SXT Status Report
                      Jan. 1, 1998 - Jan. 19, 1998
                              (Weeks 1-3)

                  H. Hudson, L. Acton, S. Savy, M. Weber


SUMMARY

This is the first SXT status report from 1998.  There was an uneventful
New Year's "telemetry holiday"; SXT continues to operate well.  Solar
activity has had ups and downs during this period, including M flares.
For a look at some of the interesting scientific items from 1997,
please refer to

ftp://isass0.solar.isas.ac.jp/pub/yohkoh_in_1997/main.html,

or our regular weekly "science nuggets" listed at

ftp://isass0.solar.isas.ac.jp/pub/sxt_co/index.html.

SOLAR ACTIVITY

There were ~31 C-class flares during this interval (from 27-Dec), plus
4 M-class (note the "correct" distribution"!).  The background GOES
level dropped to A2 (see the science nugget for Jan. 10) in a rather
interesting manner, but then activity returned with a growth of AR8131
(see the science nugget for Jan. 17).

SXT INSTRUMENT STATUS AND CALIBRATION ACTIVITIES

Data archiving is complete through Week 50 (ending Dec. 13, 1997). 

There continue to be headaches in the handover from DSN to Wallops
for NASA telemetry scheduling. None of these problems are the fault
of Wallops or NASA in general, it is just that the Yohkoh operations
software has had a long stable period to be perfected and forgotten. We
expect that the transition woes will be finished by the end of January.
Unfortunately, we lost six dumps to Madrid as a result of clerical
errors in Week 2.

Dark and stray corrections are a theme this month as Acton visits. We hope
to be ready by the end of the month for the long-awaited re-do of the
Yohkoh SXT movie, with many new features put in place.

WEB-BASED SCIENCE REPORTS

The scheme of weekly reporting by the SXT Chief Observer on Web pages
has continued. The current "science nugget" is always at

ftp://isass0.solar.isas.ac.jp/pub/sxt_co/SXTweekly.html

which links to this report and other pages, the previous science
nuggets reported by SXT chief observers.

ftp://isass0.solar.isas.ac.jp/pub/sxt_co/971024.html  dimming
ftp://isass0.solar.isas.ac.jp/pub/sxt_co/971031.html  EIT Calroc
ftp://isass0.solar.isas.ac.jp/pub/sxt_co/971107.html  Nov 6 flare
ftp://isass0.solar.isas.ac.jp/pub/sxt_co/971114.html  Nov 14 LDE
ftp://isass0.solar.isas.ac.jp/pub/sxt_co/971121.html  Movies of ejecta!
ftp://isass0.solar.isas.ac.jp/pub/sxt_co/971128.html  X2.9 ejective flare
ftp://isass0.solar.isas.ac.jp/pub/sxt_co/971205.html  Solar cycle
ftp://isass0.solar.isas.ac.jp/pub/sxt_co/971215.html  Amazing arcade
ftp://isass0.solar.isas.ac.jp/pub/sxt_co/971221.html  AR development
ftp://isass0.solar.isas.ac.jp/pub/sxt_co/971228.html  Interconnection
ftp://isass0.solar.isas.ac.jp/pub/sxt_co/980110.html  Global time constant? 
ftp://isass0.solar.isas.ac.jp/pub/sxt_co/970117.html  Contrasting emergence 

The most recent entries deal with interesting features noted in the GOES
light curve, and explained (or not) by means of the SXT images.

PASS CONFLICTS AT KSC (Akebono, HALCA, ASCA)

Week 2: Five passes lost to HALCA, four to Akebono.
Week 3: Five passes lost to HALCA, one to Akebono, and 1 to maintenance.

CAMPAIGNS

There were no formal campaigns during these two weeks. 

For Yohkoh target planning, the SXT weekly observing plan is available
on the Web at

http://www.space.lockheed.com/SXT/html2/First_Light.html

or with

"finger campaign@isass0.solar.isas.ac.jp | more".

See http://sohowww.nascom.nasa.gov/operations/targets/today
for SoHO target planning.

VISITORS AND PERSONNEL

Weber returned from Wakayama with a black belt. Acton arrived from 
Montana, and visitor M. Sersen arrived from Bratislava. Both were in
time to see record-setting snowfall in Sagamihara - maybe 30 cm!

SEMINARS

There were no Yohkoh seminars during these weeks. The seminar
series will resume on Jan. 22 (series D of this long-running show!).

TOHBANS

Tohbans for Week 53

     SSOC: Y. Kato, T. Kosugi
     KSC : S. Masuda, J. Sato
     SXT_CO: H. Hudson
     SXT_SW: -

Tohbans for Week 2

     SSOC: Y. Iizuka, T.Watanabe
     KSC : M. Ohyama
     SXT_CO: H. Hudson
     SXT_SW: -

Tohbans for Week 3

     SSOC: J. Khan, S. Yashiro 
     KSC : M. Ohyama, K. Fujiki 
     SXT_CO: H. Hudson
     SXT_SW: -