PROGRESS REPORT THE SOLAR-A SOFT X-RAY TELESCOPE (SXT) PROGRAM (CONTRACT NAS8-37334) (for the month of January 1994) 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 from Kagoshima Space Center (KSC) in Japan, and renamed Yohkoh. The purpose of this mission is to study high energy phenomena in solar flares. Under an international cooperative agreement, Lockheed, 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 by Lockheed in cooperation with the National Astronomical Observatory of Japan, and the Institute for Astronomy of the University of Tokyo. MAJOR ACTIVITIES IN THE MONTH The Lockheed team has updated and enhanced the Yohkoh Analysis Guide. It has been distributed to the user community. Preliminary reports indicate that it is a useful tool, especially for first time users of Yohkoh data since it covers all of the instruments. Lockheed has initiated a new overhead accounting system in 1994. It is too early to evaluate the effects, but the 533M's will provide detailed data. Operations are normal with no significant events, although refinements in the operational procedures are almost a weekly occurrence. << Solar Activity and Observation Planning >> The Sun started January 1994 in a state of high activity but the level of flaring has slowly dropped throughout the month to less than 20% of the level in late December. The Sun produced ten M-level flares during the month, several of which were well observed by the Yohkoh instruments. The active region that has been responsible for most of the recent, large flares has returned on three successive rotations (NOAA AR7622, 7640, 7654). It has changed significantly since the last transit. The main sunspot has clearly grown in area but the overall complexity of the region has simplified. There are fewer and smaller satellite sunspots. The equivalent coronal structure has also simplified and has reduced its X-ray emission. However, at the end of the month this region started a new phase of growth and produced several large flares as it set behind the west limb. There is a new small region (AR7658) emerging in the dark coronal hole that is trailing AR7654. This is how this flare-productive region was originally formed so this new area of emerging magnetic field is worth following as it could develop into a similar region over the next few solar rotations. The coronal hole situation may be related to damage suffered by Canadian communications satellites, according to Vic Gaizauskas and Dave Speich. This damage occurred simultaneously on two "Anik" spacecraft on about 20 January. The presence of strong emission of >2 MeV (relativistic) electrons would be the prime suspect if this were the case, via spacecraft charging effects. We will see what happens on the next passage of the January hole. It is predominantly in the South, which is favorable for Ulysses observations. << Observation Planning and Campaigns >> Observation planning was shared between L. Acton, H. Hudson, and N. Nitta in January. We continued our weekly offpoints to take deep exposures of the extended X-ray corona. An X-ray bright campaign was organized for 20 January. While some trial images were taken the campaign had to be canceled as there was a large flare-productive region returning over the east limb. The campaign with HIRES (G. Timothy, Stanford) is postponed until September 1994. L. Acton's special flare table for measuring the SXT mirror scatter during a flare was successfully run and observed at least 2 flares. << Science Progress>> At LPARL preparations for the spring meeting of the AGU continue to be made. K. Strong is one of the liaison people between the AGU and AAS/SPD. He is organizing the "remote sensing" session with Ed Reolof at Johns Hopkins. G. Linford and K. Strong were visited by M. Neugebauer (JPL) to initiate a collaboration between Yohkoh and Ulysses looking at the origin of the high- speed solar-wind modulation seen by Ulysses as it moved to higher latitudes. We are preparing for upcoming visits by J. Gosling who is proposing to investigate other aspects of Ulysses/Yohkoh joint observations. Leon Golub is visiting next month to continue a joint analysis of the NIXT and Yohkoh data. Y. Ogawara, R. Canfield, and K. Strong attended the IACG workshop that was held in Easton, MD, on 27-29 January 1994. They made a joint presentation of recent results from Yohkoh to the workshop that comprised a mixture of solar and heliospheric scientists representing existing and future observational capabilities from ISAS, NASA, ESA, and IKI. The