February 28, 1999 
                                                               Hugh Hudson  


              SXT CHIEF OBSERVER'S REPORT AND TABLE PLAN

                 CHIEF OBSERVER'S REPORT for Week 9
                       23-Feb-99 to 1-Mar-99

GENERAL

SXT continues to perform properly, and there is nothing special to  report.
Solar activity continued at a low level. 

SXT TECHNICAL

Yohkoh executed another "normal pointing update,"  as we attempt to
get a proper set of Al.1 terminator images for stray-light correction.
In a "quick reformat" of data on Feb. 23, aiming at a science nugget,
the CO noticed many gaps in the images. This happens sometimes - can
it be repaired by re-transmission and re-copying into Sirius? On his
last visit, Greg Slater suggested that we routinely reformat new
acquisitions temporarily, and if we did that we might be able to catch
situations like this more easily.

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/990226html
Index:        http://www.solar.isas.ac.jp/sxt_co/index.html

The current Nugget shows a weak polar example of Ron Moore's Elbows.

CAMPAIGNS

There was a desultory attempt to look at the same target as the VLA
this week, a task made difficult by the fact that neither the VLA nor
our standard coordination Web page has chosen to report VLA targets.
Repeated e-mail reminders have also produced no results.

We also worked with TRACE in an attempt to find clean loops for a
Klimchuk analysis of loop geometry, Feb. 24 - perhaps not so successful,
it is quite difficult to find non-overlapping loops.

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

No changes.

SEMINARS

L. Acton (MSU): 1. "Conversion of SXT fluxes to irradiances"
                2. "Deriving solar X ray irradiance from Yohkoh
                    observations"



                      SXT TABLE PLAN, WEEK 10
                      (28-Feb-99 to 7-Mar-99)


There are no firm joint observing plans for this week, but we will
as usual keep an eye on TRACE or various SOHO plans for targets
of opportunity.

________________________________#_______________________________

JST Day         UT Start Time      Pass    Table ID

Tuesday         1-MAR-99 22:50     4      990301 P4 ARS1 DAR (*) 
Wednesday       2-MAR-99 19:40     2      990302 P2 ARS1 DIF (*)
Thursday        3-MAR-99 18:13     2      990303 P2 ARS1 STD (*)
Friday          4-MAR-99 18:29     2      990304 P2 ARS1 STD (*)
Saturday        5-MAR-99 17:02     2      990305 P2 ARS1 STD (*)

(*) => table name adopts the convention of UT date of first pass

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.