28 August 1998 Hugh Hudson SXT CHIEF OBSERVER'S REPORT AND TABLE PLAN CHIEF OBSERVER'S REPORT for Week 35 24-Aug-98 to 28-Aug-98 SOLAR ACTIVITY The level of solar activity picked up considerably with the appearance of AR8307 which produced several M- and X-class flares. Many of these occurred during Yohkoh day and one, in particular, was detected during a real-time contact. The Whole Sun Fortnight (WSF) campaign concluded. The was solar eclipse on 21/22-Aug-98 was successfully observed, and the latter two episodes were put into this week's science nugget. As of the time of writing the Madrid pass containing the first two episodes had not appeared, and there is an ominous foreboding about the possibility of a complete loss of these data. SXT INSTRUMENT STATUS SXT has been working fine, but there was a further safehold necessitating an SXT HALT command. The final recovery from this was completed Aug. 27 and normal operations resumed. After the safehold occurrence, H. Hara wrote a special table with flare mode disabled. This is a good practice in case of poor pointing. The FFIs were doing dark cals, also a good practice in case of poor pointing! SXT SCIENCE For Web material see Current Week: ftp://isass0.solar.isas.ac.jp/pub/sxt_co/SXTweekly.html Index: ftp://isass0.solar.isas.ac.jp/pub/sxt_co/index.html The science nugget (week 98_35) shows the eclipses. CAMPAIGNS The conclusion of the Whole Sun Fortnight was a bit inglorious because of the safehold interruptions. There were no other campaign activities during the week. PERSONNEL David Alexander returned to the US. Nariaki Nitta arrived. TABLE PLAN, WEEK 36 (31-Aug-98 - 6-Sep-98) SXT Chief Observer: Hudson There are no formal campaigns planned for this week, but we will as usual keep an eye on TRACE targets if possible. ________________________________#_______________________________ JST Day UT Start Time Pass Table ID Monday 31-AUG-98 10:36 2 980831 P2 ARS1 STD Tuesday 1-SEP-98 09:11 2 980901 P2 ARS1 STD Wednesday 2-SEP-98 09:28 2 980902 P2 ARS1 STD DIF Thursday 3-SEP-98 11:29 4 980903 P4 ARS1 DARKCAL Friday 4-SEP-98 08:20 2 980904 P2 ARS1 STD Note that this plan may change during the week. 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.