A prominence is a large, bright, gaseous feature extending outward from the Sun’s surface, often in a loop shape. Prominences are anchored to the Sun’s surface in the photosphere, and extend outwards into the Sun’s corona. While the corona consists of extremely hotionized gases, known as plasma, which do not emit much visible light, prominences contain much cooler plasma, similar in composition to that of the chromosphere. The prominence plasma is typically a hundred times cooler and denser than the coronal plasma. A prominence forms over timescales of about a day, and prominences may persist in the corona for several weeks or months. Some prominences break apart and may then give rise to coronal mass ejections.

• Imaging telescopes or lenses: TS INDIVIDUAL 152/900
• Imaging cameras: ZWO ASI174MM
• Mounts: Skywatcher EQ6 Pro EQ6 Pro Skyscan
• Filters: Daystar Filters Quark H-Alpha Chromosphere filter
• Date: April 25, 2015
• Focal length: 3860
• Locations: Osservatorio a casa, Dolianova , Cagliari, Italy

Author: Alessandro Bianconi

SPONLI is a project about astrophotography, for amateur astronomers.