2012 Sun Photo Gallery
This page contains links to recent solar images taken from Bifrost Astronomical Observatory in Portal, AZ.
Most of these images were captured with a telescope equipped with a hydrogen-alpha (or H-alpha) filter. H-alpha is a narrow line at the red end of the visible spectrum. It is caused by a transition in the hydrogen atom when an electron drops from its third to second lowest energy level.
The Sun is composed primarily of hydrogen and its upper atmosphere or chromosphere glows in the red light of H-alpha. A telescope with an H-alpha filter can reveal amazing structures in the chromosphere that are not visible in white light. Enormous prominences rise above the Sun's surface reaching altitudes of 150,000 kilometers (90,000 miles) or more. When seen silhouetted against the solar disk prominences are then called filaments. They often underlie coronal mass ejections and are important to the prediction of space weather. Spicules are long thin tubes of luminous gas that can change in a matter of minutes. Powerful magnetic explosions known as solar flares form in the most active surface regions and eject clouds of electrons, ions, and atoms through the Sun's corona into space.
Click on the thumbnails below to see larger images and photo details.