19 September 1998 Hugh Hudson SXT CHIEF OBSERVER'S REPORT AND TABLE PLAN CHIEF OBSERVER'S REPORT for Week 38 13-Sep-98 to 20-Sep-98 GENERAL Yohkoh SXT has performed with no difficulty this week. There is virtually no technical news whatsoever. On the science side, the Sun became quieter but still managed to be quite interesting. Today's images show several noteworthy things: A small active region (NOAA 8337) at the amazingly high latitude of about S40; a huge set of interconnecting loops on the W limb linking N and S; and at disk center, a faint but strikingly developed sigmoid structure, of the general type that may erupt to form a halo CME. We would like to be able to predict these occurrences a bit better. SXT SCIENCE For Web material see Current Week: http://www.solar.isas.ac.jp/sxt_co/SXTweekly.html Index: http://www.solar.isas.ac.jp/sxt_co/index.html The science nugget (week 98_38) shows some images of a major over-the-limb event from Sep. 15; we didn't learn much from this event, but it must have been a nice one. CAMPAIGNS Karin Muglach (TRACE/La Palma) PERSONNEL Nariaki Nitta returned to Palo Alto. SEMINARS 17-Sep-98 - none; 2/3 of the organizers were away from ISAS. TABLE PLAN, WEEK 39 (21-Sep-98 - 27-Sep-98) We look forward to synchronizing again with SOHO. There seem to be no interesting coordinated observations planned for this week. ________________________________#_______________________________ JST Day UT Start Time Pass Table ID Monday 21-Sep-98 02:59 3 980920 P3 ARS1 DARKCAL Tuesday 21-Sep-98 23:51 2 980921 P2 ARS1 SPECIAL Tuesday 22-Sep-98 01:34 4 980922 P4 ARS1 DIF Wednesday 23-Sep-98 00:09 2 980922 P2 ARS1 STD Thursday 23-Sep-98 22:43 2 980923 P2 ARS1 STD Friday 24-Sep-98 23:00 2 980924 P2 ARS1 STD Saturday 25-Sep-98 23:18 2 980925 P2 ARS1 STD Note that the naming convention uses the UT day number of the first pass of the day. This plan may change during the week. This plan differs from the one sent around last week in that we've added a second table on Tuesday. 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.