18 May 1998 David McKenzie Hugh Hudson SXT CHIEF OBSERVER'S REPORT AND TABLE PLAN CHIEF OBSERVER'S REPORT for Week 20 11-May-98 to 18-May-98 SOLAR ACTIVITY Solar activity was moderate, with three M flares, but definitely was reduced by comparison with the previous week. The huge filament complex in the S rotated beyond the W limb, and as of May 16 had defied all predictions and not erupted. SXT INSTRUMENT STATUS SXT has been working fine. The Chief Observers feel that another update of the normal pointing definition is in order (we also did one last week). It is a bit unusual to have to do another so soon, but it may be routine. We request an OP+OG for Tuesday, plus an ROG #32 (decimal). 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 In this week's webpage we describe the remarkable three-spacecraft joint observations that took place as part of SOHO JOP 059 and JOP 080. CAMPAIGNS This week SXT took part in two Joint Observing Programs (JOPs). Both of these emphasized microflares and time-series analysis. Things worked very well for SXT in that we got the (fixed) exposures right, and also put the FOV exactly where and when the other spacecraft were observing. A good experience all around from the operations point of view, and the data look extremely good (some nice examples of loop-filling flows, for example, which will be extremely interesting to see with low-temperature data from TRACE and SOHO; also there were tiny "three-legged flares" on the Nobeyama model). PERSONNEL No personnel changes this week. SEMINARS No seminar this week, deferring to a SOLAR-B exercise. SXT TABLE PLAN FOR WEEK 98_21 (18-May-98 - 24-May-98) SXT Chief Observer: McKenzie There are no formal joint observing campaigns this week, but we will try to follow TRACE and SOHO if possible. We also intend to get special dark exposures to test the linearity of the exposure-time relationship. ________________________________#_______________________________ JST Day UT Start Time Pass Table ID Monday 18-MAY-98 10:04 1 980518 P1 ARS1 STD Tuesday 19-MAY-98 13:45 3 980519 P3 DARK SPECIAL Wednesday 20-May-98 12:20 2 980520 P2 ARS1 STD+DIF Thursday 21-May-98 10:55 2 980521 P2 ARS1 STD Friday 22-May-98 11:13 2 980522 P2 ARS1 STD Saturday 23-MAY-98 09:49 2 980523 P2 ARS1 STD Monday 25-MAY-98 10:24 2 980525 P2 ARS1 STD * * This is a tentative assignment. 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). 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.