6 December 1999
                                                           H.S. Hudson 
                                                           


 
                   CHIEF OBSERVER'S REPORT for Week 49
                         28-Nov-99 to 6-Dec-99


GENERAL 


Solar activity was low, we are assuming that this is a courteous Sun
prolonging Yohkoh's orbit lifetime for overlap with HESSI and SOLAR-B.
In contrast to last week, when _all_ of the regions were delta spots,
this week _none_ are. How can the Sun be so lopsided?

SXT TECHNICAL 

There were no problems during the week.

For Web material see

Current Week: http://isass1.solar.isas.ac.jp/sxt_co/991205.html
Index:        http://isass1.solar.isas.ac.jp/sxt_co/index.html

This week's science nugget deals with the question of how well ARS1
(brightest-region tracking) anticipates flare occurrence. 

CAMPAIGNS 

There were no organized campaigns this week.  We continued taking
higher-cadence quarter-resolution FFIs, but this week's plan is
to discontinue this while we assess the many images we've obtained.
On the other hand, there was a hint of a successful global wave
detection today (Dec. 5).  Flare mode continues with the modified
AEC offset scheme.

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
No seminar.




                       SXT TABLE PLAN, WEEK 50 
                       (5-Dec-99 to 11-Dec-99)


The FlareGenesis balloon has slipped from 9-Dec, so we will try to
squeeze in a bakeout this week. Yohkoh data will be used to choose
targets, so we will be looking closely at the data and generating daily
target messages through Max Millenium starting (for practice) on the
8th. In the meanwhile we will return to the standard FFI table but
continue the AEC-enabled overexposed PFI sequences in flare mode. If we
have a target and a balloon flight, we may go to ARS2 and track the
target.

YES! A CCD BAKEOUT! 

________________________________#_______________________________

JST Day         UT Start Time      Pass   Table ID

Tuesday   PM    7-DEC-99 07:50     3      991207 P3 ARS1 DARKCAL
Wednesday PM    8-DEC-99 04:38     1      991208 P1 ARS1 DIFF
Thursday  PM    9-DEC-99 06:33     3      991209 P3 ARS1 STD 
Friday    PM   10-DEC-99 05:03     1      991210 P1 BAKE 
Saturday  PM   11-DEC-99 05:15     3      991211 P3 ARS1 STD

The bakeout sequence, as before (July 21 approximately) should go as
follows:

11-Dec: pass 1 - special bakeout sequence table
        pass 2 - TEC off
        pass 3 - heater on
        pass 4 - contingency, we'll be watching the data

12-Dec  pass 1 - heater off
        pass 3 - TEC on, standard table
        pass 5 - contingency

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).

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.