March 21, 1999 
                                                               Hugh Hudson  
                 CHIEF OBSERVER'S REPORT for Week 12
                       15-Mar-99 to 21-Mar-99

GENERAL

SXT continues to perform properly. Terminator image acquisition proceeds. 
Solar activity increased to a higher level, with many M flares but no
X's. The weekly science nugget examines a rather beautiful cusp feature.

SXT TECHNICAL

The CO examined the stray-light change noted by several persons at the
time of the pointing update, March 12. It is still not clear whether or
not we suffered a further entrance-filter event, and analysis continues.

SXT SCIENCE

The big news this week, of course, remains the sigmoid spectacular Space
Science Update. The science behind this is the detectability of pre-CME
sigmoid signatures in active regions. There are several science nuggets on
this topic, or see http://solar.physics.montana.edu/press/ and
http://solar.physics.montana.edu/press/release.html
for fuller details.

For routine 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/990319.html
Index:        http://www.solar.isas.ac.jp/sxt_co/index.html

CAMPAIGNS

There were no formal campaigns this week, but we ran ARS2 a bit in
order to sharpen the match with TRACE targets.

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

Phil Shirts and Alisdair Davey arrived.

SEMINARS

None this week.


                      SXT TABLE PLAN, WEEK 13
                      (22-Mar-99 to 27-Mar-99)


There are no scheduled joint observing campaigns this week, so
we will just try to keep up with TRACE and CDS informally, as
usual.

________________________________#_______________________________

JST Day         UT Start Time      Pass    Table ID

Monday         22-MAR-99 12:56     4      990322 P4 ARS1 DAR 
Tuesday        23-MAR-99 13:11     4      990323 P4 ARS1 DIF
Wednesday      24-MAR-99 11:44     3      990324 P3 ARS1 STD
Thursday       25-MAR-99 10:17     3      990325 P3 ARS1 STD
Friday         26-MAR-99 08:51     2      990326 P2 ARS1 STD
Saturday       27-MAR-99 07:23     2      990327 P2 ARS1 STD


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.