Filament Cavities

Filament cavities observed with Yohkoh/SXT.

Filament cavities are a void structure appeared on the limb. They are often observed with a core located at the center; so this structure is sometimes called by the nickname 'chewy nougat'. They are thought to be the X-ray counterpart of the filament (or prominence) cavity observed in the optical (white light) observations. For more description, see this article in our Weekly Science Nuggets, or the paper, Hudson, et al. (1999). Some more images from : HAO(S.Gibbson) and XRT(K.Reeves).

1. Long lasting cavity, Jun to August, 1997 (observed at least for 2.5 rotations).

A snap shot of each limb passage : click image to enlarge.
(1) (2) (3) (4) (5) (6) (7) (8)

days observed limb full Sun images
(1) 24-May to 26-May-1997 SE movie
(2) 6-Jun to 7-Jun-1997 SW movie
(3) 20-Jun to 21-Jun-1997 SE movie
(4) 02-Jul to 04-Jul-1997 SW movie
(5) 17-Jul to 19-Jul-1997 SE movie
(6) 01-Aug to 02-Aug-1997 SW movie
(7) 16-Aug to 18-Aug-1997 SE movie
(8) 31-Aug to 1-Sep-1997 SW movie

2. Long lasting cavity, September to December, 1999.

(-16) (-15) (-14) (-13) (-12) (-11) (-10) (-9)
(-8) (-7) (-6) (-5) (-4) (-3) (-2) (-1)
(0) (1) (2) (3) (4) (5) (6) (7)
(8) (9) (10) (11) (12) (13) (14) (15)

days observed limb full Sun images
(-16) 04-Jan to 06-Jan-1999 SE movie
(-15) 19-Jan to 21-Jan-1999 SW movie
(-14) 05-Mar to 07-Feb-1999 SE movie
(-13) 19-Mar to 22-Feb-1999 SW movie
(-12) 05-Mar to 07-Mar-1999 SE movie
(-11) 18-Mar to 20-Mar-1999 SW movie
(-10) 04-Apr to 06-Apr-1999 SE movie
(-9) 18-Apr to 20-Apr-1999 SW movie
(-8) 03-May to 05-May-1999 SE movie
(-7) 19-May to 20-May-1999 SW movie
(-6) 02-Jun to 04-Jun-1999 SE movie
(-5) 19-Jun to 21-Jun-1999 SW movie
(-4) 02-Jul to 02-Jul-1999 SW movie
(-3) 17-Jul to 19-Jul-1999 SW movie
(-2) 05-Aug to 07-Aug-1999 SE movie
(-1) 20-Aug to 21-Aug-1999 SW movie
(0) 31-Aug to 2-Sep-1999 SE movie
(1) 6-Sep to 8-Sep-1999 SE movie
(2) 15-Sep to 22-Sep-1999 SW movie
(3) 30-Sep to 2-Oct-1999 SE movie
(4) 06-Oct to 08-Oct-1999 SE movie
(5) 19-Oct to 21-Oct-1999 SW movie
(6) 2-Nov to 4-Nov-1999 SE movie
(7) 08-Nov to 11-Nov-1999 SE movie
(8) 13-Nov to 16-Nov-1999 SW movie
(9) 04-Dec to 06-Dec-1999 SE movie
(10) 19-Dec to 21-Dec-1999 SW movie

3. Other likely events (not persistent, less than half rotation).

Snap shots : click image to enlarge.
(1) (2) (3) (4) (5) (6) (7)

days observed limb full Sun images
(1) 10-Jan to 12-Jan-1992 NE movie
(2) 28-Apr to 29-Apr-1995 NE movie
(3) 28-Apr to 30-Apr-1996 SE movie
(4) 30-Jan to 31-Jan-1997 SE movie
(5) 25-Sep to 26-Sep-1997 NW movie
(6) 07-Oct to 08-Oct-1998 NW movie
(7) 15-Jun to 18-Jun-2000 NE movie (erruption seen 18-Jun 20:30)

4. Dual Cavities (just for fun).

[ Example in 1998 ]

(1-a) 15-Sep-1998    full sun movies (1-b) 27-Sep-1998    full sun movies
(2-a) 13-Oct-1998    full sun movies (2-b) 26-Oct-1998    full sun movies
(3-a) 12-Nov-1998    full sun movies (3-b) 28-Nov-1998    full sun movies
(4-a) 11-Dec-1998    full sun movies (4-b) 25-Dec-1998    full sun movies
(5-a) 10-Jan-1999    full sun movies (5-b) 25-Jan-1999    full sun movies

[ Another example in 2000 ]

(1-a) 16-Feb-2000    full sun movies (1-b) 04-Mar-2000    full sun movies
(2-a) 16-Mar-2000    full sun movies (2-b) 31-Mar-2000    full sun movies
(5-a) 13-Apr-2000    full sun movies (5-b) 01-May-2000    full sun movies

SXT intensity with KittPeak magnetic field synoptic map is here.