Page 1 PROGRESS REPORT THE SOLAR-A SOFT X-RAY TELESCOPE (SXT) PROGRAM (CONTRACT NAS8-40801) (for February 2000) OVERVIEW The YOHKOH Mission is a program of the Japanese Institute of Space and Astronautical Science (ISAS) with collaboration by the U. S. National Aeronautics and Space Administration and the U. K. Science and Engineering Research Council. The YOHKOH satellite was launched on 30 August 1991 from Kagoshima Space Center (KSC) in Japan. The purpose of this mission is to study high energy phenomena in solar flares and the Sun's corona. Under an international cooperative agreement, Lockheed Martin, under NASA contract, is providing a scientific investigation using the Soft X-ray Telescope (SXT), one of the primary experiments of the mission. The SXT was developed at the Lockheed Martin Solar and Astrophysics Laboratory in cooperation with the National Astronomical Observatory of Japan, and the Institute for Astronomy of the University of Tokyo. MAJOR PROGRAMMATIC ACTIVITIES IN THE MONTH Effort is continuing on the preparation of the proposal for continuation of the SXT operational and data analysis activities. All other activities are continuing with many publications forthcoming. SOLAR ACTIVITY In early February, activity soared, yielding an actual X-class flare (X1.2) at 5-feb 19:28. That brings this year's count to 12 M, 1 X for those interested in statistics. The GOES soft X-ray background was at mid-B level. An M3.0 flare occurred at 4-feb 09:20 and there were also several C-class flares. We are eager to see, of course, if the X-class shortfall of last year (possibly related to the "Gnevyshev Gap"?) continues. In mid-February, solar activity decreased, despite many active regions on the solar surface, with one M (M1.3, Feb 8) and seven C class flares. At one point (12 Feb) there were 13 numbered NOAA active regions, and the GOES background level hovered around C1. Two M-class flares commenced on Feb. 17, the first one in NOAA AR 8869 and the second in AR 8872. For both of the two flares, the impulsive phase took place during SAA passage followed by S/C night. In the later part of February, solar activity was moderately high, with M flares but no X flares. M-class flares occurred on Feb. 19 and on Feb. 20. The latter commenced during the S/C daytime, out of SAA, so it may have been well observed with Yohkoh. Two M-class flares on February 22 were observed in the main phases. Page 2 CAMPAIGNS There were no coordinated campaigns. We did, however, respond to requests for input on the appearance of large-scale interconnecting loops (Farnik) and well-observed streamer bases (Foley). We resumed "rapid run" long FFI exposures, obtaining two days of Q-resolution SFD-type images at 32-sec cadence. The idea here is to look for more wave events, especially for flares below the trigger threshold level (about C6 at present). SCIENCE Alexander worked on sunspot modeling with Neal Hurlburt, simulating time-dependent TRACE and SXT emission resulting from the dissipation of energy generated from sunspot magnetoconvection and transported to the corona as a Poynting flux. Canfield worked with various students on the analysis of SXT and MCCD data. Trish Van Lew studied SXT jet / MCCD surge events using the Blehm/Pevtsov list of jets and surges inferred from SXT sfd files throughout the mission to date. Angela Colman studied tether-cutting events similar to those observed by Canfield et al before the Nov 15 1991 