard the Solar and Heliospheric Observatory (SOHO) is used to investigate the density turbulence within the coronal mass ejection (CME) occurred on 2006 December 24, in the South polar coronal hole. In order to compare the spectral index inside the CME…
Coronal Fine Linear Rays: Are They Fast Streams From Active Regions?
Golub, Leon; Filippov, Boris; Lamy, Philippe +3 more
Eclipse observations of the W-L corona show linear rays above active regions at times of solar maximum. We show that these linear rays are also observed in the field-of-view of the C2-LASCO coronagraph, in perfect correspondence with the eclipse results. A selected prominent case taken from the 2001 eclipse observation in Angola is analysed with s…
A CME-ICME study using data from SOHO and Ulysses
Dumitrache, Cristiana; Popescu, Nedelia A.; Oncica, Adrian
We analyze the solar source of a CME occurred on 2 March 2002, the follow up of its travel through the interplanetary space and the characteristics of the ICME registered by Ulysses satellite.
On The Possible Mechanism Of Energy Dissipation In Shock-Wave Fronts Driven Ahead Of Coronal Mass Ejections
Eselevich, M. V.; Eselevich, V. G.
Analysis of Mark 4 and LASCO C2, C3 coronagraph data shows that, at the distance R<=0 Rsolar from the center of the Sun, the thickness of a CME-generated shock-wave front (δF) may be of order of the proton mean free path. This means that the energy dissipation mechanism in the shock front at these distances is collisional.…
SOHO/ACE observations of two consecutive CMEs from the same source region
Romoli, M.; Mandrini, C. H.; Dasso, S. +2 more
On June 2, 2003, SOHO/LASCO coronagraph observed two CMEs at the West limb of the Sun, at 00.30 and 08:54 UT, respectively, which appeared to originate from the same source region. Both CMEs show the typical three-part structure. These events have been also observed by SOHO/UVCS, allowing us to infer their physical parameters. We also looked for i…
Observations of the 3D coronal structure over a solar cycle
Morgan, Huw; Habbal, Shadia
Solar rotational tomography is applied to almost eleven years of LASCO C2/SOHO data, revealing for the first time the structural behavior of streamers over almost a full solar activity cycle. Streamers are most often shaped as extended, narrow plasma sheets. The sheets can be extremely narrow at times (<=0.14×106 km at 4Rsolar