Explanation:
Does the Sun change as it rotates?
Yes, and the changes can vary from subtle to dramatic.
In the
featured time-lapse sequences,
our Sun -- as imaged by
NASA's
Solar Dynamics Observatory --
is shown rotating though an entire month in 2014.
In the large image on the left, the solar
chromosphere is depicted in
ultraviolet light, while the smaller and lighter
image to its upper right simultaneously shows the more familiar solar
photosphere in
visible light.
The rest of the inset six Sun images highlight
X-ray emission
by relatively rare iron atoms located at different heights of the
corona, all
false-colored
to accentuate differences.
The Sun takes just under a month to
rotate
completely -- rotating fastest at the equator.
A large and active
sunspot region rotates into view soon after the video
starts.
Subtle effects include changes in
surface texture and the shapes of active regions.
Dramatic effects include numerous flashes in active regions, and fluttering and
erupting prominences visible all around the Sun's edge.
Presently,
our Sun
is passing an unusually low
Solar minimum in activity of its
11-year
magnetic cycle.
As the video ends, the same large and
active sunspot region
previously mentioned rotates back into view, this time
looking different.
