CHIEF OBSERVER'S REPORT for Week 15
                       9-Apr-01 through 15-Apr-01 

                         H. Hudson, A. Takeda

GENERAL 

The third of this month's X-rated active regions, AR 9415, crosses the
west limb today (April 16). It was never so impressive as AR9393 but somehow 
managed more X-class flares, including three this week. The Sunday flare
was an X14.

SXT TECHNICAL 

We have begun to observe with a 2x2 flare mode, including fixed long exposures
in an attempt to see waves better. We will probably be adjusting its parameters
during the week.

The SXT record of Yohkoh pointing shows more scatter in recent months (see
http://isass1.solar.isas.ac.jp/sxt_co/quick/fids.html).

This week we plan to experiment with "maximal" PFIs.

SXT SCIENTIFIC

For Web material see the science nuggets:

Current Week: http://isass1.solar.isas.ac.jp/sxt_co/010413.html
Index:        http://isass1.solar.isas.ac.jp/sxt_co/index.html

This week's science nugget, "Beautiful coverage of a major flare,"
deals with the X2.0 of April 12, for which our coverage was great.
One interesting feature of this flare was a "tilting cusp" - early on 
it pointed SW, later on NW.

CAMPAIGNS 

We remain on the alert for sigmoids as a Target Of Opportunity.

For SXT plans, see:
http://isass1.solar.isas.ac.jp/sxt_co/sxt_future.html

For SXT completed campaigns, see:
http://isass1.solar.isas.ac.jp/sxt_co/sxt_catalog.html

PERSONNEL

No changes. 

SEMINARS

None this week.

v. 3, 17-Apr-01 17:02

                     SXT TABLE PLAN, WEEK 16
                   (16-Apr-01 through 21-Apr-01)


There are no scheduled campaigns, but we are keeping the
target-of-opportunity sigmoid campaign still in the background. 
This week we will continue to run the special flare table 
oriented towards waves.

________________________________#_______________________________

JST Day         UT Start Time      Pass   Table ID

Monday PM      16-APR-01 05:31     2      010416 P2 ARS1 STD W
Tuesday PM     17-APR-01 07:14     3      010417 P3 ARS1 STD W 
Wednesday PM   18-APR-01 03:52     1      010418 P1 ARS1 W DARK
Wednesday PM   18-APR-01 07:15     3      010418 P3 ARS1 W DIFF
Thursday PM    19-APR-01 07:15     3      010419 P3 ARS1 STD W
Friday PM      20-APR-01 03:53     2      010420 P2 ARS1 STD W
Saturday PM    21-APR-01 05:35     3      010421 P3 ARS1 STD W

The date part of a table ID reflects the UT date of pass 1.

A '*' means that the UT date of pass 1 differs from the JST date
of the pass in question 

This table plan is likely to change.  Prepare for last minute changes.

Continuing requests:

KSC & SSOC Tohbans: If any KSC passes are likely to be cancelled (for
example due to typhoons) or an SXT table cannot be uploaded for any 
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).

KSC Tohbans: In general flare mode supersedes table upload, i.e. 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.