SXT Status Report 26 March - 9 April, 2001 (Weeks 13-14) A. Takeda, H. Hudson SOLAR ACTIVITY Tremendous activity appeared during these two weeks (in like a lion out like a lamb), including an X20 GOES event among five X-class flares from two different active regions. Of these AR 9393 achieved a total spot area of 2440 millionths on March 30. We quote from the status report of two weeks ago: "The region AR 9393 contains a naked-eye spot (approaching 1000 millionth) and it is predicted to produce major events." In fact, Pat McIntosh basically got this one right, predicting a flare at the X10 level within 24-48 hours (it happened slightly outside this window). OBSERVING CAMPAIGNS We continued to be on the alert for sigmoids as Target Of Oportunity. 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 SXT continued to work well. No new problem has been reported. TELEMETRY DOWNLINKS Week Wallops Santiago Goldstone Canberra Madrid NASA Japan 13 32 1 7 0 12 52 35 14 30 3 8 0 8 49 25 Kagoshima should average 6*5+2 = 32 and the NASA target is 7*6 = 42. SXT OBSERVING SEQUENCE TABLES ============================================================== JST Day UT Date & Time Pass Table ID -------------------------------------------------------------- Monday 25-MAR-01 16:51 2 010325 P2 ARS1 DARK* Monday 25-MAR-01 21:57 5 010325 P4 ARS1 STD* Tuesday 26-MAR-01 18:36 4 010326 P4 ARS1 DIFF* Wednesday 27-MAR-01 16:56 3 010327 P3 ARS1 STD* Thursday 28-MAR-01 18:40 4 010328 P4 ARS1 STD* Friday 29-MAR-01 15:18 2 010329 P2 ARS0 STD* Saturday 30-MAR-01 15:20 2 010330 P2 ARS1 STD* Sunday 31-MAR-01 15:22 3 010331 P3 ARS1 STD* Tuesday 2-APR-01 15:25 3 010402 P3 ARS1 STD* Wednesday 3-APR-01 15:27 4 010403 P4 ARS1 STD* Wednesday 4-APR-01 12:04 2 010404 P2 ARS1 DARK Thursday 4-APR-01 15:27 4 010404 P4 ARS1 DIFF* Thursday 5-APR-01 10:25 1 010405 P1 ARS1 STD Friday 6-APR-01 12:08 3 010406 P3 ARS1 STD Saturday 7-APR-01 12:10 3 010407 P3 ARS1 STD Data reformatting is complete through March 24, 2001. OBSERVING SEQUENCES: During this interval we worked with standard stables, continuing the regular use of the 4x long exposures for the movie images. An analysis of the results of this suggests that it is working at about 10% duty cycle, ie every tenth EIT wave should be observable by SXT in its standard movie images, but with two-minute cadence. As yet no full scientific analysis has been carried out. SCIENCE NUGGETS: 30-Mar-01: "Aurora seen in Palo Alto!" stimulated by the first of the X-class flares from AR 9393. Yohkoh got no data on this one, so we focused on the aurora borealis - seen as far south as Big Bear Solar Observatory and certainly in Palo Alto. 6-Apr-01: "Most powerful flare in decades" stimulated by the mammoth (but it was only 1B in H-alpha) flare of April 2. Again Yohkoh did not get such good coverage, but as an interesting aside this flare was followed half a day later by an X-class flare in a different active region, thus refuting the idea that two X-active regions cannot exist on the Sun simultaneously. The full list of recent 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 For the complete nugget archive, see one of the following sites. http://isass1.solar.isas.ac.jp/sxt_co/index.html SEMINARS: T. Sakurai (NAO): "Interpolation of Images with Photon Number Conservation" This talk presented an analysis of a mathematical technique for a better method of pixel interpolation. There was some debate about the meaning of "better" and of "interpolation", but little attention was paid to the suggestion that "pixel" should be debated too. But, come to think of it, "number" also caused some controversy. All in all clearly interesting, especially following the CDAW of January. PERSONNEL: No changes. VISITOR: S. Kahler continues his intensive study on coronal hole boundaries. He has now drawn a cartoon. S. Pohjolainen arrived. TOHBANS (spacecraft operators) Tohbans for week 13 SSOC Tohbans: A.Asai, H.Isobe, T.Watanabe KSC Tohbans: Y.Katsukawa, Y.Matsumoto SXT_CO: A. Takeda, H. Hudson SXT_SW: J. Bartus Tohbans for week 14 SSOC Tohbans: T.Sakurai, S.Morita KSC Tohbans: Y.Matsumoto, H.Takahashi SXT_CO: H. Hudson SXT_SW: J. Bartus