Related papers: Observing the Solar Chromosphere
A three-dimensional picture of the solar atmosphere's thermodynamics can be obtained by jointly analyzing multiple spectral lines that span many formation heights. In paper I, we found strong correlations between spectral shapes from a…
Small flares frequently occur in the quiet Sun. Previous studies have noted that they share many common characteristics with typical solar flares in active regions. However, their similarities and differences are not fully understood,…
Chromospheric plages are distributed between mid-latitude and the Equator and never close to the Poles. Therefore, we suspect that the inclination angle of the solar rotation axis has an impact on the observable chromospheric emission. We…
I argue that one should attempt to understand the solar chromosphere not only for its own sake, but also if one is interested in the physics of: the corona; astrophysical dynamos; space weather; partially ionized plasmas; heliospheric UV…
The heating and structure of the solar chromosphere depends on the underlying magnetic field, among other parameters. The lowest magnetic flux of the solar atmosphere is found in the quiet Sun internetwork and is thought to be provided by…
The solar atmosphere was traditionally represented with a simple one-dimensional model. Over the past few decades, this paradigm shifted for the chromosphere and corona that constitute the outer atmosphere, which is now considered a dynamic…
A tomographic method is described that makes it possible to follow the propagation of shock waves across the photosphere of long-period variable stars. The method relies on the correlation of the observed spectrum with numerical masks…
The complex spectropolarimetric patterns around strong chromospheric lines, the result of subtle spectroscopic and transport mechanisms, are sensitive, sometimes in unexpected ways, to the presence of magnetic fields in the chromosphere,…
Over the course of its motion through the Galaxy, our solar system has encountered many interstellar environments of varying characteristics. Interstellar medium (ISM) density variations spanning seven orders of magnitude are commonly seen…
The solar spectrum conveys most of our diagnostics to find out how our star works. They must be understood for utilization, but solar spectrum formation is complex because the interaction of matter and radiation within the solar atmosphere…
Three-dimensional numerical simulations with CO5BOLD, a new radiation hydrodynamics code, result in a dynamic, thermally bifurcated model of the non-magnetic chromosphere of the quiet Sun. The 3-D model includes the middle and low…
Chromospheric swirls are the observational signatures of rotating magnetic field structures in the solar atmosphere, also known as magnetic tornadoes. Swirls appear as dark rotating features in the core of the spectral line of singly…
Since the Lalpha rocket observations of (Gabriel, Solar Phys. 21, 392, 1971), it has been realized that the hydrogen (H) lines could be observed in the corona and offer an interesting diagnostic for the temperature, density, and radial…
There is growing observational evidence for some kind of interaction between stars and close-in extrasolar giant planets. Shkolnik et al. reported variability in the chromospheric Ca H and K lines of HD 179949 and upsilon And that seemed to…
Due to the continuous developments in polarimetric instrumentation, which will become even more dramatic in the near future with the availability of new generation solar telescopes, we are now severely confronted with a variety of new…
Oscillations of coronal loops in the Sun have been reported in both imaging and spectral observations at the onset of flares. Images reveal transverse oscillations, whereas spectra detect line-of-sight velocity or Doppler-shift…
Dark areas around active regions (ARs) have been first observed in chromospheric lines more than a century ago and are now associated to the H{\alpha} fibril vortex around ARs. Nowadays, large areas surrounding ARs with reduced emission…
Stepwise changes of the photospheric magnetic field, which often becomes more horizontal, have been observed during many flares. Previous interpretations include coronal loops that contract and it has been speculated that such jerks could…
Plage regions are patches of concentrated magnetic field in the Sun's atmosphere where hot coronal loops are rooted. While previous studies have shed light on the properties of plage magnetic fields in the photosphere, there are still…
The corona is a layer of hot plasma that surrounds the Sun, traces out its complex magnetic field, and ultimately expands into interplanetary space as the supersonic solar wind. Although much has been learned in recent decades from advances…