7. The Grand Daddy prominence
Some filaments and
prominences can reach impressive sizes, and remain visible very
far above the solar disk.
This prominence was photographed in June 1946
again through a filter centered on H, and extends some
200000 km above the solar surface; the Earth would easily fit under
it. The bright arch at the bottom of the picture delineates the solar
limb.
Prominences
extending so far up above the photosphere are usually not static,
but are expanding outward in an eruptive phase, a phenomenon to
which we shall return below.