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Onboard Automated CME Detection Algorithm for the Visible Emission Line Coronagraph on ADITYA-L1
Pant, Vaibhav; Banerjee, Dipankar; Sankarasubramanian, K. +3 more
ADITYA-L1 is India's first space mission to study the Sun from the Lagrange 1 position. The Visible Emission Line Coronagraph (VELC) is one of seven payloads on the ADITYA-L1 mission, which is scheduled to be launched around 2020. One of the primary objectives of the VELC is to study the dynamics of coronal mass ejections (CMEs) in the inner coron…
The 2015 Summer Solstice Storm: One of the Major Geomagnetic Storms of Solar Cycle 24 Observed at Ground Level
Augusto, C. R. A.; Navia, C. E.; de Oliveira, M. N. +8 more
We report on the 22 - 23 June 2015 geomagnetic storm that occurred at the summer solstice. There have been fewer intense geomagnetic storms during the current solar cycle, Solar Cycle 24, than in the previous cycle. This situation changed after mid-June 2015, when one of the largest solar active regions (AR 12371) of Solar Cycle 24 that was locate…
Estimate of the Upper Limit on Hot Plasma Differential Emission Measure (DEM) in Non-Flaring Active Regions and Nanoflare Frequency Based on the Mg XII Spectroheliograph Data from CORONAS-F/SPIRIT
Reva, Anton; Ulyanov, Artem; Kirichenko, Alexey +2 more
Nanoflare-heating theory predicts steady hot-plasma emission in non-flaring active regions. It is hard to find this emission with conventional non-monochromatic imagers (such as the Atmospheric Imaging Assembly or the X-Ray Telescope), because their images contain a cool-temperature background. In this work, we search for hot plasma in non-flaring…
Dynamics of Trees of Fragmenting Granules in the Quiet Sun: Hinode/SOT Observations Compared to Numerical Simulation
Roudier, T.; Malherbe, J. -M.; Frank, Z. +1 more
We compare horizontal velocities, vertical magnetic fields, and the evolution of trees of fragmenting granules (TFG, also named families of granules) derived in the quiet Sun at disk center from observations at solar minimum and maximum of the Solar Optical Telescope (SOT on board Hinode) and results of a recent 3D numerical simulation of the magn…
On the Performance of Multi-Instrument Solar Flare Observations During Solar Cycle 24
Milligan, Ryan O.; Ireland, Jack
The current fleet of space-based solar observatories offers us a wealth of opportunities to study solar flares over a range of wavelengths. Significant advances in our understanding of flare physics often come from coordinated observations between multiple instruments. Consequently, considerable efforts have been, and continue to be, made to coord…
Visibility and Origin of Compact Interplanetary Radio Type IV Bursts
Pohjolainen, Silja; Talebpour Sheshvan, Nasrin
We have analyzed radio type IV bursts in the interplanetary (IP) space at decameter-hectometer (DH) wavelengths to determine their source origin and a reason for the observed directivity. We used radio dynamic spectra from the instruments on three different spacecraft, STEREO-A, Wind, and STEREO-B, which were located approximately 90 degrees apart…
An on Orbit Determination of Point Spread Functions for the Interface Region Imaging Spectrograph
De Pontieu, Bart; Kankelborg, Charles; Wülser, Jean-Pierre +1 more
Using the 2016 Mercury transit of the Sun, we characterize on orbit spatial point spread functions (PSFs) for the Near- (NUV) and Far- (FUV) Ultra-Violet spectrograph channels of NASA's Interface Region Imaging Spectrograph (IRIS). A semi-blind Richardson-Lucy deconvolution method is used to estimate PSFs for each channel. Corresponding estimates …
Deprojected Trajectory of Blobs in the Inner Corona
Blanco-Cano, X.; Panasenco, O.; Stenborg, G. +1 more
We have carried out a statistical analysis of the kinematical behavior of small white-light transients (blobs) as tracers of the slow solar wind. The characterization of these faint white-light structures gives us insight on the origin and acceleration of the slow solar wind. The vantage observing points provided by the SECCHI and LASCO instrument…
Turbulence and Heating in the Flank and Wake Regions of a Coronal Mass Ejection
He, Jiansen; Tian, Hui; Wang, Linghua +5 more
As a coronal mass ejection (CME) passes, the flank and wake regions are typically strongly disturbed. Various instruments, including the Large Angle and Spectroscopic Coronagraph (LASCO), the Atmospheric Imaging Assembly (AIA), and the Coronal Multi-channel Polarimeter (CoMP), observed a CME close to the east limb on 26 October 2013. A hot (≈10 MK…
Intense Geomagnetic Storms Associated with Coronal Holes Under the Weak Solar-Wind Conditions of Cycle 24
Watari, S.
The activity of Solar Cycle 24 has been extraordinarily low. The yearly averaged solar-wind speed is also lower in Cycle 24 than in Cycles 22 and 23. The yearly averaged speed in the rising phase of Cycle 21 is as low as that of Cycle 24, although the solar activity of Cycle 21 is higher than that of Cycle 24. The relationship between the solar-wi…