SXT Status Report July 10- July 24, 2000 (Weeks 29-30) B. Handy, H. Hudson SUMMARY At last, some quite high activity, including X-class flares; SXT and Yohkoh performed well. SOLAR ACTIVITY The new activity recognized early via a MacIntosh warning of a developing "super region", NOAA 9077, which attained a sunspot area exceeding 1000 millionths on July 11, with a delta configuration, and duly produced X-class flares on July 11, 12, and 14. The event on the 14th (Bastille Day again) was exceptionally well-observed both by Yohkoh and by TRACE and was the largest yet of this cycle. We have now had 11 X-class flares this year. Also of course an appropriate number of M-class flares, more than thirty during these two weeks. On July 21, just for illustration, NOAA listed 17 active regions, all of them with delta spot configurations (that's a bit odd), and a total of 231 individual spots. The flare trigger level remained at at 2x normal during this interval, in order not to have continuous triggering. OBSERVING CAMPAIGNS There were no organized campaigns, but we were pleased enormously to see the X-class flare of July 14 to have been well-observed both by Yohkoh and by TRACE. We are now planning support for SERTS observations of DEM, in conjunction also with the VLA, in week 31. Please see our webpages for more details about campaigns past and future: http://isass1.solar.isas.ac.jp/sxt_co/sxt_catalog.html http://isass1.solar.isas.ac.jp/sxt_co/sxt_future.html SXT INSTRUMENT STATUS AND CALIBRATION ACTIVITIES No unusual acivities took place during the reporting interval. We ought to have done a CCD bakeout but activity was too high to risk taking a day off. TELEMETRY DOWNLINKS Week Wallops Goldstone Canberra Madrid NASA ISAS 29 33 0 0 3 36 31 30 32 1 1 4 38 34 SXT OBSERVING SEQUENCE TABLES ------------------------------------------------- JST Day UT Date & Time Pass Table ID ================================================= Monday AM 10-JUL-00 01:56 3 000709 P4 ARS1 DARK* Tuesday AM 10-JUL-00 19:16 1 000710 P1 ARS1 DIFF* Tuesday AM 11-JUL-00 00:22 4 000710 P4 ARS1 STD* Wednesday AM 11-JUL-00 00:30 4 000711 P3 ARS1 STD* Thursday AM 12-JUL-00 19:31 3 000712 P3 ARS1 STD* Friday AM 13-JUL-00 21:21 3 000713 P4 ARS1 STD* Monday AM 16-JUL-00 20:02 3 000716 P3 ARS1 DARK* Tuesday AM 17-JUL-00 18:28 2 000717 P2 ARS1 DIFF* Tuesday AM 17-JUL-00 21:52 4 000717 P4 ARS1 STD* Wednesday AM 18-JUL-00 20:18 3 000718 P3 ARS1 STD* Thursday AM 19-JUL-00 18:44 3 000719 P3 ARS1 STD* Friday AM 20-JUL-00 17:09 2 000720 P2 ARS1 STD* Saturday AM 21-JUL-00 18:59 3 000721 P3 ARS1 STD* Sunday AM 22-JUL-00 15:43 2 000722 P2 ARS1 STD* ================================================= Data reformatting is complete through 1-Jul-00 (week 00_27). SCIENCE Science Nuggets 7-Jul-00: "Spiny arcades" Ruminations about spiny arcades, which Yohkoh discovered and which led to the first observations of one form of coronal dimming, and of supra-arcade downflows. Another nice one happened on June 2, 2000 prior to the three X-class flares in June, and from the same region. 14-Jul-00: "Building up to a feverish pitch" Noting the growth of the "super-region", and then paying homage to the X5.7 flare of July 14. Probably a second nugget will have to be written on this beautiful phenomenon. 21-Jul-00: "Cusps upon cusps" Successive major flares in the same active region left different cusp structures - in other words, the second event apparently restructured the field from the configuration just established the day before. The opposite kind of behavior had been reported in a science nugget a couple of months ago, so we continue to be surprised. The full list of nuggets is kept on http://isass1.solar.isas.ac.jp/sxt_co/index.html and the current week's nugget also normally resides on http://isass1.solar.isas.ac.jp/sxt_co/SXTweekly.html PERSONNEL Hudson was absent from ISAS for four days; Handy returned to the U.S. on July 21. TOHBANS (spacecraft operators) Tohbans for week 29 SSOC: Y. Suematsu, H. Isobe KSC: S. Masuda, T. Sekii SXT_CO: B. Handy SXT_SW: - Tohbans for week 30 SSOC: M. Hagino, T. Watanabe KSC: T. Miyawaki, T. Sekii SXT_CO: B. Handy, H. Hudson SXT_SW: -