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Three Criteria to Discriminate between Elementary and Composite Coronal Loops
Aschwanden, Markus J.
In this Letter, we establish three simple criteria to discriminate between elementary and composite loop structures, based on observations from high-resolution (TRACE) and low-resolution (EIT) imagers. Both data sets contain triple-filter data with a temperature diagnostic in the range of T~0.7-2.8 MK, which we use for forward-fitting of a differe…
Resolving the enigmatic solar wind disappearance event of 11 May 1999
Janardhan, P.; Tokumaru, M.; Kojima, M. +2 more
On 11 and 12 May 1999, the Earth was engulfed by an unusually low-density (<1 cm-3) and low-velocity (<350 km s-1) solar wind for a period of over 1 day. Extensive studies of this unusual event that occurred during Carrington rotation 1949 (CR1949), using both ground-based and space-based in situ observations, have not …
Stability of the inner source pickup ions over the solar cycle
Geiss, J.; McComas, D. J.; Schwadron, N. A. +2 more
Inner source pickup ions (PUIs) were discovered and are observed by Ulysses. They are thought to be generated by solar wind interaction with dust grains near the Sun. From previous work, four constraints were derived on inner source PUIs from observations near solar minimum: (1) the composition resembles the solar wind; (2) the distribution functi…
Multipoint observations of transient reconnection signatures in the cusp precipitation: A Cluster-IMAGE detailed case study
Budnik, E.; Berchem, J.; Escoubet, C. P. +10 more
This paper uses 90 min of Cluster multipoint data at ∼5 RE altitude together with global dayside imaging data provided by the IMAGE-SI-12 instrument to analyze the northern cusp crossed on 14 July 2001, during a period of high solar wind pressure Psw and strongly duskward interplanetary magnetic field (IMF). Simultaneous obse…
Global structure of the out-of-ecliptic solar wind
Burlaga, L. F.; Sheeley, N. R.; Wang, Y. -M. +1 more
We use the observed photospheric field maps and the wind speed observed from Ulysses to study the out-of-ecliptic solar wind. The model calculates the wind speed from the rate of magnetic flux tube expansion factors using a conversion function that is determined by least squares fit of all currently available data from Ulysses. Using the best fit …
FUSE Observations of DB White Dwarfs
Kruk, J. W.; Chayer, P.; Petitclerc, N. +2 more
We present a comprehensive analysis of the far-ultraviolet spectra of three DB white dwarfs secured with the FUSE observatory. Transitions associated with various carbon ions are detected in all three objects. Atmospheric parameters are first redetermined on the basis of an analysis of archival data available, and the abundance of carbon, together…
Very long period activity at the base of solar wind streams
Doyle, J. G.; Xia, L. D.; Banerjee, D. +2 more
Using time series data of spectral lines originating from a wide range of temperatures in the solar transition region, above a polar coronal hole, from SUMER (Solar Ultraviolet Measurements of Emitted Radiation) on SoHO (Solar and Heliospheric Observatory), we report on the detection of very long (≈170 min) periodic intensity fluctuations, above t…
The Chemical Composition and Equation of State of the Sun Inferred from Seismic Models through an Inversion Procedure
Lin, Chia-Hsien; Däppen, Werner
The remarkable quality of present helioseismic data provides the possibility to investigate the microscopic physics of the solar interior. An inversion procedure to reveal the equation of state and chemical composition in the Sun has been developed. The method is based on using the discrepancy in the adiabatic gradient γ1≡(∂lnP/∂lnρ)
Millisecond radio spikes in the decimetre band and their related active solar phenomena
Siarkowski, M.; Falewicz, R.; Rudawy, P. +2 more
We present here a brief description of thirteen events of the narrowband solar millisecond radio spike emissions observed between February 2000 and December 2001. The total observing time was 1990.4 h, collected during the 357 observing days. The data were collected with the 15-m radio telescope and fast radiospectrograph of Toruń Observatory, Pol…
SMART-1: Development and lessons learnt
Rathsman, Peter; Kugelberg, Joakim; Bodin, Per +3 more
SMART-1 is the first of the small missions for advanced research and technology as part of ESA's science programme “Cosmic vision”. It was successfully launched on September 27, 2003 and is presently traveling towards its destination, the Moon. The main objective of the mission, to demonstrate solar electric primary propulsion for future Cornersto…