Spicules are Bright and Dark

Abstract

I have tried to understand whether spicules appear dark or bright against the disk in Hα by comparing high resolution pictures in Hα and Caii K. Since the chromospheric structure is more apparent near active regions, I have first compared the Hα and K fibrils near an active sunspot; these are illustrated in my review paper (this Symposium, p. 161). The elongated fibrils in the active center appear similar to spicules, but much larger and more horizontal. K line pictures show bright features better, while Hα shows dark features better.

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