Search Publications
The 2012 July 23 Backside Eruption: An Extreme Energetic Particle Event?
Gopalswamy, N.; Yashiro, S.; Mäkelä, P. +3 more
The backside coronal mass ejection (CME) of 2012 July 23 had a short Sun-to-Earth shock transit time (18.5 hr). The associated solar energetic particle (SEP) event had a >10 MeV proton flux peaking at ∼5000 pfu, and the energetic storm particle event was an order of magnitude larger, making it the most intense event in the space era at these en…
Quasi-periodic Pulsations during the Impulsive and Decay phases of an X-class Flare
Hayes, L. A.; Gallagher, P. T.; Dennis, B. R. +3 more
Quasi-periodic pulsations (QPPs) are often observed in X-ray emission from solar flares. To date, it is unclear what their physical origins are. Here, we present a multi-instrument investigation of the nature of QPP during the impulsive and decay phases of the X1.0 flare of 2013 October 28. We focus on the character of the fine structure pulsation…
Radio Diagnostics of Electron Acceleration Sites During the Eruption of a Flux Rope in the Solar Corona
Gallagher, Peter T.; Carley, Eoin P.; Vilmer, Nicole
Electron acceleration in the solar corona is often associated with flares and the eruption of twisted magnetic structures known as flux ropes. However, the locations and mechanisms of such particle acceleration during the flare and eruption are still subject to much investigation. Observing the exact sites of particle acceleration can help confirm…
Jets, Coronal “Puffs,” and a Slow Coronal Mass Ejection Caused by an Opposite-polarity Region within an Active Region Footpoint
Morgan, H.; Alzate, N.
During a period of three days beginning 2013 January 17, twelve recurrent reconnection events occur within a small region of opposing flux embedded within one footpoint of an active region, accompanied by flares and jets observed in EUV and fast and faint structureless “puffs” observed by coronagraphs. During the same period a slow structured CME …
The Blob Connection: Searching for Low Coronal Signatures of Solar Post-CME Blobs
Reeves, Katharine K.; Webb, David F.; Schanche, Nicole E.
Bright linear structures, thought to be indicators of a current sheet (CS), are often seen in Large Angle and Spectrometric Coronagraph (LASCO) on the Solar and Heliospheric Observatory (SOHO) white-light data in the wake of coronal mass ejections (CMEs). In a subset of these post-CME structures, relatively bright blobs are seen moving outward alo…
Redefining the Boundaries of Interplanetary Coronal Mass Ejections from Observations at the Ecliptic Plane
Guerrero, A.; Cid, C.; Saiz, E. +1 more
On 2015 January 6-7, an interplanetary coronal mass ejection (ICME) was observed at L1. This event, which can be associated with a weak and slow coronal mass ejection, allows us to discuss the differences between the boundaries of the magnetic cloud and the compositional boundaries. A fast stream from a solar coronal hole surrounding this ICME off…
On the Absence of EUV Emission from Comet C/2012 S1 (ISON)
Pesnell, W. Dean; Bryans, Paul
When the sungrazing comet C/2012 S1 (ISON) made its perihelion passage within two solar radii of the Sun’s surface, it was expected to be a bright emitter at extreme ultraviolet (EUV) wavelengths. However, despite solar EUV telescopes repointing to track the orbit of the comet, no emission was detected. This “null result” is interesting in its own…