workshop broke up into four groups to look at existing data that might be relevant to the many outstanding problems in these fields and plan future collaborations between the various teams. K. Strong was appointed the leader of the group studying the 3-D structure of large-scale coronal features. A draft report was written at the workshop which will be circulated to the participants and any other interested party. Three campaign periods were identified for the next year: 1) SPARTAN flight in September 1994 2) the South polar passage of Ulysses (max: ~December 1994) 3) the rapid transit of Ulysses from the south to northern poles of the Sun (mid 1995) At ISAS, G. Slater worked chiefly on synoptic maps. N. Nitta continued his study of AR 7260 flares. Shibata and Nitta studied X-ray jets in association with active region development. Kurokawa and his students at Kyoto visited, analyzing the data that was taken during the Hida campaigns. Outside ISAS, there were several correspondences among different people, trying to identify the problem that present alignment software locates an SXT white light flare a few SXT pixels away from the peak hard X-ray source. These discussions will continue. There was significant science progress focusing on AR 7260 (the region of interest at the Hawaii CDAW, Dec. 93). Canfield worked with Shibata (NAOJ) and his students on moving blue-shifted features seen in the MCCD dopplergrams, in connection with the emerging-flux-driven reconnection model. Shimizu (Univ of Tokyo) and Nitta had a short session on how to locate X-ray microflares on the MCCD continuum images. Lidia van Driel-Gesztelyi (Univ. of Tokyo) made her monthly visit to ISAS and worked with Nitta on the draft of a paper on flares along the sheared inversion line, also examining flares in the emerging flux region in detail. Apart from AR 7260, Hudson discussed hard X-ray emission above the soft X-ray loop with its discoverer S. Masuda. The M flare of 28 Jan. gave us another good look at what appeared to be a "precursor" in the GOES plots. The search for such precursors was a main part of Franta Farnik's research when he visited ISAS last year. Jan. 28 was a good example, because SXT was locked onto the active region in ARS2 to carry out the special scattering program. As with the few events that Farnik found, this "precursor" turned out to be remote (but in the same complex of activity) from the subsequent flare, which was definitely not a re-brightening of preheated loop structure. D. Alexander continued work on Alfven wave particle acceleration, investigating the possible connection between gamma ray emission and soft X-ray nonthermal line widths for SMM flares. He has drafted a paper describing this work. He began work suggested by Hugh Hudson on characterizing the 3-D geometrical effects on SXT images of X-ray coronal loops. There follows a list of publication activity by members of the Yohkoh SXT teams for this reporting period that features or includes SXT data. This list is incomplete as not all of the teams were able to respond to this new feature of the monthly report in time. -- Papers Submitted -- "Yohkoh Observations of Active Regions and Filaments" K. Strong, proceedings of the 2nd SOHO workshop, Elba, Italy. "GENERAL STRUCTURE OF THE X-RAY CORONA", L. Acton, invited review to be published in the Proceedings of IAU Colloquium 144 on "Structure of the Solar Corona". "LONG DURATION EVENTS IN MAGNETIC ARCADES AND LARGE LOOPS", A. Fludra, J. Jakimiec, M. Tomczak, J. L. Culhane and L. W. Acton, to be published in the proceedings of the symposium "New Look at the Sun with Emphasis on Advanced Observations of Coronal Dynamics and Flares", Kofu, Japan "Implications of Coronal Abundance Variations" J. Saba and K. Strong, to be published in the proceedings of the symposium "New Look at the Sun with Emphasis on Advanced Observations of Coronal Dynamics and Flares", Kofu, Japan "Evidence for Both Electron Acceleration and Direct Heating in Solar Flares", B. Dennis, G. Holman, H. Hudson, T. Kosugi, K. Strong, and D. Zarro, to be published in the proceedings of the symposium "New Look at the Sun with Emphasis on Advanced Observations of Coronal Dynamics and Flares", Kofu, Japan "Observations of the Structure and Dynamics of Coronal Loops" K. Strong, to be published in the proceedings of the symposium "New Look at the Sun with Emphasis on Advanced Observations of Coronal Dynamics and Flares", Kofu, Japan "Studying the 3-D structure of Large Scale Coronal Features" (K. Strong et