SXT Status Report January 29, through February 18, 2001 (Weeks 5-7) A. Takeda, H. Hudson SOLAR ACTIVITY Activity has been amazingly low considering the phase of the solar cycle. Only one M-class flare (almost exactly zero UT February 3) has occurred. As usual in cases like this, we hope that the Sun is saving its fireworks for the HESSI launch. Also we note that the doldrums extend globally (ie, last longer than 1/2 rotation) even though there have been one or two LASCO reports of "backsided" halo CMEs. OBSERVING CAMPAIGNS We carried out no cooperative observing programs during this interval, but have a target-of-opportunity (TOO) search for sigmoid structures under way since Dec. 9. 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 Instrument status is good, with no new problems to report. No updates of the normal pointing were needed and there is no obvious sign of pointing anomalies; during Week 7 Yohkoh underwent a normal extended Canopus eclipse period, during which roll errors can accumulate. TELEMETRY DOWNLINKS Week Wallops Santiago Goldstone Canberra Madrid NASA Japan 05 25 7 7 0 12 51 27 06 27 11 12 0 8 58 29 07 33 13 8 1 6 61 30 Kagoshima should average 6*5+2 = 32 and the NASA target is 7*6 = 42. We have started again to get Santiago passes, which restores some of the flexibility in telemetry scheduling. SXT OBSERVING SEQUENCE TABLES ============================================================== JST Day UT Date & Time Pass Table ID -------------------------------------------------------------- Tuesday AM 29-JAN-01 17:29 1 010129 P1 ARS1 DIFF+XBP* Tuesday AM 29-JAN-01 22:33 4 010129 P4 ARS1 STD* Wednesday AM 30-JAN-01 17:31 1 010130 P1 ARS1 STD+XBP* Wednesday AM 30-JAN-01 20:54 3 010130 P3 ARS1 STD* Thursday AM 31-JAN-01 19:16 2 010131 P2 ARS1 DARK* Thursday AM 31-JAN-01 22:40 4 010131 P4 ARS1 STD* Friday AM 1-FEB-01 15:57 1 010201 P1 ARS1 STD+XBP* Friday AM 1-FEB-01 21:01 4 010201 P4 ARS1 STD* Saturday AM 2-FEB-01 15:59 1 010202 P1 ARS1 STD+XBP* Saturday AM 2-FEB-01 21:40 4 010202 P1 ARS1 STD* Monday AM 4-FEB-01 17:46 2 010204 P2 ARS1 STD* Monday PM 5-FEB-01 14:26 1 010205 P1 ARS1 STD+XBP Tuesday AM 5-FEB-01 19:32 4 010205 P4 ARS1 STD* Tuesday PM 6-FEB-01 14:29 1 010206 P1 ARS1 DIFF+XBP Wednesday AM 6-FEB-01 19:35 4 010206 P4 ARS1 STD* Wednesday PM 7-FEB-01 14:32 2 010207 P2 ARS1 DARK Thursday AM 7-FEB-01 17:56 4 010207 P4 ARS1 STD* Thursday PM 8-FEB-01 12:54 1 010208 P1 ARS1 STD+XBP Friday AM 8-FEB-01 16:17 3 010208 P3 ARS1 STD* Friday PM 9-FEB-01 12:56 1 010209 P1 ARS1 STD+XBP Saturday AM 9-FEB-01 16:20 3 010209 P3 ARS1 STD* Saturday PM 10-FEB-01 11:19 1 010210 P1 ARS1 STD+XBP Saturday PM 10-FEB-01 14:41 3 010210 P3 ARS1 STD Monday PM 12-FEB-01 14:47 3 010212 P3 ARS1 STD Tuesday PM 13-FEB-01 13:08 3 010213 P3 ARS1 DXBP Wednesday PM 14-FEB-01 09:48 1 010214 P1 DARKCAL Wednesday PM 14-FEB-01 14:53 4 010214 P4 STD Thursday PM 15-FEB-01 13:14 3 010215 P3 STD Friday PM 16-FEB-01 11:35 3 010216 P3 STD Saturday PM 17-FEB-01 11:37 3 010217 P3 STD -------------------------------------------------------------- Data reformatting is complete through 6-Jan-01 (week 01_01). OBSERVING SEQUENCES: The intense table-change activity noted above resulte from an effort to get daily DPE 30 exposures for the long-term bright-point campaign effort (Hara-Nakakubo). After e-mail discussion (Acton, Hara, Hudson, McKenzie, Nitta) the system has been changed. Now we're just doing these 30-sec exposures once per week, with the weekly diffuser calibration table. These exposures are only marginally better than the normal long exposures for XBP studies (deeper but more saturated). The judgement is that the XBP program can continue just fine without them, but that somebody may figure out a long-term application for which a once-a-week sampling might provide a good database. SEMINARS: Speaker: A. Stepanov Title: "Joule heating and electron acceleration in a single loop flare model" * Not about CSHKP, very refreshing! Speaker: V. Melnikov Title: "Temporal evolution of solar flare microwave and hard X-ray spectra: evidences for electron spectral dynamics" * Great timing with respect to the science nugget for Feb. 9 (http://isass1.solar.isas.ac.jp/sxt_co/010209.html). Speaker: D. P. Choudhary Title: "Flows in the Active Region" * Photospheric velocity fields derived from Stokes V and their systematic behavior during special magnetograph runs at Huntsville. SCIENCE NUGGETS: 2-Feb-01: "A dark 'S' erupted!" - Points out an excellent example of the sigmoid => eruption morphology, but this time without a coronal sigmoid. 9-Feb-01: "A most peculiar high-energy event" - A mm-wave extended burst identified with a faint arcade structure; no doubt a good example of differential particle trapping as discussed in the Melnikov seminar (see above). Thanks to Silja Pohjolainen. 16-Feb-01: "A million-kilometer jet" - Rather wonderful bipolar jet (is this terminology right? A "filament channel excitation"?) of great dimension and high velocity but no eruption. Thanks to Ilia Chertok. 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: H. Hudson returned Feb. 3 and departed 17.; G. Slater will depart Feb. 19. TOHBANS (spacecraft operators) Tohbans for week 5 SSOC: R.Kano, Adachi KSC: H.Itoh, T.Yokoyama SXT_CO: A. Takeda SXT_SW: J. Bartus, G. slater Tohbans for week 6 SSOC: T. Sekii, H. Hudson KSC: T.Yokoyama, T. Tamura SXT_CO: H. Hudson SXT_SW: J. Bartus, G. Slater Tohbans for week 7 SSOC: H. Ishizaki KSC: T. Tamura, Y. Hanaoka SXT_CO: H. Hudson, A. Takeda SXT_SW: J. Bartus, G. Slater