Three Sunspots

Mild November Conditions

November 10th was the final day of a rare three-day stretch of cloudless weather in Williamsburg! Just after noon soft breezes and a temperature of 71 degrees lured me outside to image the Sun. Three small sunspots were arranged in a disc-spanning triangle. A few modest prominences decorated the rim.

I screwed a ZWO 1600 camera directly to the blocking filter diagonal of my Lunt 100 mm solar telescope. The 1600 imaging chip is big enough to capture the entire solar disc at prime focus. In this prime focus configuration (with no magnifying Barlow lens) the full disc image is obtained all at once and doesn't require assembling separate panels into a mosaic. The chip is so big I could define a small portion as a region of interest large enough to include the whole Sun. The first image below shows the full disc and prominences captured by the 1600 camera. You need to enlarge the image by clicking on it in order to properly see all the details.In my experience the 1600 camera has never been good for solar imaging. The chip doesn't seem to have a uniform response over its entire surface. The effect isn't apparent in the previous image because I was able to put the Sun's image on part of the chip where the nonuniform response was minimal.

Separate images of the three sunspots were made with ZWO 174 camera and 3X Barlow lens. First, southern hemisphere sunspot 2894 featured a split umbra and accompanying curved dark filament.Next, solitary sunspot 2893 was nearly ready to rotate out of sight around the western solar limb.Finally, sunspot 2895  displayed only tiny, nearly indistinguishable umbras in the next image. 

November 10th wasn't a particularly dramatic day for solar features, but it's nice to see even modest activity after recent years of featureless Sun!