7 March th SECCHI Consortium Meeting Observing prominence dynamics with STEREO David Alexander, Rui Liu, and Holly Gilbert Rice University

7 March th SECCHI Consortium Meeting 2007 Student opportunities Support is available for a small number of international students Contact: David Alexander July 29 - August 3, in Whistler, BC, Canada. for latest information

7 March th SECCHI Consortium Meeting The ‘Failed’ Eruption: 25 May 2002 A series of TRACE EUV (Fe XII/XXIV 195A) images shows the morphological evolution of the filament. Note the apparent kinking of the filament, the stagnation of the eruption, and the draining of material. No CME detected, but an M2 flare 18:00:2118:03:0618:04:3218:05:32 18:06:3218:07:3218:08:3218:22:14 Alexander, Liu & Gilbert, 2006

7 March th SECCHI Consortium Meeting keV RHESSI hard X-ray contours. The yellow arrows indicate the coronal sources and the red arrow points to the projected crossing point of the two filament legs. Note that Source 2 lies close to this crossing point, where one might expect the two legs to interact via reconnection. Source 2 Source 1 Presence of Current Sheets

7 March th SECCHI Consortium Meeting Simulations The figure shows current density iso- surfaces during the evolution of the kink instability. The helically deformed flux rope (red), the helical current sheet (purple), and the vertical current sheet (yellow) are visible. Details are described in Torok & Kliem (2004). purple red yellow

7 March th SECCHI Consortium Meeting Mass Flows: 25 May 2002 Velocity information provided by MLSO/CHIP instrument in HeI 1038nm Max. velocity = 100 km/s Initial expansion followed by mass draining and twisting motions Velocity information important for determining whether structure is kinked or not.

7 March th SECCHI Consortium Meeting Partial Eruption: 31 Oct 2005 Liu, Alexander & Gilbert, 2007a Kinking structure associated with partial eruption of prominence cavity Kinking inferred from dynamic motions in intensity and velocity signatures Reconnection between filament channel and polar crown arcade mediated eruption

7 March th SECCHI Consortium Meeting Velocity: 31 Oct 2005 For this orientation, velocity information is crucial to determine configuration.

7 March th SECCHI Consortium Meeting Cavity Eruption: 31 Oct 2005 Partial eruptions can involve all, some, or none of the prominence mass.

7 March th SECCHI Consortium Meeting Kinking and Partial Eruptions Gilbert et al. (2001) – kinking not considered Gibson and Fan (2006) – kinking crucial

7 March th SECCHI Consortium Meeting Kinking and Partial Eruptions Both simulations and observations indicate that the degree of kinking is not only important for driving eruption but also determines the nature of the eruption.

7 March th SECCHI Consortium Meeting STEREO/SECCHI The stereoscopic viewpoints of EUVI, COR-1, and COR-2 are crucial for this study. Filaments/Prominences are relatively easy to visualize in 3D We will be able to a.Determine whether the filament is kinked or not b.Follow the evolution of the kinked structure into the corona c.Provide ‘true’ 3D velocity d.Help disentangle the Doppler signals from MLSO/CHIP

7 March th SECCHI Consortium Meeting STEREO/SECCHI

7 March th SECCHI Consortium Meeting 25 May 2001 see Rui directory Potential for EUVI/COR-1/COR-2 Liu, Alexander & Gilbert, 2007b

7 March th SECCHI Consortium Meeting Velocity information provides additional dynamical context

7 March th SECCHI Consortium Meeting Other issues Importance of kink instability vs. kinked configuration  Possibly different initiation mechanisms (dynamic vs. triggered) Role of reconnection – where and when?  Current sheet formation, flare production, implications for hard X-ray production in filament-driven flaring. Role played by mass in filament eruptions  Possibly different initiation mechanisms (dynamic vs. triggered) Effect of composition (H/He) on eruptive process (Gilbert & Kilper, 2007)  Absorption observed by EUVI can play a role.