July Heat

Dripping Sweat

July and August bring heat and humidity to Williamsburg. Tropical conditions were discouraging on July 21st. Nevertheless, a clear morning sky tempted me to image some sunspots. After a dawn bike ride I hurried to set up the solar telescope as temperature rose into the lower 80's. By the time I started capturing images my shirt was drenched and sweat dripped from my head. Humid air was completely still. I needed a towel to keep from soaking my laptop and note papers.

As I've mentioned before, the Sun has been nearly featureless lately. When a couple of rare significant sunspots were present on July 21st I was motivated to observe them before they rotated out of view. The first image below is a 26-panel mosaic of the Sun's western side showing sunspot 2565 closest to the western limb with sunspot 2567 following further from the rim. A few small prominences sit on the limb. Unfortunately, subtle vertical bands are visible. For some reason flat fielding failed to remove the bands this time. Seeing was good, so features are sharp. (Click on the images for a larger view.) 

The next image is a close detailed view of the sunspot pair.

Most of the Sun was blank, as you can see from the first mosaic image above. On the eastern limb one dark filament floated near a prominence shown in the final image below.

Clear sky lasted just 33 minutes! As temperature rose toward 90 degrees clouds suddenly filled the sky. I struggled to capture a flat field frame between cloud gaps while suffering in the exhausting heat. Once all my equipment was moved inside I collapsed into a chair for a late breakfast. Later that afternoon we cooled off a bit on water slides at Water Country.