List of Figures

View Image Figure 1:
A prominence at the limb and its filament part on the disk as seen by SDO/AIA. The off-limb prominence appears bright in the 304 Å passband (left panel, chromospheric emission) while the on-disk part, the filament, appears darker than the surrounding quiet Sun suggesting absorption effects. The filament is still dark in the 171 Å band on the disk image (right panel, coronal emission) and off-limb it is almost invisible, suggesting the lack of emission at these temperatures. Courtesy of NASA/SDO and the AIA science team.
View Image Figure 2:
Left: image of the Sun as seen in the He ii 304 Å channel on SOHO/EIT, on 23 February 2004, revealing three dark filaments (arrows). One of them extends over almost a solar diameter. Right: image of the Sun in Hα on the same day revealing different details of these three structures. Credits: ESA/NASA/EIT; Catania Astrophysical Observatory.
View Image Figure 3:
Left: the first proposed magnetic topology for prominence from Kippenhahn–Schlüter (from Gilbert et al., 2001). Middle: sheared arcade configuration (from DeVore and Antiochos, 2000). Right: flux rope configuration (from Amari et al., 2003b). Images reproduced by permission, copyright by AAS.
View Image Figure 4:
VAULT Lyα images of a prominence at the limb (left) and a filament on the disk (right) observed on June 14, 2002 (see Vourlidas et al., 2010).
View Image Figure 5:
Hα high resolution image of a filament taken on 6 October 2004 by the Dutch Open Telescope (DOT). The green circles marks the barbs.
View Image Figure 6:
SDO/AIA 171 Å detail of a filament observed on 11 November 2011. Barbs are clearly visible in absorption at the limb and on disk. Courtesy of NASA/SDO/AIA.
View Image Figure 7:
Detail of a complex active region in Hα showing an empty filament channel (between the white arrows) with aligned fibrils along the PIL. Image reproduced by permission from Martin (1998b), copyright by Springer.
View Image Figure 8:
High-resolution image on the solar limb obtained with Hinode/SOT Ca ii H-line 3968 Å. Image reproduced by permission from Okamoto et al. (2007); copyright by AAAS.
View Image Figure 9:
Hα line center image of a prominence at the West limb on 22 November 1995. Credits: Big Bear Solar Observatory/New Jersey Institute of Technology.
Watch/download Movie Figure 10: (mov-Movie; 12201 KB)
Movie: One of the first prominence eruptions observed by SDO/AIA. Movie taken from External Link Courtesy of SDO (NASA) and the AIA consortium.
View Image Figure 11:
Radiance of the H i Ly continuum as a function of wavelength in a prominence observed in 1999. The crosses indicate data corrected for temporal variations. The solid curve represents the fit to the corrected data. Image reproduced by permission from Parenti et al. (2005); copyright by ESO.
View Image Figure 12:
Line intensity profiles along a cut perpendicular to a filament axis observed on 14 June 2002 on the disk and shown in Figure 4 right. Image reproduced by permission from Vial et al. (2012); copyright by ESO.
View Image Figure 13:
Differential Emission Measure for two prominences (top) and the QS (bottom). The prominence DEMs were inferred with 20% uncertainty using 1999 (solid line, Parenti and Vial, 2007) and 2004 (dashed-line, Gunár et al., 2011) SOHO/SUMER data. The dashed-line on the QS plot is the QS DEM available in the CHIANTI database. Bottom image reproduced by permission from Parenti and Vial (2007), copyright by ESO.
View Image Figure 14:
Small cavity (left) and a large cavity (right) imaged in white-light polarization brightness from the MLSO Mk4 coronameter (top), and by the EIT telescope onboard the SOHO satellite, at 304 Å (middle) and 195 Å (bottom). In the 304 Å images, the prominences lying within the cavities are clearly visible. The small cavity is visible at 195 Å while the large cavity does not show up at this wavelength. Image reproduced by permission from Fuller and Gibson (2009); copyright by AAS.
View Image Figure 15:
Top: detail of the 2008 eclipse studied by Habbal et al. (2010). Second and third rows: close-up views of the prominence regions in Fe x, Fe xi, Fe xiii, and Fe xiv, 7878.6 Å continuum (the limb is oriented horizontally, at the bottom of the image). Bottom row: spectral line intensities normalized to their corresponding maximum values (y-axis) vs. P.A. (x-axis), at 1.05, 1.15, and 1.3R ⊙, with green = Fe x, dashed-green = Fe xi, red = Fe xiii, dashed-red = Fe xiv, and black = 7878.6 Å continuum. The horizontal dashed lines correspond to the radial distances, where the normalized emission-line intensities are plotted. Image reproduced by permission from Habbal et al. (2010), copyright by AAS.
