15 May 1999 David McKenzie CHIEF OBSERVER'S REPORT for Week 20 10-May-99 to 15-May-99 GENERAL Solar activity dropped during the week; the GOES background was at about B5 by the end of the week. SXT supported JOPs 104 and 100. SXT TECHNICAL During the first part of week 20 the CCD developed an artifact at the northwest limb, due to overexposure. That artifact disappeared after (a) AEC was re-enabled and (b) the bright solar active region which was responsible rotated behind the limb. Some computer problems affected us during the weekend; service personnel are expected to bring us back to full capability today (Monday). 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/990514.html Index: http://www.solar.isas.ac.jp/sxt_co/index.html This week we explore some interesting behavior of loops interconnecting the north and south hemispheres. CAMPAIGNS SXT took part in JOP 104 and JOP 100, making ARS2 pointing for both and capturing many images of active regions. 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 No personnel changes. SEMINARS There was no seminar this week. SXT TABLE PLAN, WEEK 21 (17-May-99 to 22-May-99) SOHO JOP 017 (arch filament systems), JOP 103 (TRACE moss): both require ARS2 pointing, but allow AEC-enabled exposures. If the chosen targets are sufficiently bright and solar activity permits, we will try to support. ________________________________#_______________________________ JST Day UT Start Time Pass Table ID Monday 17-May-99 06:57 2 990517 P2 ARS2 ST+J017 Tuesday 18-May-99 08:55 3 990518 P3 ARS2 DK+J017 Wednesday 19-May-99 09:10 4 990519 P4 ARS2 ST+J017 Thursday 20-May-99 09:25 4 990520 P4 ARS2 DF+J103 Friday 21-May-99 04:31 2 990521 P2 ARS2 ST+J103 Saturday 22-May-99 08:12 4 990522 P4 ARS1 STD The "J017" in the name refers to JOP 017 (or JOP 103, respectively). This plan is subject to change. 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.