March 6, 1999 
                                                               Hugh Hudson  


              SXT CHIEF OBSERVER'S REPORT AND TABLE PLAN

                 CHIEF OBSERVER'S REPORT for Week 10
                       2-Mar-99 to 8-Mar-99

GENERAL

SXT continues to perform properly. Terminator acquisition has been slow.
Solar activity continued at a moderate level, with one noteworthy M flare
written up in the weekly science nugget. 

SXT TECHNICAL

No news.

SXT SCIENCE

For Web material see

Current Week: http://www.solar.isas.ac.jp/sxt_co/SXTweekly.html
Current Week: http://www.solar.isas.ac.jp/sxt_co/990305html
Index:        http://www.solar.isas.ac.jp/sxt_co/index.html

The current Nugget shows signatures of helicity related to the M-class
flare of Feb. 28, which as already attracted two pieces of fan-mail.

CAMPAIGNS

There were no coordinated observations during hte week. In week 11,
we are cooperating with SOHO JOP98 (Ranns) and TRACE and intend to
do mostly ARS2 pointing.

Please see the general coordination page at:
http://sec.noaa.gov/solcoord/solcoord.html

For SXT plans, finger campaign@isass0.solar.isas.ac.jp.

PERSONNEL

Acton departed, having made a lot of progress with SXT entrance-filter
behavior. He is no longer so sure of the micrometeorite theory.


SEMINARS

J. Sato (NRO) "Spatially resolved hard X-ray spectra"

T. Naito (NAO) "Particle acceleration in a shock wave at the 
                impulsive phase of a solar flare"

The speculation is that a fast shock accelerates the non-thermal
electrons, and that the Petschek slow shocks help to trap them in 
the corona.




                      SXT TABLE PLAN, WEEK 11
                      (7-Mar-99 to 13-Mar-99)


There will be an effort to characterize preflare activity, coordinated
with CDS and TRACE via JOP98. This will require ARS2 pointings, so
we may want to do two tables per day. The idea now is to leave Be in
the sequence (cf. this week's science nugget). 

________________________________#_______________________________

JST Day         UT Start Time      Pass    Table ID

Monday          7-MAR-99 17:33     2      990307 P2 ARS1 STD (*) 
Tuesday         8-MAR-99 14:24     1      990308 P1 ARS2 STD (*) 
Tuesday         8-MAR-99 21:15     5      990308 P5 ARS2 DAR (*) 
Wednesday       9-MAR-99 16:22     2      990309 P2 ARS2 DIF (*)
Thursday       10-MAR-99 14:55     2      990310 P2 ARS2 STD 
Thursday       10-MAR-99 16:38     3      990310 P3 ARS2 STD (*)
Friday         11-MAR-99 15:11     2      990311 P2 ARS2 STD (*)
Friday         11-MAR-99 20:20     5      990311 P5 ARS2 STD (*)
Saturday       12-MAR-99 15:26     3      990312 P3 ARS2 STD (*)
Sunday         13-MAR-99 13:59     2      990313 P2 ARS1 STD

(*) => table name adopts the convention of UT date of first pass,
so that the UT day and JST day for that pass don't match.

Continuing requests:

KSC & SSOC Tohbans: If any KSC passes are likely to be cancelled (for
example due to a typhoon) or an SXT table cannot be uploaded for some
reason, please telephone and e-mail the Chief Observer immediately.
(sxt_co@isass0.solar.isas.ac.jp, copy to sxt_st@flare2.solar.isas.ac.jp).

SSOC Tohban: On the weekly visible diagram, please mark the official
five passes first and then cross out those passes that will be given to
other satellites.  That way we can keep the numbering straight in the
Yohkoh software system.

SSOC Tohban: SXT operations do not currently include terminator off-
pointing. It is unnecessary this week to ask the SXT Chief Observer
for terminator off-pointing information.

KSC Tohbans: In general flare mode supersedes table upload, ie if a
flare is in progress please do not upload a new table, and contact the
chief observer. Normally it is OK to go ahead with the planned table
without change on the next pass, if it is available. Chief observers
should keep an eye on this.