A sweeping prominence, a huge cloud of relatively cool dense plasma is seen suspended in the Sun's hot, thin corona. At times, promineces can erupt, escaping the Sun's atmosphere. Emission in this spectral line shows the upper chromosphere at a temperature of about 60,000 degrees K (over 100,000 degrees F). Every feature in the image traces magnetic field structure. The hottest areas appear almost white, while the darker red areas indicate cooler temperatures. (Courtesy of Boston.com & SOHO/EIT consortium)
You can find more pictures at big picture.