REPORT FROM ISAS
                        20-Feb-94 to 26-Feb-94
                              L. W. Acton

This past week there has been a lovely pair of active regions, with plenty
of loop activity but little or no impulsive flare activity, crossing the
disk.  One M-flare began during Yohkoh night but we should have observed
the SXR peak and decline in the DSN data which I haven't yet seen.  There
was a data transfer problem between JPL and ISAS that began at an
unfortunate time for prompt local response so a 54-contact backlog was
created at JPL that may have to be transferred on tape.  This may in turn
put the Yohkoh reformatting somewhat behind.

It was a quiet week at ISAS because most of the key people were attending a
Solar-B workshop at NAOJ.  This local scientific discussion, in Japanese,
of the objectives and configuration of the next Japanese solar mission is
preparatory to an international meeting on the same subject planned for
this summer.  As always, the practical boundary conditions and the
spatial/spectral/temporal instrumental trade-offs are challenging and
painful.  It is gratifying to see the number of sharp young Japanese
scientists deeply involved in this process.

With the decrease in solar activity we are increasingly interested in deep
SXT exposures.  The question is, how deep can we go before coronal changes,
solar rotation and instrumental artifacts become the limiting factor.  This
week I have been working with summed one minute full resolution exposures
of the south half of the disk obtained in support of a ground-based
observing campaign by Shadia Habbal at CFA and Madhulika Guhathakurta at
GSFC.  The statisical quality of the 240 second sums is exquisite and
reveal instrumental artifacts in AlMg, a near horizontal set of lines
across the brighter portions of the image, which I've never seen before. 
It is not yet clear to me whether these extremely deep exposures reveal
more about the solar corona than somewhat shorter exposures--we may be up
against the limit of our ability to correct for artifacts.  Stay tuned for
further reports. 

I've done some more work on the "specks" that appear on the visible light
diffuser image.  An image has been put on-line in SHOW_PIX.  While it is
true that the specks are pretty much only on regions on the CCD covered by
the solar image their distribution is not consistent with being burned-in
images of flare kernels--which was my original interpretation.  What can
they be??   How much time should a fellow take away from solar research to
try to figure out the answer??   I've GOT to get my AGU abstracts prepared. 

Gary Linford has now managed, after enormous travail, to install the new
operating system on isass3 and isass4.