July 29, 2012
Photographer: John Chumack; John’s Web site
Summary Author: John Chumack; Jim Foster
The photo above shows a monster of a sunspot as seen from my backyard observatory near Dayton, Ohio on July 9, 2012. This is Sunspot 1520 (Active Region 11520), which had just rounded the Sun’s eastern limb. It’s estimated to extend 11 Earth diameters end to end. This active region was facing Earth when a blob of plasma, known as a coronal mass ejection or CME, was expelled from the Sun's photosphere. As a result, some residents of the mid-latitudes of the Earth’s Northern Hemisphere were treated to impressive aurora displays several days following the CME.
Photo details: I captured these white light images using a Lunt Herschel Solar Wedge filter setup; 80mm University Optics Refractor; 2x Barlow lens; DMK (21 + 31) fire wire cameras; 1/1000 sec. exposure. I also used a Lunt 60mm/50F H-alpha scope to capture the Hydrogen Alpha light that was shot as well; 1/54 sec. exposure.