Observation of a Flare and Filament Eruption in Lyman-α on 8 September 2011 by the PRoject for OnBoard Autonomy/Large Yield Radiometer (PROBA2/LYRA)
Abstract
The Large Yield Radiometer (LYRA) instrument onboard the PRoject for OnBoard Autonomy (PROBA2) observes the solar irradiance in four channels in the UV-EUV. One of these channels is centered around the hydrogen line at 121.6 nm. The solar Lyman-α emission line is an optically thick line mostly formed in the chromosphere. Although it is one of the strongest lines of the solar spectrum, only a limited number of instruments provided observations of solar flares in Lyman-α , and those observations differ significantly in shape, durations, and amplitude. We focus on an event that happened on 8 September 2011 (SOL2011-09-08T15:46). This event, an M6.7 flare, was associated with a filament eruption that happened during the decaying phase of the flare. Most of the irradiance fluctuations observed in the Lyman-α time series are synchronized with nonthermal emission fluctuations, as is predicted by flare models. However, there is a late-phase peak in Lyman-α observations that rather correlates with the timing of the filament eruption. We demonstrate that the eruption of the filament is at the origin of this peak.
- Publication:
-
Solar Physics
- Pub Date:
- March 2022
- DOI:
- 10.1007/s11207-022-01963-0
- Bibcode:
- 2022SoPh..297...36W
- Keywords:
-
- Irradiance;
- Lyman-α;
- Flare;
- Filament eruption