Related papers: Revision of Solar Spicule Classification
We characterize, for the first time, type-II spicules in Ca II K 3934\AA\ using the CHROMIS instrument at the Swedish 1-m Solar Telescope. We find that their line formation is dominated by opacity shifts with the K$_{3}$ minimum best…
The lifetimes and length-scales for supergranular cells in active and quiescent regions of the Solar chromosphere, and the relation between the two, were studied using a time series of Ca II K filtergrams. The lifetimes, in contrast to…
Rotation is a significant characteristic of the Sun and other stars, and it plays an important role in understanding their dynamo actions and magnetic activities. In this study, the rotation of the solar chromospheric activity is…
We analyze the time series of CaII H-line obtained from Hinode/SOT on the solar limb. The time-distance analysis shows that the axis of spicule undergos quasi-periodic transverse displacement at different heights from the photosphere. The…
We investigate high resolution spectroscopic and imaging observations from the CRisp Imaging SpectroPolarimeter (CRISP) instrument to study the dynamics of chromospheric spicule type events. It is widely accepted that chromospheric fine…
Height series of Doppler observation at the solar limb (covering 3800 - 8700 km distance above the photosphere) in $H_{\alpha}$ spectral line obtained by big coronagraph of Abastumani Astrophysical Observatory \citep{khu} show the periodic…
Coronal holes (CH) emit significantly less at coronal temperatures than quiet-Sun regions (QS), but can hardly be distinguished in most chromospheric and lower transition region lines. A key quantity for the understanding of this phenomenon…
The Sun has a steady 11-year cycle in magnetic activity most well-known by the rising and falling in the occurrence of dark sunspots on the solar disk in visible bandpasses. The 11-year cycle is also manifest in the variations of emission…
The relationship between observed structures in the solar atmosphere and the magnetic fields threading them is known only for the solar photosphere, even then imprecisely. We suggest that some of the fine structure in the more tenuous…
Broad-band images in the Ca II H line, from the BFI instrument on the Hinode spacecraft, show emission from spicules emerging from and visible right down to the observed limb. Surprisingly, little absorption of spicule light is seen along…
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…
Context. The Sun and solar-like stars undergo activity cycles for which the underlying mechanisms are not well understood. The oscillations of the Sun are known to vary with its activity cycle and these changes provide diagnostics on the…
Aims. With the Solar Optical Telescope on Hinode, we investigate the basic properties of high-degree solar oscillations observed at two levels in the solar atmosphere, in the G-band (formed in the photosphere) and in the Ca II H line…
Waves are an integral part of the solar atmosphere, and their characteristics (e.g., dominant period, range of periods, power, and phase angle) change on a diverse spatio-temporal scale. It is well well-established observationally that the…
We study a solar spicule observed off-limb using high-resolution imaging spectroscopy in the Ca II 8542 \AA\ line obtained with the CRisp Imaging SpectroPolarimeter (CRISP) on the Swedish 1-m Solar Telescope. Using a new version of the…
Light curves of solar-type stars often show gradual fluctuations due to rotational modulation by magnetic features (starspots and faculae) on stellar surfaces. Two quantitative measures of modulated light curves are employed as the proxies…
An attractive diagnostic tool for investigating the magnetism of the solar chromosphere is the observation and theoretical modeling of the Hanle and Zeeman effects in spicules, as shown in this letter for the first time. Here we report on…
Determining the magnetic field related to solar spicules is vital for developing adequate models of these plasma jets, which are thought to play a key role in the thermal, dynamic and magnetic structure of the Chromosphere. Here we report…
The convectively driven, weakly magnetized regions of the solar photosphere dominate the Sun's surface at any given time, but the temporal variations of these quiet regions of the photosphere throughout the solar cycle are still not well…
Spicules are among the most ubiquitous small-scale, jet-like features in the solar chromosphere and are widely believed to play a significant role in transporting mass and energy into the solar corona with their mechanisms not fully…