29 March 1998 Nariaki Nitta SXT CHIEF OBSERVER'S REPORT AND TABLE PLAN CHIEF OBSERVER'S REPORT for Week 13 23-Mar-98 to 29-Mar-98 SOLAR ACTIVITY Although the GOES background level showed a slight decline due to big complex AR 8179/8180 rotating behind the limb, solar activity remained quite high. During 22-27 March, we had one > C5 flare a day, either from AR 8185 (CMP on 27 March) or AR 8179/8180 at the southwest limb. Two of them occurred during Yohkoh day, but the non-KSC data have not arrived yet. Other four were largely subject to spacecraft night, but the one on 24 March was a long duration event and its morphological change was well observed. SXT INSTRUMENT STATUS SXT has been working without problems. The SXT CO of week 98_12 was concerned that the latitude spread of the ARs might exceed the SXT patrol capability. But this was not a problem during week 98_13, although in one patral image a region on the southwest limb was close to the border. Inclusion of DPE 2 leak-monitor image to the H rate table seems to be a good idea, and we will keep it. 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 CAMPAIGNS There were no formal campaigns this week. PERSONNEL Hudson left for Switzerland toward the end of week 98_12, but he will be at the WOM of week 98_14. Nitta arrived during week 98_13 for a one month stay. SEMINARS No seminars during the week. SXT TABLE PLAN FOR WEEK 98_14 (30-Mar-98 - 5-Apr-98) SXT Chief Observer: Nitta There are no special operations this week. This week's observations depend on how AR 8185 and the one on the easten limb (as of 29-Mar-98 18 UT) evolve. This is not predicable at the moment. If their activity decreases, there may be a chance of observing jets - the last week SoHO may be observing them (18-Mar-98 to 5-Apr-98). Note that this plan is subject to change. ________________________________#_______________________________ JST Day UT Start Time Pass Table ID Monday 30-MAR-98 13:58 3 980330 P3 ARS1 STD Tuesday 31-MAR-98 14:17 4 980331 P4 DARKCAL Wednesday 1-APR-98 12:51 3 980401 P3 ARS1 DIFF Thursday 2-APR-98 13:09 3 980402 P3 ARS0 JET Thursday 2-APR-98 16:37 5 980402 P5 ARS1 STD Friday 3-APR-98 10:01 2 980403 P2 ARS0 JET Friday 3-APR-98 13:38 4 980403 P4 ARS1 STD Saturday 4-APR-98 12:02 3 980404 P3 ARS1 STD 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.