February 8, 1999 
                                                               Hugh Hudson  


              SXT CHIEF OBSERVER'S REPORT AND TABLE PLAN

                CHIEF OBSERVER'S REPORT for Week 06
                        31-Jan-99 to 7-Feb-99

GENERAL

SXT continues to perform properly, except for the new rupture (see
below) and one day's rest resulting from a poorly timed SEU.  Solar
activity was as low as it has been during this maximum, although there
was abundant evidence of high activity on the invisible hemisphere (a
C5 LDE on Feb. 4, at which time the major spot group, 8446, was about
two days beyond the W limb).

SXT TECHNICAL

SXT lost another piece of its entrance filter, resulting in another
increment of the stray-light level. The software is still recovering
and we've taken Al.1 out of the movie sequence in the meanwhile.

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/990205.html
Index:        http://www.solar.isas.ac.jp/sxt_co/index.html

The current Nugget discusses the MHD of arcade flare morphology,
plus the observability of preflare brightening, using a flare of
Dec. 23, 1998, as an example.

CAMPAIGNS

We've been running in support of an ill-starred flare campaign
at Sac Peak. We hope they get something this week! Meanwhile,
SOHO has started up again, and we have a future joint observation
of active regions scheduled with SUMER.

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

PERSONNEL

Loren Acton arrived for a month's visit.

SEMINARS

D. McKenzie (MSU) "Arcade Formation During the 20-Jan-99 Slow LDE Flare"
H. Hudson (SPRC) "Reconnection at Streamer Cusps?" (journal review)





                      SXT TABLE PLAN, WEEK 7
                     (8-Feb-99  to 14-Feb-99)


The Sac Peak campaign led by Gianna Cauzzi will continue through
the beginning of this week (through Feb. 12 and maybe longer -
we will encourage them to continue if they can, because they
have had very bad luck thus far with weather, space instruments,
and solar activity).


________________________________#_______________________________

JST Day         UT Start Time      Pass    Table ID

Monday           8-FEB-99 04:57    1      990208 P1 ARS1 TERM
Monday           8-FEB-99 06:39    2      990208 P2 ARS2 STD
Tuesday          9-FEB-99 05:12    2      990209 P2 ARS2 DARKCAL 
Wednesday       10-FEB-99 05:28    2      990210 P2 ARS2 DIFF
Thursday        11-FEB-99 04:02    2      990211 P2 ARS2 STD
Friday          12-FEB-99 04:18    2      990112 P2 ARS2 STD
Saturday        13-FEB-99 04:34    2      990113 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.