Low clouds dotted the western horizon at sunset in Tucson tonight. However, that is not all bad. They can slightly dim the setting Sun making it easier to photograph sunspots. Today there were plenty of good sized sunspots. These pics were taken with my Canon 60D and 70-300mm zoom lens (at 300mm).
If you want to compare it to today's Sun, check out the Spaceweather archive. Note, due to an effect called field rotation, the Sun is my pics is rotated 90 degrees clockwise relative to the image on Spaceweather.
Reprinted with permission from the Half-Astrophysicist Blog.
Gorgeous. Field rotation? Hmmm.
ReplyDeleteIs that a sunspot at about 11 o'clock in the first picture?
ReplyDeleteAs always, nice pics, hale.
Yes, the biggest sunspot is at about 11.
ReplyDeleteField rotation is an effect common to al-az mounts. Think of looking at the Sun when it is directly south. West is on your right and east is on your left. Now imagine several hours later right at sunset. The west side of the Sun is on the bottom and the east side is on the top. It has rotated by 90 degrees. If you have an mount that is aligned with Earth's rotational axis, then you won't get field rotation.