CHIEF OBSERVER'S REPORT for Week 50 10-Dec-01 through 16-Dec-01 J. Sato, D. McKenzie and A. Takeda GENERAL Solar activity was high in this week. Two X class flares occurred, with GOES classes X2.8 and X6.2. From 12-dec to 14-dec, we also observed 6 M class flares. SXT TECHNICAL A Yohkoh spacecraft problem has occurred. See below for some details. SXT SCIENTIFIC For Web material see the science nuggets: Current Week: http://isass1.solar.isas.ac.jp/sxt_co/011214.html Index: http://isass1.solar.isas.ac.jp/sxt_co/index.html This week's nugget describes obervations of the solar eclipse of Dec. 14, 2001. CAMPAIGNS No coordinated observationsl campaigns were supported this week. For SXT plans, see: http://isass1.solar.isas.ac.jp/sxt_co/sxt_future.html For SXT completed campaigns, see: http://isass1.solar.isas.ac.jp/sxt_co/sxt_catalog.html PERSONNEL A. Takeda and J. Sato in residence. D. Mckenzie left on Saturday. SEMINARS There was no seminar this week. Special Remarks Yohkoh has stopped sending scientific data since last weekend. The spacecraft is alive, but in an undesirable attitude. Associated with this is a battery-charging problem, and at present it is not clear when normal observations can resume. Recovery certainly will not happen before the New Year's holiday. Accordingly this will be the last SXT table plan and weekly report of this year. When Yohkoh operations recover, we will resume weekly reports with great pleasure. In the meanwhile we will thank all of the readers of these reports. The flow of science nuggets will continue and we may convert these reports into weekly e-mail notifications of new science nuggets in the interim period. Certainly many people continue to obtain new and interesting scientific results from the Yohkoh data. Jun Sato and Takeda Aki (SXT COs)