SXT Status Report 4 Nov. 1997 - 17 Nov. 1997 (Weeks 45-46) D. McKenzie, N. Nitta, H. Hudson, S. Savy SUMMARY Solar activity remained at a high level during this period, with six M flares and two X flares. SXT has operated well with no special problems related to the high activity. There were no formal campaigns. SOLAR ACTIVITY The higher activity has continued for long enough now, almost four months having passed since the GOES low channel was below the A level (ie, near detector background) so that even a skeptic would have to admit that the Sun has changed. The X9 flare of 6 November provides us with a chance to review our readiness for future big flares; there are some changes in our routine flare observing sequences to emphasize the good measurement of flare ejecta. The Nov. 6 event did show ejections in about the vertical direction. Image saturation in the patrol image (used to define the high-resolution field of view) "pulled" the PFIs off image center, but not outside the field of view. This would be a concern with a still bigger flare. We have also looked to see if there was any perceptible blemish left on the CCD from the violent overexposure in some images, but apparently not. SXT has passed its first test of the new cycle with flying colors! SXT INSTRUMENT STATUS AND CALIBRATION ACTIVITIES SXT continues to operate well. Some problems with SXT operations software started on Nov. 15, resulting in confusion about the status of the observing tables. This problem was identified and corrected on the 18th. A one-day CCD bakeout took place on Nov. 12 with no problems. Our regular schedule now is to do a one-day bakeout once per quarter, so the next would be due approximately in March 1998. Data archiving is complete through Week 44, 1997. The next week (45) will contain the recent X flares and related activity. The Web reporting has continued, with weekly pages giving the SXT operations reports and a "science bullet". There are now four of these bullets on line: ftp://isass0.solar.isas.ac.jp/pub/sxt_co/report_971024.html dimming ftp://isass0.solar.isas.ac.jp/pub/sxt_co/report_971031.html EIT Calroc ftp://isass0.solar.isas.ac.jp/pub/sxt_co/report_971107.html Nov 6 flare ftp://isass0.solar.isas.ac.jp/pub/sxt_co/report_971114.html Nov 14 LDE Do our readers like these? They are pretty easy to do, and there is always something worth noting in these beautiful data. PASS CONFLICTS AT KSC Week 45, six total passes lost at KSC to other programs. Week 46, eight total passes lost at KSC to other programs. CAMPAIGNS There were no formal campaigns during these two weeks. For Yohkoh target planning, the SXT weekly observing plan is available on the Web at http://www.space.lockheed.com/SXT/html2/First_Light.html or with "finger campaign@isass0.solar.isas.ac.jp | more". See http://sohowww.nascom.nasa.gov/operations/targets/today for SoHO target planning. VISITORS AND PERSONNEL Canfield departed after a swirl of activity in Japan; Hudson traveled to California and Washington. SEMINARS There were no seminars during these two weeks because of unavailability of the organizers. OTHER SCIENCE TOPICS The occurrence of an X9 flare has caused a fair amount of excitement. In this case rumors have it that the HXS sensor (of WBS) saturated, and that HXT could see "superhot" emission at 70 MK out to the 33 keV channel. The SXT data showed complex flare structure but the bulk of the emission came from an extremely compact, hot source. The flare drove the thin filters into "filter alternation" as the last line of defense to protect the CCD from severe overexposure. As mentioned above, there were also ejecta. The area at half maximum intensity of the X-ray emission was only about 3.5 10^18 cm^2 at GOES maximum. TOHBANS Tohbans for Week 45: SSOC : Kumagai & Watanabe KSC : Kubo & Kasahara SXT_CO: D. McKenzie, N. Nitta SXT_SW: G. Slater Tohbans for Week 46: SSOC : Sterling & Bargatze KSC : Kubo & Sasaki SXT_CO: N. Nitta SXT_SW: G. Slater