Plasma Arches on the Western Limb

Solar Prominences on February 13, 2009
Sketch and Details by Erika Rix

2009 Feb 13, 1600UT – 1700UT

Solar prominences in h-alpha, western limb

PCW Memorial Observatory, Zanesville, Ohio USA
Erika Rix

DS 60mm Maxscope, LXD75, 21-7mm Zhumell
Sketch created scopeside with black Strathmore Artagain paper, white Conte’ crayon and pencil, white Prang watercolor pencil.

Temp: 3° C, Humidity 60%
Seeing: Wilson 3, Transparency: poor
Scattered, winds 7mph from NNW
Alt: 34.4, Az: 159.2

Approximately 30° inward from the eastern limb, a crescent-shaped plage was seen with a dark dot during my h-alpha observation. No AR was noted in white light. There were a few proms scattered about to the north and south, but the prominences on the western limb really stood out. At first glance it looked like two detached proms, but adjusting the outer etalon and increasing magnification, that section of limb came alive with prominence structure.

North is to the 4.5 o’clock position and west is the 2.5 o’clock position in my sketch.