Left: height versus time of the filament apex. Two plots are shown: triangles represent the uncorrected height data; and the solid line indicates the height after correcting of heliocentric angle projection. Error bars are computed considering the visual error on height and angle correction. Time starts from 21:00 UT and covers 1 h. In the last 38 min, the height starts increasing. A vertical bar marks the flare onset, at 21:43 UT. Right: height-time diagram, including LASCO C2 (diamonds) and C3 (asterisks) data.