REPORT FROM ISAS
                        15-Feb-94 to 19-Feb-94
                              L. W. Acton

Yohkoh operations continue with solar GOES flux level in the mid B range
and occasional flares, mostly gradual, reaching the C1 level.  The only
flare flag was false but it gave me a chance to find a couple of
inadequacies in my X-ray neutral-density filter calibration table. 
Active regions 7669, 7670 and 7671 have moved to the central meridian
with very interesting loop activity but very little flaring.  This is a
large complex and will be useful for study of coronal heating in and
around regions of little flare activity.

Some nice happenings this week were the award of an SPD studentship to
Brian Handy of Montana State to supprt attendance at the Baltimore
meeting (yea, Brian!) and invitations to Kosugi and Acton to give
invited talks there.  Also, Masuda san and Sakao san both passed their
PhD examinations based upon HXT analysis.  Three cheers for the HXT team
for 3 doctorates from that experiment since Yohkoh launch.  A downer was
the several very long days Gary Linford put into unsuccessfully trying
to get the latest Unix System installed on ISASS4 (thanks, Gary). 

Extra effort went into getting deep SXT exposures of the sun's south
pole in support of Ulysses and some ground based observing.  The summed
quarter resolution images are somewhat disappointing.  Background
subtraction difficulties associated with the large pixels to some degree
annul the gain in photon statistics.  I'm trying the same experiment
today (an 18' south offpoint of Yohkoh) with full resolution images to
compare the advantages/disadvantages of the 2 extremes in pixl size for
this type of observing. 

Hugh Hudson continues to work with the spectacular eruption/ejection of
21-Feb-92 (much like the 2-Dec-91 event studied by Tsuneta and Martens).
The magnetic field topology of these things is, of course, not so simple
at the old cartoons.  Better cartoons should result in better physics.
I've begun a bit of work with Hara san to look at the radiative loses
from different classes of coronal structures--with the objective of a
paper on this at the AGU in Baltimore.