SXT Status Report
                     July 5 through July 18, 1999
                            (Weeks 28-29)
 
                        B. Handy, H. Hudson


SUMMARY

We began the current reporting period with high solar activity.  This
level of activity was not to hold, though, and at the end of the
reporting period the GOES database shows baseline activity approaching
solar minumum levels.  We anticipate the active regions coming over the
limb will bring the x-ray flux back into par.  The sun still produced
numerous interesting events, including the M-class flare co-observed
with TRACE, transequatorial loops, a giant polar crown filament near
the south pole and the birth of a CME off the west limb.

SOLAR ACTIVITY

In the last reporting period we reported being near solar maximum, 
but the GOES background levels at the end of the reporting period have
deteriorated from about C2 to near B3.  We surmise this will turn
around as active regions return to the visible side of the solar disk,
with one large one currently coming over the NE limb.  Yohkoh observed
one M-class flare that was simultaneously observed by TRACE.  The HXT
data shows a very soft spectrum for this flare, strange for such a
strong flare.

OBSERVING CAMPAIGNS

This was a quiet period from a campaign standpoint, with no active
campaigns taking place.  The serendipitous flare observation with
TRACE is the only recorded activity during this time.  

SXT INSTRUMENT STATUS AND CALIBRATION ACTIVITIES

Yohkoh repointed on July 2, beginning a new epoch of terminator
aquisition for the stray-light database.  This is now in full
swing and it is apparent we made the pointing change at the point in
the season when the solar radius was at a minimum.  (So why is Japan
so warm right now?)

No tables were uploaded 11-July through 13-July while the ISAS
mainframe was down for replacement.

CCD bakeout will take place next week.

SXT OBSERVING SEQUENCE TABLES

     --------------------------------------------------------
       JST Day/UT Day     Pass   Table ID
     ========================================================
       Mon   5-JUL-99     2      990705 P2 ARS1 STANDARD 
       Tue   6-JUL-99     3      990706 P3 ARS1 DARK 
       Wed   7-JUL-99     3      990707 P3 ARS1 DIFFUSER 
       Thu   8-JUL-99     2      990708 P2 ARS1 STANDARD
       Fri   9-JUL-99     3      990709 P3 ARS1 STANDARD 
       Sat  10-JUL-99     3      990710 P3 ARS1 STANDARD 
       Wed  14-JUL-99     2      990714 P2 ARS1 DARK
       Thu  15-JUL-99     2      990715 P2 ARS1 DIFFUSER
       Fri  16-JUL-99     2      990716 P2 ARS1 STANDARD 
       Sat  17-JUL-99     3      990717 P3 ARS1 STANDARD 
     =======================================================


SCIENCE

Weekly science nuggets were:
      
            9-Jul-99:  Transequatorial loops and magnetic reconnection
           16-Jul-99:  X-ray eclipse preview

The full list of nuggets is kept on
  http://isass1.solar.isas.ac.jp/sxt_co/index.html , 

and the current week's nugget also normally resides on
  http://isass1.solar.isas.ac.jp/sxt_co/SXTweekly.html .


SEMINARS

There were no seminars during the reporting period.


YOHKOH OPERATIONS ISSUES

The mainframe computers at ISAS were replaced during the interval
11-July (Sun) to 14-July (Wed).  A standard table was run continuously
during this period, and we were back in full operation on 14-July, 
a day ahead of schedule.  The system appears to be working fine.

VISITORS AND PERSONNEL

Brian Handy remains at ISAS, Bob Bentley and Greg Slater departed.

TOHBANS (spacecraft operators)

Tohbans for week 27

  SSOC:   K. Aoki, T. Shimizu
  KSC:    H. Tanooka, S. Yashiro
  SXT_CO: B. Handy
  SXT_SW: G. Slater

Tohbans for week 28

  SSOC:   A. Sakao, T. Watanabe
  KSC:    T. Magara, H. Tanooka
  SXT_CO: B. Handy
  SXT_SW: G. Slater