Solar Polar Rays Are Not Polar

We discuss the nature of polar rays, based on limb synoptic images constructed from Yohkoh/SXT and SORafElT data. In the literature, polar rays and polar plumes are often mentioned interchangably. We find that polar rays are projection effects caused by hot plasma from equatorial active areas and are not physically associated with the coronal polar holes. Instead, the rise in number and strength of polar rays toward solar activity maximum may be responsible for hiding the polar holes and polar plumes.