event. Yuriko Yamazaki (ACE Language Institute) and Eric Erickson, and Tyler Bangs (Headwaters Academy) studied the relationship between sigmoids and signatures of eruptions in the SXT sfd movies on video disk. Fletcher worked on numerical simulations with Aschwanden; trying to understand both analytically and from simulations exactly how particles accelerated into a magnetic bottle drift in and out of the loss-cone, under the influence of scattering and field convergence. `Weak' and `strong' limits which people tend to use, because they're conceptually easy, don't do a very good job when compared with simulations. This could impact interpretations of HXR signatures. PUBLICATIONS Submitted: "Solar Activity", Alexander and Acton, one of the solar chapters to appear in "The Century of Space Science" "Evidence for the Flare Trigger Site and 3-D Reconnection in Multi-Wavelength Observations of a Solar Flare"; L. Fletcher, T. R. Metcalf, D. Alexander, L. A. Ryder and D. S. Brown, submitted to ApJ. "Looptop Hard X-ray Sources", L. Fletcher, in Proceedings of the 9th European Meeting on Solar Physics (ESA-SP 448), P.693. Accepted: "A Method to Determine the Heating Mechanisms of the Solar Corona", Page 3 E. R. Priest, C. R. Foley, J. Heyvaerts, T. D. Arber, D. Mackay, J. L. Culhane and L.W. Acton "Supra-arcade Downflows in Long-Duration Solar Flare Events", by D. E. McKenzie, Solar Physics. PUBLIC USE OF SXT IMAGES We are continuing to make Yohkoh/SXT images available for a variety of uses. Efforts continue to make selected images available on the LMSAL SXT WWW homepage (http://www.lmsal.com/SXT/). We receive requests for the Yohkoh posters (#2 and #3) by way of the form on the SXT homepage. Currently we receive requests via our homepage at the rate of 2 or 3 per day. The WEB access statistics in February were 200500 accesses and 9235 Mbytes transferred. YOHKOH OPERATIONS AND HEALTH Yohkoh and the SXT continue to function very well. A Y2K/Leap year problem cropped up in dsnfil program that generates the ephemeral data for the fem files and op_first_guess. dsnfil is a Fortran program that is based on the AOSLOS program that runs on the Facom mainframe. Masuda san kindly provided the fix for one of the subroutines. He commented that this "change is not complete. The next problem will occur in 2100 because there will be not Feb 29 in that year. I don't think Yohkoh continue to work in that year." The fix has been implemented and appears to be working well. HXA was off for two days owing to a mis-command at KSC. Accordingly, there will be no SXT pointing information for (approximately) 17-Feb 18:00 to 19-Feb 19:00. SXT experienced a normal level of Single Event Upset (SEU) events during the month: SXT Shutter Error 11-Feb-00 Pass 1: 000210-1443 Recovered in pass 4 SXT Bit Map Error 25-Feb-00 Pass 1: 000225-0929 Recovered in the same pass SXT Bit Map Error 29-Feb-00 Pass 1: 000229-0723 Recovered in the same pass Page 4 DATA FLOW Month Full Frame Images Observing Region Images Received Lost Received Lost Loss % QT FL Tot Thru Dec-97 513375 197867 2080583 427400 2507983 944339 27.08 Jan-98 5715 1803 23479 3232 26711 9918 27.08 Feb-98 6606 1644 25257 3606 28863 8989 23.75 Mar-98 6043 2056 23029 10399 33428 10939 24.66 Apr-98 6537 1103 22656 8087 30743 6339 17.09 May-98 7569 1838 28292 19018 47310 9868 17.26 Jun-98 6463 1638 24990 5618 30608 9051 22.82 Jul-98 6810 1892 27046 7357 34403 9970 22.47 Aug-98 5823 1960 22978 14126 