16 December 1996 M Weber SXT CHIEF OBSERVER'S REPORT AND TABLE PLAN CHIEF OBSERVER'S REPORT for Week 50 09-Dec-96 to 15-Dec-96 SOLAR ACTIVITY This week the Sun began once more to turn its more active side to face us. Background X-ray flux, as measured by GOES, climbed from its sub- A level basement to about B1 magnitude. One active region crossed the disk, another new-cycle region formed at a high northerly latitude just before crossing the west limb, and two more entered from the eastern limb. All of these regions showed relatively large variations in activity, but the absolute magnitude of events only crossed the C-level threshold a handful of times. SXT INSTRUMENT STATUS The SXT continues to function well. CAMPAIGNS SoHO JOP 057 (Polar Jets and "Jetlets"). We had several successful days of joining this campaign to focus on the solar north pole to look for soft X-ray jet-features. From only the KSC data, Hara-san was able to find several such events, captured quite nicely with SXT PFIs. We look forward to future results from this work. On 12-Dec (UT), a temporary "saturation artifact" formed in the SXT CCD. We believe this was due to a combination of (1) the long exposures we use for JOP 057 observations, (2) the concurrent ARS0 mode, and (3) the occurrance of soft X-ray events on the limb. Initial analysis indicated that the half-life of the artifact was long enough to recommend a hiatus on SXT participation in JOP 057. We emphasize that SXT was, and is, able to continue with its normal operations. We intend to re-evaluate the situation on Monday to determine if SXT can re-join JOP 057 for the final day of the camapign. ADDENDUM: Analysis today indicates the artifact is decaying as expected, but the immanent arrival of another AR at the east limb has prompted us to be cautious. SXT operations with JOP 057 have been cancelled for 16-Dec. (MW) Coordinated observations with SoHO/CDS. Through regular email contact with Dr Peter Young, we attempted to coordinate mutually supportive observations between the SXT and CDS instruments this week. There were three or four interesting regions in view at each time, so target selection was challenging. SEMINARS Unfortunately for us, there were no Yohkoh seminars in Week 50. SXT TABLE PLAN FOR WEEK 51 (15-Dec-96 to 22-Dec-96) In Week 51, SXT will be participating in JOP057 to observe jets and "jetlets" in the polar region. This requires a special SXT Table which is run during a period of two or three KSC Contact Passes in a day. The campaign is scheduled to end on 17-Dec. The dark-calibration table will be loaded on Tuesday, and diffuser frames will be inserted into the FFI Qt/H table on Thursday. All terminator opportunities are expected to be used. KSC Time (start) in JST Pass Table ID _____________(= UT + 9 hrs)______#_______________________________ Sunday 15-DEC-96 ----- No SXT Table load ----- Monday 16-DEC-96 ----- OPERATIONS HOLIDAY ---- Tuesday 17-DEC-96 05:56 3 961216 P3 ARS1 DARKCAL Wednesday 18-DEC-96 02:49 2 961217 P2 ARS1 STANDARD Thursday 19-DEC-96 03:08 2 961218 P2 ARS1 STD+DIFF Friday 20-DEC-96 01:44 2 961219 P2 ARS1 STANDARD Saturday 21-DEC-96 ----- No SXT Table load ----- Sunday 22-DEC-96 ----- No SXT Table load ----- *** Please note that this table plan may change during the week. *** Continuing requests: We request that KSC tohbans continue to dump a patrol image each time an SXT table is loaded to facilitate the study of optimizing ARS parameters during quiet times. SSOC TOHBAN, please e-mail any terminator schedule to the chief observer (sxt_co@isass0) so that he can decide about filters and offpoints.