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Variability and Dynamics of the Outer Atmospheric Layers in the Quiet Solar Network
Curdt, W.; Rybák, J.; Gömöry, P. +2 more
A detailed study of the temporal evolution of the chromospheric He I 584.33 Å and the transition region O V 629.73 Å emission line intensities of quiet supergranular network of the Sun near disk centre observed with Coronal Diagnostic Spectrometer (CDS) is presented. A wavelet analysis of the 1729 s (28.8 min) long temporal series was performed in…
In-Situ Heating in Active Region Loops
Wang, T.; Curdt, W.; Landi, E. +1 more
We report new observational results and insights in the energy release during transient events on sub-flare level in active region coronal loops. Our work is based on multi-temperature observations obtained high above the limb by the SUMER spectrometer on SOHO. We conclude that the energy is impulsively injected into the loop system from one and o…
Characteristics of Active Galactic Nuclei in the Ultraviolet
Kautsch, S. J.; Zeilinger, W. W.
A sample of UV spectra of the central region of 28 early-type galaxies with signatures of nuclear activity is produced by collecting spectra from the on-line archive of the International Ultraviolet Explorer (IUE) satellite mission. We present a comparison of line flux measurements and the spectral energy distribution (SED) of these objects. The r…
Characteristics of Solar Type II Kilometer-Wave Radio Bursts
Hoang, S.; Zlobec, P.
In the spectral observations obtained at kilometric wavelengths by the instruments on Ulysses spacecraft solar low drift bursts were detected. Some of their characteristic parameters as well as similitudes and differences in respect to type II bursts observed at higher frequencies are considered.
Element Identifications in the UV Spectrum of HR 465
Fuhrmann, K.
High resolution IUE spectra of HR 465 were investigated. Line identifications for C, N, Eu, and Pt are presented, the occurrence of some other elements discussed.
Variable mass-flux in Be stars
Doazan, V.; Thomas, R. N.
The available observational data concerning the variability of Be stars is briefly reviewed, and some different hypotheses concerning the origin of Be variability are examined. It is shown that variability in Be stars is not restricted to short time scales. In fact, long term variations (such as 'E/C' variations of the intensity of the emission co…