Search Publications
Space weather: the solar perspective: An update to Schwenn (2006)
Temmer, Manuela
The Sun, as an active star, is the driver of energetic phenomena that structure interplanetary space and affect planetary atmospheres. The effects of Space Weather on Earth and the solar system is of increasing importance as human spaceflight is preparing for lunar and Mars missions. This review is focusing on the solar perspective of the Space We…
Turbulent Generation of Magnetic Switchbacks in the Alfvénic Solar Wind
Cranmer, Steven R.; Shoda, Munehito; Chandran, Benjamin D. G.
One of the most important early results from the Parker Solar Probe (PSP) is the ubiquitous presence of magnetic switchbacks, whose origin is under debate. Using a three-dimensional direct numerical simulation of the equations of compressible magnetohydrodynamics from the corona to 40 solar radii, we investigate whether magnetic switchbacks emerge…
Coronal Hole Detection and Open Magnetic Flux
Temmer, Manuela; Vršnak, Bojan; Pinto, Rui F. +14 more
Many scientists use coronal hole (CH) detections to infer open magnetic flux. Detection techniques differ in the areas that they assign as open, and may obtain different values for the open magnetic flux. We characterize the uncertainties of these methods, by applying six different detection methods to deduce the area and open flux of a near-disk …
Detection of Flare Multiperiodic Pulsations in Mid-ultraviolet Balmer Continuum, Lyα, Hard X-Ray, and Radio Emissions Simultaneously
Li, Gang; Gan, Weiqun; Li, Xiaobo +7 more
Quasi-periodic pulsations (QPPs), which usually appear as temporal pulsations of the total flux, are frequently detected in the light curves of solar/stellar flares. In this study, we present the investigation of nonstationary QPPs with multiple periods during the impulsive phase of a powerful flare on 2017 September 6, which were simultaneously m…
A Model for the Coupled Eruption of a Pseudostreamer and Helmet Streamer
Lynch, B. J.; Antiochos, S. K.; Kumar, P. +3 more
A highly important aspect of solar activity is the coupling between eruptions and the surrounding coronal magnetic field topology, which determines the trajectory and morphology of the event and can even lead to sympathetic eruptions from multiple sources. In this paper, we report on a numerical simulation of a new type of coupled eruption, in whi…
Investigating Remote-sensing Techniques to Reveal Stealth Coronal Mass Ejections
Nitta, Nariaki V.; Richardson, Ian G.; Srivastava, Nandita +7 more
Eruptions of coronal mass ejections (CMEs) from the Sun are usually associated with a number of signatures that can be identified in solar disc imagery. However, there are cases in which a CME that is well observed in coronagraph data is missing a clear low-coronal counterpart. These events have received attention during recent years, mainly as a …
Analytical Framework for Space Debris Collision Avoidance Maneuver Design
Di Lizia, Pierluigi; Colombo, Camilla; Gonzalo, Juan Luis
An analytical formulation for collision avoidance maneuvers involving a spacecraft and a space debris is presented, including solutions for the maximum deviation and minimum collision probability cases. Gauss' planetary equations and relative motion equations are used to map maneuvers at a given time to displacements at the predicted close approac…
LOFAR Observations of a Jet-driven Piston Shock in the Low Solar Corona
Gallagher, Peter T.; Zucca, Pietro; Carley, Eoin P. +2 more
The Sun produces highly dynamic and eruptive events that can drive shocks through the corona. These shocks can accelerate electrons, which result in plasma emission in the form of a type II radio burst. Despite the large number of type II radio burst observations, the precise origin of coronal shocks is still subject to investigation. Here, we pre…
Automated Detection of Accelerating Solar Eruptions Using Parabolic Hough Transform
West, Matthew J.; Mierla, Marilena; Pant, Vaibhav +3 more
Solar eruptions such as coronal mass ejections (CMEs) observed in the inner solar corona (up to 4 R⊙) show acceleration profiles that appear as parabolic ridges in height-time plots. Inspired by the white-light automated detection algorithms Computer Aided CME Tracking System (CACTus) and Solar Eruptive Events Detection System (SEEDS), …
Radio evidence for a shock wave reflected by a coronal hole
Bemporad, A.; Frassati, F.; Giordano, S. +4 more
We report the first unambiguous observational evidence in the radio range of the reflection of a coronal shock wave at the boundary of a coronal hole. The event occurred above an active region located at the northwest limb of the Sun and was characterized by an eruptive prominence and an extreme-ultraviolet wave steepening into a shock. The EUV ob…