June 11, 1999 
                                                             Hugh Hudson 
 
                 CHIEF OBSERVER'S REPORT for Week 24
                       7-Jun-99 to 13-Jun-99

GENERAL

Activity was moderately high, but no flares have been registered. Two
large active regions are just appearing on the NE and SE limb, promising
more activity for next week's first Max Millennium flare campaign.

SXT TECHNICAL 

No major problems. Three offpoints have been performed for an observing
campaign. A slight increase in straylight, probably due to the offpoints,
has disappeared again. Dark current has increased ever so slightly over
the last two weeks, but may be stabilizing.

SXT SCIENCE

For Web material see

Current Week: http://www.solar.isas.ac.jp/sxt_co/SXTweekly.html
Current Week: http://www.solar.isas.ac.jp/sxt_co/990611.html
Index:        http://www.solar.isas.ac.jp/sxt_co/index.html

This week's science nugget shows long exposure streamer data from the
offpoint, demonstrating some X-ray emission up to half a Solar radius
above the limb. These data will be used for temperature and density
measurements.

CAMPAIGNS

There have been joint streamer observations with UVCS, SUMER, CDS,
TRACE, and ground based observatories, requiring three offpoints.

For more information on campaigns, see:

http://sec.noaa.gov/solcoord/solcoord.html

For SXT plans, finger campaign@isass0.solar.isas.ac.jp.

PERSONNEL

Piet Martens has arrived. He will be Chief Observer for the next 
two or three weeks.

SEMINARS

No seminar last week because of Solar-B meetings. This week Piet
Martens will give a seminar on "The Nature of Moss".

                               
                      SXT TABLE PLAN, WEEK 25
                      (13-Jun-99 to 18-Jun-99)

The two week Max Millennium flare campaign will start on Tuesday,
June 15. On Monday we will follow the brightest region with ARS1,
which will be our default for the campaign. However, we keep open
the option to shift to a target designated by the campaign
coordinators in various subsequent table uploads.

________________________________#_______________________________

JST Day         UT Start Time      Pass   Table ID

Monday          13-JUN-99 17:24    2      950613 P2 ARS1 STMAX01-1*
Tuesday         14-JUN-99 17:39    2      950614 P2 ARS2 DAMAX01-2*
Wednesday       15-JUN-99 19:36    3      950615 P3 ARS2 DIMAX01-2* 
Thursday        16-JUN-99 16:26    2      950616 P2 ARS2 STMAX01-2*
Friday          17-JUN-99 18:23    3      960617 P3 ARS2 STMAX01-2* 
Saturday        18-JUN-99 15:13    2      960618 P2 ARS1 STMAX01-1* 

"MAX01" stand s for first Max Millennium campaign, the extensions
-1 and -2 stand for the ARS1 and ARS2 modes.

As previously, the (*) in a table name means that the UT date and
the JST date don't match. 

This plan is subject to change.

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).

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 Tohbans: In general flare mode supersedes table upload, ie 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.