al.). Chapter 3 of IACG report on Easton Workshop. "Combined HRTS-8 Sounding Rocket and Yohkoh Observations of NOAA Active Region 7260 at the solar Limb", C.M. Korendyke, K.P. Dere, G.E. Brueckner, K. Waljeski, and J.R. Lemen. Kofu, Japan -- Papers Accepted for Publication -- "The 9 November 1991 Flare at 03:20 UT: Observations from Yohkoh" G. Doschek, J. Mariska, K. Strong, R. Bentley, C. Brown, J. Culhane, J. Lang, A. Sterling, and T. Watanabe, Ap. J. "High Energy Gamma Ray Emission from Solar Flares: Constraining the Proton Spectrum", D. Alexander, P.P. Dunphy and A.L. MacKinnon, Solar Phys. -- Papers Published -- "The 1992 January 5 Flare at 13:30 UT: Observation from Yohkoh" G. Doschek et al. with K. Strong, L. Acton, M. Bruner, H. Hudson, T. Metcalf, J.-P. Wuelser, Ap. J. 416, 845, 1993. - Presentations Given -- "A Review of Yohkoh SXT Observations" G. Linford, M. Morrison, S. Freeland, G. Slater, and J. Lemen, Fall AGU, San Francisco, 1993 "Explosions on the Sun: the enigma of solar flares" D. Alexander, MSU Physics Colloquium, January 1994 "Principal Results from Yohkoh" Y. Ogawara, R. Canfield, and K. Strong, IACG workshop in Easton, MD, 27-29 January 1994 -- Abstracts Submitted -- "Creation and Heating of Inter-region Coronal Loops" B. Handy, AGU, May 1994. "Non-thermal soft X-ray line broadening in gamma ray flares" D. Alexander, COSPAR 1994. "SXT Observations of Active Regions and their Evolution" K. Strong, COSPAR 1994. "Coordinated SPDE, Yohkoh, and Ground-based Observations of an Emerging Flux Region and Filament" L. Dame, M. Bruner, R. Shine, T. Tarbell, and K. Strong, COSPAR 1994. << Public Use of SXT Images >> G. Linford and K. Strong produced another two articles for Sky & Telescope including SXT images. Their first article was published in the January issue. It was well received by Sky & Telescope and they are considering expanding the solar coverage in future. We continue to receive many requests for the Lockheed-produced SXT posters, public relations prints, and video tapes for educational purposes. G. Linford made an improved version of the partial solar eclipse image. This image was put into show_pix (by H. Hudson), and copies of it were sent to Loren Acton and Bill Wagner. He also sent K. Phillps copies of the Mercury transit and Solar Eclipse images for two different European journals. << Computer Software and Hardware >> The machines at ISAS are now in the process of having their firmware upgraded. The software for IDL V3.5.1 and their appropriate license packs have been installed on all of the ISAS machines. Much of our effort for this month was focused on completing the "Yohkoh Analysis Guide", which was organized by M. Morrison and J. Lemen. Just about everybody on the SXT team participated by writing, revising, or checking sections of this 300+ page document. Lockheed has printed 150 copies and distributed them to the various Co-I groups, ISAS, and SDAC. The demand is so heavy for these that we are going to print another 75 copies. << Spacecraft and SXT Operations and Health >> Yohkoh continues to function well and has an expected orbital life of about 10 years. No major subsystem has failed in the first 29 months of operation. All the Yohkoh instruments continue to produce scientifically interesting data as the Sun evolves towards solar minimum. During recent operations both the BCS and SXT have experienced a normal level of single event upsets (SEUs). The SXT SEUs were found on: SXT bit map error: 940109 pass 1 and recovered on that pass SXT 'IVD ML' error: 940117 pass 1 and recovered on next pass SXT 'WRM' error: 940120 pass 3 and recovered on the next pass SXT bit map error: 940125 pass 1 A CCD warm-up was successfully completed on 10-12 January to prevent the buildup of contaminants on the cooled CCD. Page ?? << Data Flow >> ------------------------------------------------------------------------------ Month Full Frame Images Observing Region Images Received Lost Received Lost Loss % QT FL Tot Sep-91 517 397 21174 3541 24715 5481 18.15 Oct-91 4106 2532 6393 12437 18830 3401 15.30 Nov-91 5291 2475 12149 14696 26845 10952 28.98 Dec-91 4896 3190 5001 16837 21838 6892 23.99 Jan-92 5544 3177 10084 5972 16056 6849 29.90 Feb-92 5305 2803 16932 11382 28314 12019 29.80 Mar-92 6248 2361 20367 2653 23020 9458 29.12 Apr-92 6734 3500 20094 5423 25517 12390 32.69 May-92 7032 3158 25464 4589 30053 13745 31.38 Jun-92 6937 3112 23307 13221 36528 12627 25.69 Jul-92 6345 3275 23941 10510 34451 14717 29.93 Aug-92 6572 2978 24207 11154 35361 13550 27.70 