Η Ηλιακη δραστηριοτητα με χρηση οπτικων φιλτρων.

Gradient Sun


Using a gradient filter on imagery captured by NASA's Solar Dynamics Observatory (SDO) helped create this stunning display of sharply defined coronal loops on the sun next to fuzzier, cooler areas that are sometimes referred to as "moss" due to their moss-like appearance. Credit: NASA/Goddard Space Flight Center