8 February 1998
                                                          Nariaki Nitta 
  

              SXT CHIEF OBSERVER'S REPORT AND TABLE PLAN

                 CHIEF OBSERVER'S REPORT for Week 6 
                       2-Feb-98 to 8-Feb-98


SOLAR ACTIVITY

Solar activity was even lower than last week, with the GOES 1-8 A flux
never reaching the C level.  The soft X-ray flux was especially low 
on the morning of 6-Feb-98, after regions AR 8143, 8145 and 8146 rotated
behind the west limb.  We saw the emergence of at least two compact 
regions, AR 8150 and 8152.  There were several B-class flares, and their 
frequency increased towards the weekend, presumably due to the growth of 
AR 8152.


SXT INSTRUMENT STATUS

We noticed another entrance filter opening that had occurred early on
24-Jan-98.  See the top item in the calibration subdirectory of
SHOW_PIX.  The straylight level appears to have been stable since then.  We
are collecting terminator images to cope with the new era.  Otherwise,
SXT operations have been smooth without problems.


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" surveys the SXT data for two large-scale events
that occurred during the week.

CAMPAIGNS

There was no official campaign, but ran a special jet observing sequence
on Friday.  No success, as usual.


PERSONNEL

N. Nitta arrived for a one-week stay.  D. McKenzie and H. Hudson are
returning over the weekend.


SEMINAR

No seminar this week.



                   SXT TABLE PLAN FOR WEEK 98_07 
                      (2-Feb-98 - 9-Feb-98)

SXT Chief Observer: McKenzie/Hudson 

We do not know of any coordinated observations for week 98_07, so depending
on solar conditions, we may try the jet sequence again.  

________________________________#_______________________________

JST Day     UT Start Time      Pass    Table ID

Monday       9-FEB-98 10:55     2      980209 P2 ARS1 STD 
Tuesday     10-FEB-98 14:39     4      980210 P4 DARKCAL
Wednesday   11-FEB-98 09:48     2      980211 P2 JET
Wednesday   11-FEB-98 13:14     4      980211 P4 STD+DIF
Thursday    12-FEB-98 11:49     3      980212 P3 ARS1 STD
Friday      13-FEB-98 08:41     2      980213 P2 ARS2 STD
Saturday    14-FEB-98 08:59     2      980214 P2 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).