View Image Figure 16:
(a) Image of a cavity and its prominence observed with Hinode/EIS Fe xii 195 Å. The green contour marks the edge of the prominence as seen from SOHO/EIT 304 Å. The blue and red contours show ± 7 km s–1 LOS velocity. (b) LOS velocity in Fe xii 195 Å. Image reproduced by permission from Schmit et al. (2009); copyright by AAS.
View Image Figure 17:
One-to-one chirality relationships for (1) fibril patterns, (2) filament spines and barbs, and (3) overlying arcades of coronal loops, are shown in each column. The patterns in the left column are dominant in the northern hemisphere and those in the right column are dominant in the southern hemisphere. Image reproduced by permission from Martin (1998a), copyright by ASP.
View Image Figure 18:
High-resolution Hα image of a chromospheric filament observed on October 30, 2002 at 14:46 UT. Upper right and lower left corners: Dextral and sinistral patterns. The small filament in the lower right corner exhibits both sinistral and dextral barbs. USAF, ISOON image courtesy D. Neidig; from work of A.A. Pevtsov; External Link
View Image Figure 19:
Observed thread crossings in an inverse S-shaped filament. Note that the filament is dextral. (a) High-resolution Hα data and line-of-sight magnetogram taken at BBSO. The positive flux density levels are represented by white contours, and the negative ones by black contours. (b – d) TRACE images at different times. Image reproduced by permission from Chae (2000); copyright by AAS.
View Image Figure 20:
Stokes parameters from a multi-line inversion of simultaneous and cospatial spectro-polarimetric observations of He i 10830 (left) and D3 (right) in a quiescent prominence, taken with THEMIS on 29 June 2007. Image reproduced by permission from Casini et al. (2009); copyright by AAS.
View Image Figure 21:
Detail of the vector photospheric magnetic field in regions around a filament channel observed on 11 December 2007. Arrows of equal length show the orientation of the horizontal component of the magnetic field vector. The field is directed mainly along the filament channel running from lower left to upper right, but over most of its length the field has inverse configuration: the arrows have a component directed from negative polarity (lower right) toward positive polarity (upper left). This is especially true in the naked bald patch region above and to the right of the center of the image where the filament channel is not flanked by strong plage. A naked bald patch region is characterized by an inverse configuration of the transverse field, while the longitudinal component is almost absent. The gray scale ranges from 0 (white) to 2000 Gauss (black). Low-polarization pixels where no inversion technique has been applied appear as white areas. Image reproduced by permission from Lites (2009), copyright by Springer.
View Image Figure 22:
Prominence at the limb as seen by Hinode/SOT in the Ca ii H-line 3968 Å spectral line on 2006 November 30. “D” indicates examples of bright downflow streams. “U” shows several dark inclusions in the sheet that are regions of turbulent upflow. “V” indicates dark “voids” that are not upflows. Image reproduced by permission from Berger et al. (2008), copyright by AAS.
View Image Figure 23:
QS (top) and quiescent prominence NTV (bottom) as functions of temperature derived using SOHO/SUMER observations on 8 October 1999. The different symbols are for lines emitted by different elements. Image reproduced by permission from (Parenti and Vial, 2007), copyright by ESO.
View Image Figure 24:
Classification scheme for solar filaments based on those of Tang (1987) and Tandberg-Hanssen (1995) where two new categories (c and d) are introduced by Mackay et al. (2008). (a) Filaments that form above the internal PIL of a single bipole are classified as IBR. (b) Those forming on the external PIL between bipoles or between bipoles and unipolar flux regions are classified as EBR. (c) Filaments that lie both above the internal PIL within a bipole and the external PIL outside the bipoles are classified as I/EBR. (d) Finally, those filaments that form in diffuse bipolar distributions (formed through multiple flux emergence) are classified as DBR. This category is expected to lie only at high latitudes. Image reproduced by permission from Mackay et al. (2008), copyright by Springer.
View Image Figure 25:
Evolution of the decaying NOAA region 10003 during June 2002, showing the fibril structures changing their orientation from nearly perpendicular to nearly parallel to the PIL, as the opposite-polarity sectors diffuse toward each other. Left panels: Hα filtergrams; middle panels: corresponding MDI magnetograms saturated at Blos = ± 50 G; right panels: magnetograms saturated at Blos = ± 7 G. Image reproduced by permission from Wang and Muglach (2007), copyright by AAS.
