The Sun in Ca K-line light, Saturn and Jupiter April 30

A DMK21AS camera was fitted with a short adapter, a focal reducer and a Baader Ca K-line filter. This filter gives a relatively wide bandpass of 9nm centred on the Ca K-line. Overlapping areas of the Sun were imaged with 5000 frame AVIs using a Helios, 6", f/5 refractor fitted with a Baader photographic grade solar filter. (note, this filter is not a visual filter and additional stacked, neutral density filters were required to make it safe for centering the Sun). The resulting images were stitched into a single image:

The camera setup

Full disk image of the Sun in Ca K-line light

Without the focal reducer, details of AR1731, 1730 and 1735 were captured:

The seeing was not as good as the previous night. An 8" SCT was used with a DFK21AS camera to capture a 5,000 frame AVI at 15fps and 1/15s:

Jupiter was very low in the western sky with poor seeing and detail was not resolved:

Steve Wainwright