Pick of The Week
 
 

Elongated Filament (February 25, 2005)


Hi-res TIF (4.0M)


Hi-res TIF (968K)

Movies
MPEG large (5.9M), large (1.7M)
QT
large (1.6M), small (327K)

This ultraviolet image of the Sun shows a very long filament slanting up roughly at a 45 degree angle across much of the Sun, underneath a long and narrow coronal hole (22 Feb. 2005). Filaments are twisting masses of cooler ("only" 10,000 - 100,000 degrees Kelvin) gas contained by magnetic fields above the Sun's surface in the midst of the much hotter (~ 1,500,000 K) corona. And just to keep the terms straight, filaments are called prominences if observed on the Sun's limb or edge. Sometimes filaments erupt, though they can remain stable for weeks at a time. This particular filament was already there 28 days ago (one solar rotation earlier), as were the two coronal holes. While filaments are fairly common, this one is longer than most that we have seen. It will be interesting to see how they appear as the Sun's rotation brings them over the edge of the Sun beginning around Feb. 25. The filament is particularly well visible in this H-alpha image obtained at the Kanzelhoehe Solar Observatory.

The video shows the filament virtually unchanged for almost two days earlier in the week. The close observer will detect (around 10:00 UT on Feb. 22) a small coronal mass ejection as it blasts out into space from the lighter, upper active region on the right edge of the Sun.

Previous Picks of the Week

SOHO began its Weekly Pick some time after sending a weekly image or video clip to the American Museum of Natural History (Rose Center) in New York City. There, the SOHO Weekly Pick is displayed with some annotations on a large plasma display.

If your institution would also like to receive the same Weekly Pick from us for display (usually in Photoshop or QuickTime format), please send your inquiry to steele.hill@gsfc.nasa.gov.

\
 
 

• European Site • US Site

 

Feedback & Comments: SOHO Webmaster

Last modification:

SOHO
and
SOHO
SOHO is a project of international cooperation between