SXT Status Report August 7 - August 21, 2000 (Weeks 33-34) L. Fletcher, H. Hudson SUMMARY Activity remained low, only two M-class flares. SXT continued to function well, and we supported Max Millennium campaign #10 (flares, unfortunately). SOLAR ACTIVITY The solar activity was astonishingly low, although we have had 11 X-class flares thus far this year. The July 14 event, the biggest of this cycle, has attracted a lot of attention and will be the subject of a special session at the AGU meeting in December. Of the two M-class flares during these two weeks, one chose to occur during one of our infrequent bakeouts, and we did not obtain any observations of it. OBSERVING CAMPAIGNS Yohkoh and SXT supported Max Millennium Campaign #10 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 A routine CCD bakeout occurred on August 8 (one day). As mentioned, the M-class flare that occurred on that day was not correctly observed, owing probably to improper setting for the on-board ARS (flare-finding) function. We are studying this and will develop a better plan - even with the CCD warm we should be able to get good flare observations. For bakeout details, see http://isass1.solar.isas.ac.jp/sxt_co/bake_000808.html - there were some interesting aspects to this one. TELEMETRY DOWNLINKS Week Wallops Goldstone Canberra Madrid NASA ISAS 33 30 5 1 0 36 25 34 34 3 1 1 39 29 35 32 3 5 3 43 26 Yohkoh has stopped losing KSC contact passes to ASCA - a sad feeling. We are now getting two 34-m passes per Sunday. SXT OBSERVING SEQUENCE TABLES ------------------------------------------------- JST Day UT Date & Time Pass Table ID ================================================= Monday PM 07-AUG-00 10:54 4 000807 P4 ARS1 DARK Tuesday PM 08-AUG-00 05:55 1 000808 P1 ARS0 BAKE Wednesday PM 09-AUG-00 09:26 3 000809 P3 ARS1 RAPID Thursday PM 10-AUG-00 04:28 1 000810 P1 ARS1 DIFF Thursday PM 10-AUG-00 07:51 3 000810 P3 ARS2 RAPID Thursday PM 10-AUG-00 09:34 4 000810 P4 ARS2 RAP-F Saturday PM 12-AUG-00 08:05 3 000812 P3 ARS1 STD Monday PM 14-AUG-00 06:38 3 000814 P3 ARS1 RAPID Tuesday PM 15-AUG-00 01:42 1 000815 P1 ARS2 DARKFL Tuesday PM 15-AUG-00 06:46 4 000815 P3 ARS2 DIFFL Wednesday PM 16-AUG-00 06:53 4 000816 P3 ARS2 RAPFL Thursday PM 17-AUG-00 03:35 2 000817 P2 ARS2 RAPFL Friday PM 18-AUG-00 03:43 2 000818 P2 ARS2 RAPFL Saturday PM 19-AUG-00 03:50 2 000819 P2 ARS1 STD ================================================= Data reformatting is complete through 23-Jul-00 (week 00_30). SCIENCE Observing sequences: We have been experimenting both with the FFIs and the PFI flare-mode observing sequences. During these two weeks we obtained seven days of "RAPID" FFIs, which means sets of long-exposure Q-resolution images yielding a 32-second sampling interval. Our hope with this is to catch global waves related to EIT waves, Type II exciters, or Moreton waves. To do this the flare threshold has remained at its higher level, about C6. Thus far this mode has been disappointing, partly no doubt because of the low activity, and we plan to return to the normal FFI mode. For flare mode, we have for the first time begun to obtain 2x2 flare-mode images. At present the flare table has two entries, one normal AEC exposure and one overexposed AEC exposure (the McKenzie design). This results in a 16-sec sample interval and a 5 arc min field of view. The M-class flare of August 12 was observed in this mode and looked very good - nice wispy ejecta well-observed far from the flare core. No wave! We plan to continue this until a few more flares have been observed. The "velocity filter" for global wave detection with this mode would be about v < 1500 km/s for about four glimpses of a wave originating at the flare core. Seminars: none Nuggets: 4-Aug-00: "Remarkable particle track" What must be a rare occurrence in a PFI: a long (1.4 mm) curved particle track. This nugget discusses the ins and outs of particle tracks in CCDs, then winds up with the Bastille Day fireworks of the "snowstorm" observed by EIT (thanks to Sam Freeland). 11-Aug-00: "Catching a jet" The nugget this week describes the catching of an X-ray jet. The study of these animals will doubtless be furthered by this fortunate, and rare, jet occurrence inside the PFI (so, high resolution, highish cadence). The nugget remarks that the jet is associated with a microflare loop, but that it appears to originate in fact in a fainter loop to the north, which may not be in agreement with the `standard theory' of jet formation. 18-Aug-00: "Extreme southerly latitude" The nugget this week describes a very southerly active region, asking just how unusual such a thing is. At the last gasp this region, at S36, grew rapidly and produced a nice C-class flare, of course during Yohkoh orbit night. Read the nugget, follow its links, and learn what Spoerer's Law is. 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 No changes. TOHBANS (spacecraft operators) Tohbans for week 33 SSOC: T. Miyagoshi, K. Nakakubo KSC: T. Koyama, M. Hata SXT_CO: L. Fletcher, H. Hudson SXT_SW: - Tohbans for week 34 SSOC: H. Tonooka KSC: M. Hata, R. Haga SXT_CO: L. Fletcher SXT_SW: -