Solar Prominences: Observations

Parenti, S.

doi:10.12942/lrsp-2014-1

Cited by 280 publications

(247 citation statements)

References 275 publications

Supporting

Mentioning

234

Contrasting

Order By: Relevance

“…Associate releases of mass and/or energy are called flares, eruptive prominences and CMEs, depending on the emission and dynamics observed (for reviews see, Benz 2008; Fletcher et al 2011;Mackay et al 2010;Parenti 2014;Hudson et al 2006;Webb and Howard 2012). Flares involve sudden enhancements of electromagnetic radiation, caused by accelerated particles and excessive heating of the coronal plasma.…”

Section: Dynamic Evolution: Eruptive Phenomenamentioning

confidence: 99%

The magnetic field in the solar atmosphere

Wiegelmann

Thalmann

Solanki

2014

Astron Astrophys Rev

172

125

View full text Add to dashboard Cite

This publication provides an overview of magnetic fields in the solar atmosphere with the focus lying on the corona. The solar magnetic field couples the solar interior with the visible surface of the Sun and with its atmosphere. It is also responsible for all solar activity in its numerous manifestations. Thus, dynamic phenomena such as coronal mass ejections and flares are magnetically driven. In addition, the field also plays a crucial role in heating the solar chromosphere and corona as well as in accelerating the solar wind. Our main emphasis is the magnetic field in the upper solar atmosphere so that photospheric and chromospheric magnetic structures are mainly discussed where relevant for higher solar layers. Also, the discussion of the solar atmosphere and activity is limited to those topics of direct relevance to the magnetic field. After giving a brief overview about the solar magnetic field in general and its global structure, we discuss in more detail the magnetic field in active regions, the quiet Sun and coronal holes.

show abstract

Section: Dynamic Evolution: Eruptive Phenomenamentioning

confidence: 99%

The magnetic field in the solar atmosphere

Wiegelmann

Thalmann

Solanki

2014

Astron Astrophys Rev

172

125

View full text Add to dashboard Cite

show abstract

“…In evaporation-condensation models, chromospheric plasma is evaporated owing to thermal non-equilibrium and ultimately condensed in the corona to form cool filament threads (Karpen et al 2005;Xia et al 2012;Liu et al 2012;Berger et al 2012). The dynamic evolution at the footpoints of the filaments could provide important information for our understanding of the formation mechanism of the filaments (Parenti 2014;.…”

Section: Introductionmentioning

confidence: 99%

Subarcsecond bright points and quasi-periodic upflows below a quiescent filament observed by IRIS

Zhang

2016

A&A

View full text Add to dashboard Cite

Context. The new Interface Region Imaging Spectrograph (IRIS) mission provides high-resolution observations of UV spectra and slit-jaw images (SJIs). These data have become available for investigating the dynamic features in the transition region (TR) below the on-disk filaments. Aims. The driver of "counter-streaming" flows along the filament spine is still unknown yet. The magnetic structures and the upflows at the footpoints of the filaments and their relations with the filament mainbody have not been well understood. We study the dynamic evolution at the footpoints of filaments in order to find some clues for solving these questions. Methods. Using UV spectra and SJIs from the IRIS, along with coronal images and magnetograms from the Solar Dynamics Observatory (SDO), we present the new features in a quiescent filament channel: subarcsecond bright points (BPs) and quasi-periodic upflows.Results. The BPs in the TR have a spatial scale of about 350−580 km and lifetimes of more than several tens of minutes. They are located at stronger magnetic structures in the filament channel with a magnetic flux of about 10 17 −10 18 Mx. Quasi-periodic brightenings and upflows are observed in the BPs, and the period is about 4−5 min. The BP and the associated jet-like upflow comprise a "tadpole-shaped" structure. The upflows move along bright filament threads, and their directions are almost parallel to the spine of the filament. The upflows initiated from the BPs with opposite polarity magnetic fields have opposite directions. The velocity of the upflows in the plane of sky is about 5−50 km s −1 . The emission line of Si IV 1402.77 Å at the locations of upflows exhibits obvious blueshifts of about 5−30 km s −1 , and the line profile is broadened with the width of more than 20 km s −1 . Conclusions. The BPs seem to be the bases of filament threads, and the upflows are able to convey mass for the dynamic balance of the filament. The "counter-streaming" flows in previous observations may be caused by the propagation of bi-directional upflows initiated from opposite polarity magnetic fields. We suggest that quasi-periodic brightenings of BPs and quasi-periodic upflows result from small-scale oscillatory magnetic reconnections, which are modulated by solar p-mode waves.

show abstract

“…Some very recent and comprehensive summaries of the various models that can trigger the eruption of filaments and CMEs are Aulanier et al (2010), Schmieder et al (2013), Aulanier (2014), Parenti (2014) and references therein; the "magnetic breakout model" (Antiochos 1998;Antiochos et al 1999); a [250 , 200 ], enclosed in a white square. A movie available online shows the temporal evolution of the whole visible hemisphere from 21:00 to 22:09 UT in the AIA 304 Å channel.…”

Section: Introductionmentioning

confidence: 99%

Supergranular-scale magnetic flux emergence beneath an unstable filament

Palacios

Cid

Guerrero

et al. 2015

A&A

View full text Add to dashboard Cite

Aims. Here we report evidence of a large solar filament eruption on 2013, September 29. This smooth eruption, which passed without any previous flare, formed after a two-ribbon flare and a coronal mass ejection towards Earth. The coronal mass ejection generated a moderate geomagnetic storm on 2013, October 2 with very serious localized effects. The whole event passed unnoticed to flarewarning systems. Methods. We have conducted multi-wavelength analyses of the Solar Dynamics Observatory through Atmospheric Imaging Assembly (AIA) and Helioseismic and Magnetic Imager (HMI) data. The AIA data on 304, 193, 211, and 94 Å sample the transition region and the corona, respectively, while HMI provides photospheric magnetograms, continuum, and linear polarization data, in addition to the fully inverted data provided by HMI.Results. This flux emergence happened very close to a filament barb that was very active in mass motion, as seen in 304 Å images. The observed flux emergence exhibited hectogauss values. The flux emergence extent appeared just beneath the filament, and the filament rose during the following hours. The emergence acquired a size of 33 in ∼12 h, about ∼0.16 km s −1 . The rate of signed magnetic flux is around 2 × 10 17 Mx min −1 for each polarity. We have also studied the eruption speed, size, and dynamics. The mean velocity of the rising filament during the ∼40 min previous to the flare is 115 ± 5 km s −1 , and the subsequent acceleration in this period is 0.049 ± 0.001 km s −2 . Conclusions. We have observed a supergranular-sized emergence close to a large filament in the boundary of the active region NOAA11850. Filament dynamics and magnetogram results suggest that the magnetic flux emergence takes place in the photospheric level below the filament. Reconnection occurs underneath the filament between the dipped lines that support the filament and the supergranular emergence. The very smooth ascent is probably caused by this emergence and torus instability may play a fundamental role, which is helped by the emergence.

show abstract

Solar Prominences: Observations

Cited by 280 publications

References 275 publications

The magnetic field in the solar atmosphere

The magnetic field in the solar atmosphere

Subarcsecond bright points and quasi-periodic upflows below a quiescent filament observed by IRIS

Supergranular-scale magnetic flux emergence beneath an unstable filament

Contact Info

Product

Resources

About