Explanation:
The
ultraviolet light emitted by eleven times ionized iron at temperatures
over 2 million degrees Farenheit was used to record the above picture of the
Sun on September 22, 2001, the date of that year's
autumnal equinox.
The image was made by
the
EIT camera onboard
the SOHO spacecraft, a space observatory which can continuously
observe the Sun.
Eleven times ionized iron is
atomic
iron with eleven of its electrons stripped away.
Here the electrons are stripped by the
frantic collisions with other atoms and electrons
which occur at the extreme temperatures in
the
Solar Corona.
Since electrons are negatively charged, the
resulting ionized iron atom is highly
positively charged.
Astronomer's "shorthand" for eleven times ionized iron is written
"Fe XII", the chemical
symbol for iron followed by a
Roman
numeral 12 (Fe I is neutral iron).
