Monday, 5 May 2014

AR12049 & Departing Active Regions - 5th May

This is my favourite image from the morning of the May Day bank holiday monday.  I woke up to beautifully clear blue skies however I knew I only had less than an hour to get any imaging in before rapidly approaching weather fronts coming in off the Atlantic brought their attendant cloud and later rain.  Given that it was only just after 8am I knew the seeing was going to be as steady as it ever is on spring days and so decided to make use of the small imaging window and take some shots in CaK wavelengths.  Imaging in the near ultraviolet is prone to poor seeing conditions, so my usual method is to shoot as many avis as possible and then after stacking sort through them and find the best image.  Not only is this my best image but also my favourite image from today, the detail in and around the active region and large spot is about as good as it gets at this resolution.  There's even faint detail visible within the umbra of the large spot.  The image was taken with the 80mm scope running at f20, 1600mm focal length, with the homebrew CaK filter and Beloptik triband ERF, and the DMK31 camera.