Large Sunspot Group AR 9393
The largest
sunspot group of the past ten years
crossed the surface of the
Sun late last month and early this month.
The group was designated
Active Region 9393
as it was the 9393rd region identified since
counting officially began in 1973.
The number of
active regions on the Sun is high recently because the Sun is reaching the maximum of its current
11-year cycle
of magnetic activity.
The above time-lapse sequence shows AR 9393 as it evolved from 27 March to April 2 to become over
10 times larger than
our Earth.
Just after the end of the movie, on April 2,
AR 9393 unleashed the
largest solar flare of the
last 25 years.
Luckily, the
flare was not pointed toward the Earth, or
flare particles might have damaged satellites or even
caused local electrical blackouts.
Yesterday morning, however, a less powerful flare was
ejected from a different sunspot group (AR 9415)
toward Earth that has already caused radio interference.
This and solar activity from Monday should cause significant aurorae
over the next two nights.
Will the
above sunspot group remain as its region rotates back
into view in a few days, or will it break up on the far side of the Sun?
Currently, no one knows for sure.