37104 11167 23.13 Sep-98 6776 1432 21814 11626 33440 7753 18.82 Oct-98 6573 1901 23520 5198 28718 9220 24.30 Nov-98 6442 1695 25124 26948 52072 9920 16.00 Dec-98 5962 2005 21490 15770 37260 10561 22.08 Jan-99 5494 1825 20087 17620 37707 9622 20.33 Feb-99 5729 1525 30802 9798 40600 10630 20.75 Mar-99 6807 1844 24721 12354 37075 10064 21.35 Apr-99 6715 1371 25113 4179 29292 7791 21.01 May-99 6459 1807 35467 12092 47559 13757 22.44 Jun-99 6217 1915 23542 13051 36593 10086 21.61 Jul-99 5591 1745 20409 25747 46156 9670 17.32 Aug-99 6827 2503 21725 23361 45086 11844 20.80 Sep-99 5768 2011 21890 3434 25324 10846 29.99 Oct-99 5768 2308 22994 10487 33481 11517 25.59 Nov-99 7552 3425 20754 18772 39526 11974 23.25 Dec-99 7488 2791 22047 5354 27401 10663 28.01 Jan-00 5426 1736 19802 4040 23842 8958 27.31 Feb-00 5966 1759 19740 6168 25908 7758 23.04 Total 678501 247399 2699351 724842 3424193 1203214 26.00 Number of Full Frame Images Received: 678501 Number of Observing Region Images Received: 3424193 Total: 4102694 Approximate Number of Shutter Moves/CCD Readouts: 7010391 NOTES: * The loss of images is mainly due to BDR overwrites, but there are also occasional DSN dumps which are lost. * It is common to have observing regions which contain more than 64 lines, which requires multiple exposures to make a single observing region image. This is why the number of shutter moves is larger than the number of images received plus those lost. Page 5 ENGINEERING SUMMARY TABLE Month Avg Dark Level # of Dark Spikes CCD Warmings Front Optical (DN) (e/sec) Over 48 Over 64 High / # Support Trans Temp /Days Temp (%) Jan-98 56.06 958.0 212189 22121 23.9 N/A Feb-98 55.94 953.7 209254 22122 23.8 / 2 22.6 N/A Mar-98 56.29 966.6 213519 23249 21.8 N/A Apr-98 56.44 972.1 214676 23890 20.8 N/A May-98 56.90 989.4 215651 26905 21.4 N/A Jun-98 57.11 997.5 216285 28223 20.1 N/A Jul-98 57.01 993.7 215499 27493 21.4 N/A Aug-98 57.36 1006.7 217355 29544 20.9 N/A Sep-98 57.43 1009.5 218520 29683 20.9 N/A Oct-98 57.59 1015.3 220504 30221 21.3 N/A Nov-98 58.17 1037.0 223755 34614 22.5 / 2 23.4 N/A Dec-98 57.86 1025.5 221918 32420 23.8 N/A Jan-99 58.74 1058.6 227503 38238 23.1 N/A Feb-99 58.44 1047.4 224002 36198 23.2 N/A Mar-99 59.26 1078.1 227900 43051 21.7 N/A Apr-99 58.82 1061.4 225973 38963 23.8 / 1 21.4 N/A May-99 58.68 1056.4 225385 37726 21.6 N/A Jun-99 59.40 1083.0 230091 42440 22.0 N/A Jul-99 59.78 1097.5 231236 46337 23.8 / 1 20.6 N/A Aug-99 59.39 1083.0 229319 43067 21.7 N/A Sep-99 60.04 1107.3 231585 49084 21.8 N/A Oct-99 59.66 1092.9 229735 45263 22.8 N/A Nov-99 59.90 1102.0 231288 47102 23.0 N/A Dec-99 60.55 1126.3 233523 53920 22.5 / 2 25.3 N/A Jan-00 60.27 1115.9 233820 50214 23.4 N/A Feb-00 60.92 1140.0 235077 56720 23.9 N/A NOTES: * The dark current calculations are using full half resolution 2.668 sec images not taken in during the SAA. The dark current rate assumes a "fat zero" of 30.5 DN and a gain of 100 e/DN. * The entrance filter failure of 13-Nov-92 eliminated the capability of taking optical images, so the optical transmission is not available after Nov-92. It also caused an increase in the dark current signal, however some of the increase shown here is an increase in the readout noise and is not a function of exposure duration. Page 6 PERSONNEL TRAVEL SXT Foreign Travel between 1-FEB-00 and 29-FEB-00 HUDSON 1-FEB-00 * 29-FEB-00 * 29 (total of 29 days) MCKENZIE 1-FEB-00 * 29-FEB-00 * 29 (total of 29 days) SHIRTS 21-FEB-00 