Related papers: H-alpha features with hot onsets. II. A contrail f…
Even in quiet areas underneath coronal holes the solar chromosphere contains ubiquitous heating events. They tend to be small scale and short lived, hence difficult to identify. Here we do not address their much-debated contribution to…
In H-alpha most of the solar surface is covered by dense canopies of long opaque fibrils, but predictions for quiet-Sun observations with ALMA have ignored this fact. Comparison with Ly-alpha suggests that the large opacity of H-alpha…
Broad-band images of the solar chromosphere in the Ca II H&K line cores around active regions are covered with fine bright elongated structures called bright fibrils. The mechanisms that form these structures and cause them to appear bright…
Solar spicules are chromospheric fibrils that appear everywhere on the Sun, yet their origin is not understood. Using high resolution observations of spicules obtained with the Swedish 1-m Solar Telescope, we aim to understand how spicules…
Ellerman bombs are transient brightenings of the wings of the Balmer lines that uniquely mark reconnection in the solar photosphere. They are also bright in strong Ca II and ultraviolet lines and in ultraviolet continua, but they are not…
I have proposed that long Halpha fibrils are caused by heating events of which the tracks are afterwards outlined by contrails of cooling gas with extraordinary Halpha opacity and yet larger opacity at the ALMA wavelengths. Here I detail…
During the initial data reduction of the Wisconsin H-Alpha Mapper (WHAM) H-Alpha Sky Survey, we have discovered several very long (~30--80 deg) filaments superimposed on the diffuse H-Alpha background. These features have no clear…
Aim: To study the interaction of the solar chromosphere with the transition region, in particular active-region jets in the transition region and their relation to chromospheric fibrils. Methods: We carefully align image sequences taken…
We perform a multi-wavelength study of a two-ribbon flare on 2002 September 29 and its associated filament eruption, observed simultaneously in the H-alpha line by a ground-based imaging spectrograph and in hard X-rays by RHESSI. The flare…
Using the spectroscopic imaging capabilities of the Swedish Solar Telescope, we aim to provide the first investigation on the nature and dynamics of elongated absorption features (fibrils) observed in H$\alpha$ in the internetwork. We…
In this paper, we analyze the physical properties of dark mottles in the chromospheric network using two dimensional spectroscopic observations in H-alpha obtained with the Gottingen Fabry-Perot Spectrometer in the Vacuum Tower Telescope at…
Observations of the solar chromosphere in the line-core of the \Halpha\ line show dark elongated structures called fibrils that show swaying motion. We performed a 3D radiation-MHD simulation of a network region, and computed synthetic…
We present unprecedented high resolution H-alpha observations, obtained with the Swedish 1-m Solar Telescope, that, for the first time, spatially and temporally resolve dynamic fibrils in active regions on the Sun. These jet-like features…
The chromospheric H-alpha spectral line is a strong line in the spectrum of the Sun and other stars. In the stellar regime, this spectral line is already used as a powerful tracer of stellar activity. For the Sun, other tracers (i.e, CaII…
Type-II solar spicules appear as long, thin, highly dynamic strands of field-tied matter that feed significant mass and energy to the corona and solar wind. A recent result is that they exhibit torsional Alfv\'en waves in addition to…
We recently reported extremely rapid changes in chromospheric fine structure observed using the IBIS instrument in the red wing of H alpha. Here, we examine data obtained during the same observing run (August 7 2010), of a mature active…
Emission of solar flares across the electromagnetic spectrum is often observed in the form of two expanding ribbons. The standard flare model explains the flare ribbons as footpoints of magnetic arcades, emitting due to interaction of…
Radio and optical observations of the evolution of flare-associated phenomena have shown an initial and rapid burst at 0.4 THz only followed subsequently by a localized chromospheric heating producing an H{\alpha} brightening with later…
Chromospheric wave activity around flares and filaments has been a research focus for years, and could provide indirect measurements of local conditions that are not otherwise accessible. One interesting observed phenomenon is oscillations…
Over the last two decades the uninterrupted, high-resolution observations of the Sun, from the excellent range of telescopes aboard many spacecraft complemented with observations from sophisticated ground-based telescopes have opened up a…