February 21, 1999 Hugh Hudson SXT CHIEF OBSERVER'S REPORT AND TABLE PLAN CHIEF OBSERVER'S REPORT for Week 8 16-Feb-99 to 22-Feb-99 GENERAL SXT continues to perform properly, and there is nothing special to report. Solar activity continued at a moderate level. resumed after the quiet interval. SXT TECHNICAL Yohkoh executed a "normal pointing update" on Feb. 20, the first since December. Nariaki Nitta found an SXT image with an undocumented exposure time, but we have seen no other examples of this and there were possible explanations in the database software; no conclusions yet. A series of e-mail exchanges among ISAS, JPL, and Wallops revealed that the Santiago station is still available to us. This will, we hope, help to eliminate the 12-hour data gaps we have been having since last fall, on Yohkoh telemetry holidays at KSC. 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/990219html Index: http://www.solar.isas.ac.jp/sxt_co/index.html The current Nugget continues discussion of the trans-equatorial interconnecting loops, which continue to thrill and amaze. Since this is the fifth science nugget already on this topic, we will probably do something else next week! CAMPAIGNS SXT is attempting to coordinate with VLA observations of a weak active region. In addition, on Feb. 24 there will be an ARS2 activity scheduled tentatively for 11-17 UT, in which we will try to catch clean loops in TRACE, SOHO, and Yohkoh observations for analysis of loop geometry. Please see the general coordination page at: http://sec.noaa.gov/solcoord/solcoord.html For SXT plans, finger campaign@isass0.solar.isas.ac.jp. PERSONNEL L. Acton returned from the Far North with glowing reports. SEMINARS M. Shimojo (GUAS/NAO) "Studies of Solar Coronal X-ray Jets" This was a report on his successful thesis. There was much discussion! ^L SXT TABLE PLAN, WEEK 9 (22-Feb-99 to 27-Feb-99) The VLA will continue its active-region observations, and we plan to continue with support as possible. In addition TRACE and SOHO will be making a study of isolated loops, and we've been asked to help with that (Harry Warren, Jim Klimchuk). The VLA dates are Feb. 27 and 28, time range 18:00-23:00 UT approximately. ________________________________#_______________________________ JST Day UT Start Time Pass Table ID Monday 22-FEB-99 03:34 4 990221 P4 ARS2 LOO (*) Tuesday 22-FEB-99 22:42 2 990222 P2 ARS2 DARKCAL Wednesday 24-FEB-99 02:23 4 990223 P4 ARS2 LOO (*) Thursday 24-FEB-99 23:13 3 990224 P3 ARS2 DIF Friday 26-FEB-99 01:12 4 990125 P4 ARS2 LOO (*) Saturday 26-FEB-99 20:20 2 990126 P2 ARS1 STD (*) => table name adopts the convention of UT date of first pass isass0.solar.isas.ac.jp> cat table_plan.99_08 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.