29-FEB-00 * 9 (total of 9 days) ---------------------------------------------------------------- Grand Total of 67 days for 3 people NOTE: The "*" signifies travel that actually ends after 29-FEB-00 SXT Foreign Travel between 1-MAR-00 and 31-MAR-00 ACTON 26-MAR-00 31-MAR-00 * 6 (total of 6 days) FLETCHER 5-MAR-00 25-MAR-00 21 (total of 21 days) HUDSON 1-MAR-00 * 4-MAR-00 4 11-MAR-00 25-MAR-00 15 (total of 19 days) MCKENZIE 1-MAR-00 * 6-MAR-00 6 (total of 6 days) NITTA 12-MAR-00 31-MAR-00 * 20 (total of 20 days) SHIRTS 1-MAR-00 * 6-MAR-00 6 (total of 6 days) ---------------------------------------------------------------- Grand Total of 78 days for 6 people NOTE: The "*" signifies travel that actually ends after 31-MAR-00 Respectfully submitted, Thomas R. Metcalf Frank Friedlaender Page 7 ------------------------------------------------------------------------------- NASA REPORT DOCUMENTATION PAGE (IN LIEU OF NASA FORM 1626) --------------------|--------------------------|------------------------------- 1. REPORT NO. | 2. GOVERNMENT | 3. RECIPIENT'S DR-01 | ACCESSION NO. | CATALOG NO. --------------------|--------------------------|------------------------------- 4. TITLE AND SUBTITLE | 5. REPORT DATE Monthly progress report - for the month of | 10 March 2000 February 2000 |------------------------------- | 6. PERFORMING ORG | CODE: O/L9-41 -----------------------------------------------|------------------------------- 7. AUTHOR(S) | 8. PERFORMING ORGANIZA- T. R. Metcalf | TION REPORT NO: F. M. Friedlaender | |------------------------------- -----------------------------------------------|10. WORK UNIT NO. 9. PERFORMING ORGANIZATION NAME AND ADDRESS | Lockheed Martin Missiles and Space |------------------------------- Advanced Technology Center, O/L9-41, B/252 |11. CONTRACT OR GRANT NO. 3251 Hanover Street, Palo Alto Ca. 94304 | NAS8 - 40801 -----------------------------------------------|------------------------------- 12. SPONSORING AGENCY NAME AND ADDRESS |13. TYPE OF REPORT AND Marshall Space Flight Center (Explorer Program)| PERIOD COVERED Huntsville Alabama 35812 | Progress report for the month Contact: Larry Hill | of February 2000 |------------------------------- |14. SPONSORING AGENCY | CODE MSFC / AP32 -----------------------------------------------|------------------------------- 15. SUPPLEMENTARY NOTES ------------------------------------------------------------------------------- 16. ABSTRACT The SOLAR-A Mission is a program of the Institute of Space and Astronautical Science (ISAS), the Japanese agency for scientific space activity. The SOLAR-A satellite was launched on August 30, 1991, to study high energy phenomena in solar flares. As an international cooperative agreement, Lockheed, under NASA contract, is providing a scientific investigation and has prepared the Soft X-ray Telescope (SXT), one of the two primary experiments of the mission. --------------------------------------|---------------------------------------- 17. KEY WORDS (SUGGESTED BY | 18. DISTRIBUTION STATEMENT AUTHOR(S)) Solar-A, X-ray, CCD, | Space Science, Solar Physics ------------------------|-------------|----------|-----------------|----------- 19. SECURITY CLASSIF. | 20. SECURITY CLASSIF. | 21. NO OF PAGES |22. PRICE (OF THIS REPORT) | (OF THIS PAGE) | | None | None | 7 | ------------------------|------------------------|-----------------|----------- For sale by: Superintendent of Documents, U.S. Government Printing Office