Disappearing Filament Inside a Coronal Hole
and Associated Activity
 

I.M. Chertok(1), H.S. Hudson(2), E.I. Mogilevsky(1), V.N. Obridko(1), and N.S. Shilova(1)

(1) IZMIRAN, Troitsk, Moscow Region, Russia
(2) Solar Physics Research Corporation, ISAS,  Sagamihara, Japan

Introduction


Usually:

CHs are large-scale areas of relatively cool, low density and emission plasma with open, predominantly unipolar magnetic fields and without significant inside activity (e.g., Zirker, 1977;  K. Harvey, 1995; Mogilevsky et al., 1997; Obridko and Shelting, 1999; Zhao et al., 1999).


       Small-scale bright points (see Davis, 1985; Kahler and Moses, 1990; K.Harvey, 1995).
 

Sometimes --  medium-scale features in CHs:

This report  --   the December 28-29, 1999 event with two peculiarities:
Yohkoh/SXT

H-alpha and Yohkoh/SXT


Data:


                  SOHO/EIT,  Yohkoh/SXT -- negative (inverted) images;
                  He 10830 ┼,  H-alpha,  SOHO/LASCO -- positive (normal) images


On location of the filament
H-alpha and Yohkoh/SXT
       He I, 10830 A

        Comparison of the CH at He I, 10830 A with SOHO/EIT 284 A and Yohkoh/SXT images

        Open magnetic field lines on the synoptic map

        Open magnetic field lines and filament on the sphere

      Quasi-separatrix layers on the synoptic map

        Calculated magnetic data (combined; Figure 2)


Preceding activity
SOHO/EIT, 195 A (10-22 UT) (Figure 3)

  SOHO/EIT, 195 A (difference to 20:12 UT)

SOHO/EIT, 171 A (Figure 4)

       MLSO/HAO H-alpha and He I 10830 A (Figure 5)
MLSO/HAO, He I 10830 A

MLSO, H-alpha

       Yohkoh/SXT


Eruption
SOHO/EIT, 195 A (28d,22:36-29d, 01:48 UT (Figure 7)

 SOHO/EIT, 195 A (difference to 22:24 UT) (Figure 8)

  SOHO/EIT, 195 A (difference to 22:24 UT)

Yohkoh/SXT

MLSO and Mitaka H-alpha

Yohkoh/SXT

SOHO/EIT, 195 A

SOHO/EIT, 171 A
 


Accompanying activity


      SOHO/LASCO/C2 (Figure 9)

SOHO/LASCO/C2

SOHO/LASCO/C3

Yohkoh/SXT

SOHO/EIT, 171 A (Figure 4)

        SOHO/EIT (171, 195, 284, 304 A)
Dec 29, 1999 (Figure 10)




      Renewed Figures

      SOHO/EIT, 195 A (09:12-18:24 UT) (Figure 3)

     SOHO/EIT, 171 A (Figure 4)

     MLSO/HAO H-alpha and He I 10830 A (Figure 5)

     SOHO/EIT, 195 A (difference to 22:24 UT) (Figure 8)
 


Conclusion

   Compressed POSTSCRIPT file of the paper accepted at "Astrophys. J."

       paper_ps.zip  (3.3 MB)