Abstract:
We present the multiwavelength observations of a flux rope that was trying to
erupt from NOAA AR 11045 and the associated M-class solar flare on 12 February 2010
using space-based and ground-based observations from TRACE, STEREO, SOHO/MDI,
Hinode/XRT, and BBSO. While the flux rope was rising from the active region, an M1.1/2F
class flare was triggered near one of its footpoints. We suggest that the flare triggering was
due to the reconnection of a rising flux rope with the surrounding low-lying magnetic loops.
The flux rope reached a projected height of ≈ 0.15Rꙩ with a speed of ≈ 90 km s-¹ while the
soft X-ray flux enhanced gradually during its rise. The flux rope was suppressed by an over-
lying field, and the filled plasma moved towards the negative polarity field to the west of its
activation site. We found the first observational evidence of the initial suppression of a flux
rope due to a remnant filament visible both at chromospheric and coronal temperatures that
evolved a couple of days earlier at the same location in the active region. SOHO/MDI mag-
netograms show the emergence of a bipole ≈ 12 h prior to the flare initiation. The emerged
negative polarity moved towards the flux rope activation site, and flare triggering near the
photospheric polarity inversion line (PIL) took place. The motion of the negative polarity
region towards the PIL helped in the build-up of magnetic energy at the flare and flux rope
activation site. This study provides unique observational evidence of a rising flux rope that
failed to erupt due to a remnant filament and overlying magnetic field, as well as associated
triggering of an M-class flare.
