AR12546 is the symbol of sunspot group (Active Region) that has been passing over sun disk since one week. It is pretty huge and can be spotted without any optical instrument but WITH some kind of solar filter (never look directly to Sun). Last weekend eventually I have been able to take a look at this monster and also take some pictures.
Sunspot is quite dynamic, it’s possible to notice changes within 1 hour. Below two pictures of this region made with SCT8″, ND5 + Baader SC filter and ASI290MM camera (Earth picture is for size comparison):
You can easily notice Sun cellular granules, a photospheric feature of size about 1000km that cover whole Sun surface except the areas occupied by sunspots.