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Multi-Scale Gaussian Normalization for Solar Image Processing
DOI: 10.1007/s11207-014-0523-9 Bibcode: 2014SoPh..289.2945M

Morgan, Huw; Druckmüller, Miloslav

Extreme ultra-violet images of the corona contain information over a wide range of spatial scales, and different structures such as active regions, quiet Sun, and filament channels contain information at very different brightness regimes. Processing of these images is important to reveal information, often hidden within the data, without introduci…

2014 Solar Physics
PROBA-2 SOHO 180
The SPoCA-suite: Software for extraction, characterization, and tracking of active regions and coronal holes on EUV images
DOI: 10.1051/0004-6361/201321243 Bibcode: 2014A&A...561A..29V

Verbeeck, C.; Delouille, V.; Mampaey, B. +1 more

Context. Precise localization and characterization of active regions (AR) and coronal holes (CH) as observed by extreme ultra violet (EUV) imagers are crucial for a wide range of solar and helio-physics studies.
Aims: We introduce a set of segmentation procedures (known as the SPoCA-suite) that allows one to retrieve AR and CH properties on E…

2014 Astronomy and Astrophysics
PROBA-2 97
Asymmetry in the CME-CME Interaction Process for the Events from 2011 February 14-15
DOI: 10.1088/0004-637X/785/2/85 Bibcode: 2014ApJ...785...85T

Temmer, M.; Veronig, A. M.; Vršnak, B. +1 more

We present a detailed study of the interaction process of two coronal mass ejections (CMEs) successively launched on 2011 February 14 (CME1) and 2011 February 15 (CME2). Reconstructing the three-dimensional shape and evolution of the flux ropes, we verify that the two CMEs interact. The frontal structure of both CMEs, measured along different posi…

2014 The Astrophysical Journal
PROBA-2 SOHO 78
Observational Evidence of Torus Instability as Trigger Mechanism for Coronal Mass Ejections: The 2011 August 4 Filament Eruption
DOI: 10.1088/0004-637X/785/2/88 Bibcode: 2014ApJ...785...88Z

Mierla, M.; Seaton, D. B.; Poedts, S. +4 more

Solar filaments are magnetic structures often observed in the solar atmosphere and consist of plasma that is cooler and denser than their surroundings. They are visible for days—even weeks—which suggests that they are often in equilibrium with their environment before disappearing or erupting. Several eruption models have been proposed that aim to…

2014 The Astrophysical Journal
PROBA-2 70
Observational Characteristics of Coronal Mass Ejections without Low-coronal Signatures
DOI: 10.1088/0004-637X/795/1/49 Bibcode: 2014ApJ...795...49D

Berghmans, D.; Seaton, D. B.; D'Huys, E. +1 more

Solar eruptions are usually associated with a variety of phenomena occurring in the low corona before, during, and after the onset of eruption. Though easily visible in coronagraph observations, so-called stealth coronal mass ejections (CMEs) do not obviously exhibit any of these low-coronal signatures. The presence or absence of distinct low-coro…

2014 The Astrophysical Journal
PROBA-2 SOHO 66
Radio Imaging of a Type IVM Radio Burst on the 14th of August 2010
DOI: 10.1088/0004-637X/782/1/43 Bibcode: 2014ApJ...782...43B

Krucker, S.; Bain, H. M.; Saint-Hilaire, P. +1 more

Propagating coronal mass ejections (CMEs) are often accompanied by burst signatures in radio spectrogram data. We present Nançay Radioheliograph observations of a moving source of broadband radio emission, commonly referred to as a type IV radio burst (type IVM), which occurred in association with a CME on the 14th of August 2010. The event was we…

2014 The Astrophysical Journal
PROBA-2 51
Observations of a Hybrid Double-streamer/Pseudostreamer in the Solar Corona
DOI: 10.1088/2041-8205/787/1/L3 Bibcode: 2014ApJ...787L...3R

Seaton, D. B.; Bethge, C.; Yeates, A. R. +2 more

We report on the first observation of a single hybrid magnetic structure that contains both a pseudostreamer and a double streamer. This structure was originally observed by the SWAP instrument on board the PROBA2 satellite between 2013 May 5 and 10. It consists of a pair of filament channels near the south pole of the Sun. On the western edge of …

2014 The Astrophysical Journal
PROBA-2 36
Bridging EUV and White-Light Observations to Inspect the Initiation Phase of a "Two-Stage" Solar Eruptive Event
DOI: 10.1007/s11207-014-0585-8 Bibcode: 2014SoPh..289.4545B

Seaton, D. B.; Habbal, S. R.; Bain, H. M. +2 more

The initiation phase of coronal mass ejections (CMEs) is a very important aspect of solar physics, as these phenomena ultimately drive space weather in the heliosphere. This phase is known to occur between the photosphere and low corona, where many models introduce an instability and/or magnetic reconnection that triggers a CME, often with associa…

2014 Solar Physics
PROBA-2 SOHO 31
Study of Extreme-ultraviolet Emission and Properties of a Coronal Streamer from PROBA2/SWAP, Hinode/EIS and Mauna Loa Mk4 Observations
DOI: 10.1088/0004-637X/781/2/100 Bibcode: 2014ApJ...781..100G

Slemzin, V.; Goryaev, F.; Vainshtein, L. +1 more

Wide-field extreme-ultraviolet (EUV) telescopes imaging in spectral bands sensitive to 1 MK plasma on the Sun often observe extended, ray-like coronal structures stretching radially from active regions to distances of 1.5-2 R , which represent the EUV counterparts of white-light streamers. To explain this phenomenon, we investigated th…

2014 The Astrophysical Journal
Hinode PROBA-2 29
Multiwavelength observation of a large-scale flux rope eruption above a kinked small filament
DOI: 10.1051/0004-6361/201323269 Bibcode: 2014A&A...572A..83K

Kumar, Pankaj; Cho, Kyung-Suk

We analyzed multiwavelength observations of a western limb flare (C3.9) that occurred in AR NOAA 111465 on 30 April 2012. The high-resolution images recorded by SDO/AIA 304, 1600 Å and Hinode/SOT Hα show the activation of a small filament (rising speed ~40 km s-1) associated with a kink instability and the onset of a C-class flare near …

2014 Astronomy and Astrophysics
Hinode PROBA-2 26