Monday 7 March 2011

CaK Full Disk 6th March 2011

Cak-Full-Disk-Colour-Small, originally uploaded by Mark Townley.

A very active sun today in CaK wavelengths. The image is showing signs of the astigmatism inherent in the prism of the CaK PST (this is the blurring at the bottom of the disk). I will be attempting to fix this in the week ahead by reseating the prism on it's mounting block. A visual inpspection reveals that the prism is currently out of alignment by several degrees. Removing and then reseating it should hopefully remedy this issue. The effect is less noticeable at longer focal lengths, although image quality here (in the following images) is diminished by atmospheric dimming due to the low altitude of the march sun.