21 February 1998
                                                                   DMCK 
  

              SXT CHIEF OBSERVER'S REPORT AND TABLE PLAN

                 CHIEF OBSERVER'S REPORT for Week 8 
                      16-Feb-98 to 21-Feb-98


SOLAR ACTIVITY

Solar activity was only slightly higher than last week.  The GOES
background level remained in the mid-B range, but the Sun did produce a
number of C flares, mostly from region AR 8156. 


SXT INSTRUMENT STATUS

The recovery from the filter rupture of Jan. 24 is almost complete.
We continue to make terminator images to help compensate for the
extra light; we now have terminators in four different filter 
configurations. 
	We performed a bakeout of the CCD this week, on Wednesday and
Thursday.  All indications are that the bakeout was successful and the 
instrument is performing well.

SXT SCIENCE 

For Web material see

Weekly: ftp://isass0.solar.isas.ac.jp/pub/sxt_co/SXTweekly.html
Index:  ftp://isass0.solar.isas.ac.jp/pub/sxt_co/index.html
1997:   ftp://isass0.solar.isas.ac.jp/pub/yohkoh_in_1997/1997.html

This week's "science nugget" contains some updates in the plans for
our eclipse observations.  

CAMPAIGNS

After this week's CCD bakeout, we uploaded an SXT table to simulate
the observations planned for next week's eclipse.  This "practice run"
gave us the chance to test the planned SXT Table, and make the 
application of this table go more smoothly.

PERSONNEL

H. Hudson departed at the end of the week; he will return
after next week. 

SEMINAR

The seminar this week was presented by J. Sato, of Nobeyama Observatory.
Sato described improvements in Yohkoh hard X-ray imaging, primarily
through enhancements to the maximum-entropy method of data reduction 
to include consideration of the modulation pattern of the detectors.



                   SXT TABLE PLAN FOR WEEK 98_09 
                      (23-Feb-98 - 28-Feb-98)

SXT Chief Observer: McKenzie 

There will be a solar eclipse this week, during the JST Thursday
night-time.  SXT will upload a table of special observations on 
Thursday afternoon.

________________________________#_______________________________

JST Day     UT Start Time      Pass    Table ID

Monday      23-FEB-98 06:33     3      980223 P3 ARS1 STD 
Tuesday     24-FEB-98 05:08     3      980224 P3 ARS1 STD+DIFF
Wednesday   25-FEB-98 05:26     3      980225 P3 ARS1 STD   
Thursday    26-FEB-98 07:27     4      980226 P4 ARS0 ECLIPSE
Friday      27-FEB-98 02:36     2      980227 P2 ARS1 DARKCAL 
Friday      27-FEB-98 06:02     4      980227 P4 ARS1 STD 
Saturday    28-FEB-98 06:20     4      980228 P4 ARS1 STD    

Note that this plan is subject to change. 


Continuing requests:

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 & 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).