16 February 1998
                                                              HSH, DMCK 
  

              SXT CHIEF OBSERVER'S REPORT AND TABLE PLAN

                 CHIEF OBSERVER'S REPORT for Week 7 
                       9-Feb-98 to 14-Feb-98


SOLAR ACTIVITY

Solar activity was somewhat higher than last week, but the GOES 1-8 A flux
did not reach C class - in spite of many smaller events - until Feb. 15.  
AR 8156 had reached an area of 500 millionths as of Feb. 14,  and was
quite visible on the museum images, complete with leader spot,
followers, etc.


SXT INSTRUMENT STATUS

The recovery from the filter rupture of Jan. 24 is almost complete.
The Al.1 images look better than before, probably because we have
now learned (LWA's discovery) that the TIME of the Al.1 terminator
image is important because of apparent solar radius changes. The
new terminators are of course all at about the right time.

SXT recommends that the "normal pointing" be updated more frequently
during the new stray-light era. Hudson will improve the software to
make it possible for this to be done conveniently.

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" describes expanding (?) active-region loops,
a lucky observation obtained in coordination with a CDS search for the
same effect (Per Maltby and others). There is also some information about
next week's eclipse - predictions from Soma_san for the lunar trajectory
in Yohkoh-centric coordinates.

CAMPAIGNS

There was no official campaign, but we observed AR 8151 to support
CDS.  We observed expanding loops in this S-shaped region.


PERSONNEL

N. Nitta returned to California.  D. McKenzie and H. Hudson arrived. 

SEMINAR

There were no seminars this week.



                   SXT TABLE PLAN FOR WEEK 98_08 
                      (16-Feb-98 - 21-Feb-98)

SXT Chief Observer: McKenzie/Hudson 

There are no planned campaigns this week, so we will try to prepare
ourselves for the eclipse.  An "eclipse practice run" is scheduled
for Friday.  A CCD bakeout is planned for Wednesday and Thursday.  

________________________________#_______________________________

JST Day     UT Start Time      Pass    Table ID

Monday      16-FEB-98 09:35     3      980216 P3 ARS1 STD+DIFF 
Tuesday     17-FEB-98 09:53     3      980217 P3 ARS1 DARKCAL
Wednesday   18-FEB-98 06:45     2      980218 P2 ARS1 BAKE0UT (start)
Thursday    19-FEB-98 07:03     2      980219 P2 ARS1 STD (bakeout end)
Friday      20-FEB-98 05:38     2      980220 P2 ARS0 ECLIPSE 
Friday      20-FEB-98 07:21     3      980220 P3 ARS1 STD 
Saturday    21-FEB-98 09:23     4      980221 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).