Search Publications
Decomposing the AIA 304 Å Channel into Its Cool and Hot Components
Antolin, Patrick; Auchère, Frédéric; Soubrié, Elie +2 more
The AIA 304 Å channel on board the Solar Dynamics Observatory (SDO) offers a unique view of ≈105 K plasma emitting in the He II 304 Å line. However, when observing off-limb, the emission of the (small) cool structures in the solar atmosphere (such as spicules, coronal rain and prominence material) can be of the same order as the surrounding hot co…
Origin of the Chromospheric Umbral Waves in Sunspots
Xu, Zhe; Xue, Zhike; Yan, Xiaoli +5 more
Oscillations are ubiquitous in sunspots and the associated higher atmospheres. However, it is still unclear whether these oscillations are driven by the external acoustic waves (p-modes) or generated by the internal magnetoconvection. To obtain clues about the driving source of umbral waves in sunspots, we analyzed the spiral wave patterns (SWPs) …
IRIS Observational Approach to the Oscillatory and Damping Nature of Network and Internetwork Chromosphere Small-Scale Brightening (SSBs) and Their Unusual Dynamical and Morphological Differences in Different Regions on the Solar Disk
Tavabi, Ehsan; Sadeghi, Rayhaneh
One of the most exciting benefits of solar small-scale brightening is their oscillations. This study investigated the properties of small-scale brightening (SSBs) in different regions of the Sun and found that there are differences and similarities in the properties of oscillated and non-oscillated SSBs in different regions of the Sun, including q…
Explosive Events in the Quiet Sun Near and Beyond the Solar Limb Observed with the Interface Region Imaging Spectrograph (IRIS)
Vial, J. -C.; Alissandrakis, C. E.
We study point-like explosive events (EE), characterized by emission in the far wings of spectral lines, in a quiet region near the South Pole, using Interface Region Imaging Spectrograph (IRIS) spectra at two slit positions, slit-jaw (SJ) observations, and Atmospheric Imaging Assembly (AIA) images. The events were best visible in Si IV spectra; t…
The Solar Ultra-Violet Imaging Telescope (SUIT) Onboard Intelligence for Flare Observations
Tripathi, Durgesh; Tyagi, Anurag; Sankarasubramanian, K. +14 more
Aditya-L1 is India's first observatory-class solar space mission to study the Sun from the Lagrange L1 point. The Solar Ultra-Violet Imaging Telescope (SUIT) is one of the payloads onboard Aditya-L1. SUIT is an off-axis Ritchey-Chrétien (RC) telescope, which images the Sun onto a 4k×4k CCD covering a field-of-view of 1.5 R⊙ w…
Small-Scale Upflows in a Coronal Hole - Tracked from the Photosphere to the Corona
Barczynski, Krzysztof; Orozco Suárez, David; Mandrini, Cristina H. +4 more
Coronal transients are known as sources of coronal upflows. With the commissioning of Solar Orbiter, it became apparent that coronal small-scale features are even more frequent than previously estimated. It was found that even small coronal features seen by Solar Orbiter can produce visible upflows. Therefore, it is important to study the plasma f…
Invited Review: Short-term Variability with the Observations from the Helioseismic and Magnetic Imager (HMI) Onboard the Solar Dynamics Observatory (SDO): Insights into Flare Magnetism
Kazachenko, Maria D.; Welsch, Brian T.; Albelo-Corchado, Marcel F. +1 more
Continuous vector magnetic-field measurements by the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO) allow us to study magnetic-field properties of many flares. Here, we review new observational aspects of flare magnetism described using SDO data, including statistical properties of magnetic-reconnection fluxes …
Analysis of the Evolution of a Multi-Ribbon Flare and Failed Filament Eruption
Schmieder, Brigitte; Joshi, Reetika; Chandra, Ramesh +5 more
How filaments form and erupt are topics about which solar researchers have wondered for more than a century and they are still open to debate. We present observations of a filament formation, its failed eruption, and the associated flare (SOL2019-05-09T05:51) that occurred in active region (AR) 12740 using data from the Solar Dynamics Observatory …
Polarization Accuracy Verification of the Chromospheric LAyer SpectroPolarimeter
Hara, Hirohisa; De Pontieu, Bart; Carlsson, Mats +25 more
We have developed an advanced UV spectropolarimeter called Chromospheric LAyer SpectroPolarimeter (CLASP2), aimed at achieving very high accuracy measurements (<0.1% at 3 σ ) of the linear (Q /I and U /I ) and circular (V /I ) polarizations of the Mg II h and k lines (280 nm). CLASP2 was launched on board a NASA sounding rocket on April 11, 201…
On the Evolution of a Sub-C Class Flare: A Showcase for the Capabilities of the Revamped Catania Solar Telescope
Spadaro, Daniele; Guglielmino, Salvo L.; Romano, Paolo +9 more
Solar flares are occasionally responsible for severe space-weather events, which can affect space-borne and ground-based infrastructures, endangering anthropic technological activities and even human health and safety. Thus, an essential activity in the framework of space-weather monitoring is devoted to the observation of the activity level on th…