Drax Spacex Posted August 29, 2021 Share Posted August 29, 2021 A few hours after the M4.7 flare, in AIA 304 a filament lifted off just north of the equator at about 28/1300. Could that be Earth-directed? Would a filament eruption be visible in LASCO and Stereo COR2? Link to comment Share on other sites More sharing options...
Marcel de Bont Posted August 29, 2021 Share Posted August 29, 2021 Well spotted. Yes it would indeed be visible if ejecta managed to escape the Sun's gravity. I do however not see a CME on SOHO/LASCO which could come from this filament eruption so I think most if not all of the ejecta fell back onto the Sun's surface. There is a CME visible heading west but that must have been from a limb or far side event. 1 1 Link to comment Share on other sites More sharing options...
Drax Spacex Posted August 29, 2021 Author Share Posted August 29, 2021 Thanks for your analysis and information - much appreciated! Yes it likely dispersed and fell back to the Sun. Link to comment Share on other sites More sharing options...
Fulguritics Posted August 29, 2021 Share Posted August 29, 2021 Velocity must exceed 618 km/s for massive, non-relativistic escape from solar gravitation. 1 Link to comment Share on other sites More sharing options...
Drax Spacex Posted August 31, 2021 Author Share Posted August 31, 2021 Today's SWPC Forecast Discussion does include mention of this filament as a possible contributor to elevated storm levels on Thursday. "G2 (Moderate) storm levels are forecast for 02 Sep due to the anticipated arrival of the 28 Aug CME combined with a CME from a filament that disappeared from near center meridian at around 1800 UTC on 28 Aug." Presumably there's some uncertainty about whether this disappearing solar filament (DSF) collapsed or erupted. I suppose if it was a narrow eruption and directly aimed at Earth, it could be rendered invisible in LASCO imagery, confined within the blacked-out central area. I believe in Stereo COR2 there was a narrow wisp of an eruption visible near the equatorial plane - that may be what SWPC saw and why they included it in their forecast discussion. Link to comment Share on other sites More sharing options...
Marcel de Bont Posted August 31, 2021 Share Posted August 31, 2021 To be honest I did relook at SOHO/LASCO and only see the M4.7 CME. Yes that CME could have an earth-directed component but it is unimpressive I doubt it will make much of an impact. The filament CME is unnoticeable to me so the G2 forecast surprises me. 1 Link to comment Share on other sites More sharing options...
Drax Spacex Posted September 3, 2021 Author Share Posted September 3, 2021 On 8/31/2021 at 1:03 PM, Marcel de Bont said: To be honest I did relook at SOHO/LASCO and only see the M4.7 CME. Yes that CME could have an earth-directed component but it is unimpressive I doubt it will make much of an impact. The filament CME is unnoticeable to me so the G2 forecast surprises me. And you were right! Link to comment Share on other sites More sharing options...
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