View Image Figure 26:
Map of the amplitude of the change of the velocity vector direction. The closer this quantity is to 1, the better the alignment between two vector fields. Black areas indicate the location where a lot of changes between horizontal velocities take place. The filament observed before the eruption is superimposed. The hexagon indicates the location where the filament eruption started. Image reproduced by permission from Roudier et al. (2008), copyright by ESO.
View Image Figure 27:
Hα intensity and velocity images observed using MSDP instrument at Meudon Solar Tower on 21 May 2008, at 09:00 UT. The left panel shows the line center intensity while the right panel shows, in grey scale, the dopplergram overlaid by contours of the filament. The white arrows mark the maximum (white) and minimum (black) velocities, respectively, +800 m/s and –200 m/s. The white circle indicates upward and downward flows at the end of one foot of the filament. Elongated areas of blue and red-shifts (marked by the arrows) suggest some twist along the filament body. Image reproduced by permission from Gosain et al. (2009), copyright by Springer.
View Image Figure 28:
Light curve and stackplots in X and Y directions showing the variation in the Hα filament intensity on 19 May 2007 prior to the filament eruption at around 12:50 UT. The top panel shows the total emission, the middle is the variation in Y intensity and the bottom is the variation in X intensity. Image reproduced by permission from Bone et al. (2009), copyright by Springer.
View Image Figure 29:
Liftoff and eruption of a filament observed with STEREO/EUVI. An oscillatory motion is clearly visible during the rising phase before the eruption. Courtesy of STEREO/EUVI consortium.
View Image Figure 30:
Left panel: evolution of the C i 1118.45 Å intensity along the SUMER slit; Middle panel: same for S iii/Si iii 1113 Å; Right panel: evolution of the Dopplergram along the SUMER slit observed at S iii/Si iii 1113 Å. Image reproduced by permission from Chen et al. (2008), copyright by ESO.
View Image Figure 31:
A SOHO/Lasco C2 image of a CME. The central bright helical structure is identified with the erupting filament. Credits: SOHO (ESA & NASA).
View Image Figure 32:
Left panel: a Solar Maximum Mission archive image showing the principal features of a CME Image reproduced by permission from van Driel-Gesztelyi and Culhane (2009), copyright by Springer. Right panel: schematic view of the CME features. Image reproduced by permission from (Forbes, 2000), copyright by AGU.
View Image Figure 33:
Prominence eruption interpreted as the result of a kink instability. TRACE 195 images overlaid onto RHESSI X-ray contours at 10%, 20%, 50%, and 80% of the peak intensity at 1220 keV (gray), and 2040 keV (black). Coronal sources are marked by white arrows. The integration time for each RHESSI image is 12 s around the time of the corresponding TRACE image. Image reproduced by permission from Liu and Alexander (2009), copyright by AAS.
View Image Figure 34:
Schematic diagrams showing asymmetric (left panel) and symmetric (right panel) eruption of a filament. The arrows indicate the direction of propagation along and separation away from the polarity inversion line of the SOHO/EIT 195 channel brightenings. Image reproduced by permission from Tripathi et al. (2006), copyright by ESO.
View Image Figure 35:
Accumulated change of the magnetic helicity as a function of time in AR 9502 on June 2001, prior to a flare and filament eruption. t = 0 corresponds to 13:00 UT on June 14. The error bar represents the standard deviation of the signal. The vertical lines indicate the start and end of the flare. Image reproduced by permission from Romano et al. (2005), copyright by ESO.
View Image Figure 36:
Big Bear Solar Observatory Hα images of active region 9077 on 19 July 2000 showing the counterclockwise rotation of the filament. The TRACE 1600 Å image shows the formation of flare ribbons which form a reverse-S shape and indicate negative helicity. Image reproduced by permission from Green et al. (2007), copyright by Springer.
View Image Figure 37:
Cartoon showing the geometry of simultaneous observation from STEREO A and B of a prominence eruption. Given the two different projected altitudes (RA and RB) and latitudes (ϕA and ϕB) of the same point P, knowing the angular distance γ between the two spacecrafts, it is possible to derive via triangulation the 3D coordinates of this point. Image reproduced by permission from Bemporad (2009), copyright by AAS.
View Image Figure 38:
The different steps needed to obtain the difference image by Artzner et al. (2010) and isolate the prominence from the rest of the data. The top panel shows the STEREO-A (right) and STEREO-B (left) images in epipolar orientation after the raw images have been centered and re-scaled. The middle panel shows the STEREO-B image projected onto the STEREO-A view (left) and the STEREO-A view (right). The bottom panel shows the difference of the two images in the middle panel. Image reproduced by permission from Artzner et al. (2010), copyright by Springer.