Sep-92 6087 2916 26832 20042 46874 15729 25.12 Oct-92 6743 2589 50985 14709 65694 23687 26.50 Nov-92 6658 2939 24416 14696 39112 12924 24.84 Dec-92 6747 3027 24147 6600 30747 12495 28.90 Jan-93 6888 3351 24067 4861 28928 13069 31.12 Feb-93 6833 3004 24479 18149 42628 12302 22.40 Mar-93 7177 3460 25874 19537 45411 14657 24.40 Apr-93 7754 3644 34128 8352 42480 17967 29.72 May-93 8571 3950 41832 7518 49350 21971 30.81 Jun-93 7340 2589 64545 12539 77084 26299 25.44 Jul-93 8259 3650 47561 5352 52913 24213 31.39 Aug-93 7628 3638 30705 3563 34268 17436 33.72 Sep-93 6875 2899 22697 5600 28297 11252 28.45 Oct-93 7474 3657 33782 7548 41330 20104 32.72 Nov-93 8353 4015 42180 5849 48029 24669 33.93 Dec-93 5898 3047 21128 13297 34425 13001 27.41 Jan-94 3347 1253 12735 3946 16681 5463 24.67 Feb-94 0 0 0 0 0 0 NaN Total 184159 86586 761206 284573 1045779 409319 28.13 Number of Full Frame Images Received: 184159 Number of Observing Region Images Received: 1045779 Total: 1229938 Approximate Number of Shutter Moves/CCD Readouts: 2176238 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. << 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 (%) Oct-91 31.07 21.3 509 261 10.5 77.8 Nov-91 31.06 20.9 648 277 11.9 64.4 Dec-91 31.04 20.2 804 353 14.0 52.5 Jan-92 31.13 23.6 985 450 0.5 / 2 14.9 38.4 Feb-92 31.32 30.8 1176 544 14.3 31.7 Mar-92 31.47 36.5 1355 626 14.8 25.1 Apr-92 31.44 35.2 1323 610 23.8 / 4 14.6 22.8 May-92 31.65 43.1 1417 653 14.4 20.1 Jun-92 32.12 60.9 2215 880 -2.5 / 3 15.1 17.4 Jul-92 32.22 64.4 1852 832 15.5 14.1 Aug-92 32.21 64.1 1922 886 14.9 13.1 Sep-92 32.38 70.5 2062 954 -1.2 / 3 15.9 12.2 Oct-92 32.64 80.3 2317 1055 16.8 11.5 Nov-92 36.24 215.1 6112 1391 18.0 11.0 Dec-92 42.58 452.8 17390 2024 17.9 N/A Jan-93 42.59 453.1 13006 2034 23.8 / 2 19.2 N/A Feb-93 42.28 441.5 13895 2090 17.7 N/A Mar-93 43.14 473.8 14047 2151 17.7 N/A Apr-93 43.13 473.4 14304 2146 23.8 / 2 16.9 N/A May-93 43.45 485.3 16405 2357 17.3 N/A Jun-93 44.03 507.2 20037 2531 16.3 N/A Jul-93 44.52 525.6 23977 2700 22.5 / 2 17.7 N/A Aug-93 44.24 515.0 21879 2643 25.2 / 3 17.2 N/A Sep-93 45.07 546.2 27469 2745 17.5 N/A Oct-93 45.40 558.6 31684 2982 17.7 N/A Nov-93 45.31 554.9 31892 3224 23.8 / 3 19.7 N/A Dec-93 45.92 578.1 38515 3101 19.2 N/A Jan-94 46.32 592.9 44730 3651 22.5 / 2 21.7 N/A Feb-94 N/A N/A N/A N/A 0.0 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. << Personnel Travel >> -- SXT travel for the month of January 1994: -- SXT Foreign Travel between 1-JAN-94 and 31-JAN-94 List was Generated: 7-Feb-1994 14:58:50.00 PR_TRAV_SUMM Ver 1.0 29-Apr-92 ACTON 31-JAN-94 31-JAN-94 * 1 (total of 1 days) HUDSON 1-JAN-94 * 5-JAN-94 5 17-JAN-94 31-JAN-94 * 15 (total of 20 days) NITTA 1-JAN-94 * 23-JAN-94 23 (total of 23 days) SLATER 4-JAN-94 31-JAN-94 * 28 (total of 28 days) LABONTE 5-JAN-94 31-JAN-94 * 27 (total of 27 days) CANFIELD 17-JAN-94 31-JAN-94 * 15 (total of 15 days) ---------------------------------------------------------------- Grand Total of 114 days for 6 people NOTE: The "*" signifies travel that actually ends after 31-JAN-94 In addition to these scheduled operations trips Keith Strong and Dick Canfield attended the IACG meeting in Easton, MD. Keith Strong stayed on at GSFC to work with the SPARTAN and SERTS teams in early February. Hugh Hudson left ISAS for Washington DC to attend the AAS meeting << Planned SXT travel for the month of February 1994: >> SXT Foreign Travel between 1-FEB-94 and 28-FEB-94 List was Generated: 7-Feb-1994 16:07:45.00 PR_TRAV_SUMM Ver 1.0 29-Apr-92 ACTON 1-FEB-94 * 28-FEB-94 * 28 (total of 28 days) HUDSON 1-FEB-94 * 28-FEB-94 * 28 (total of 28 days) LINFORD 7-FEB-94 28-FEB-94 * 22 (total of 22 days) SLATER 1-FEB-94 * 3-FEB-94 3 (total of 3 days) LABONTE 1-FEB-94 * 28-FEB-94 * 28 (total of 28 days) CANFIELD 1-FEB-94 * 11-FEB-94 11 (total of 11 days) ---------------------------------------------------------------- Grand Total of 120 days for 6 people NOTE: The "*" signifies travel that actually ends after 28-FEB-94 Respectfully submitted, Keith Strong Frank Friedlaender Page ?? -------------------------------------------------------------------------------- UNIVERSITY OF HAWAII ACTIVITY REPORT (DR. R. CANFIELD) No Input Required for this month -------------------------------------------------------------------------------- UNIVERSITY OF CALIFORNIA AT BERKELEY (DR. S. KANE) No Input Required for this month -------------------------------------------------------------------------------- STANFORD UNIVERSITY (DR. P. STURROCK) No Input Required for this month -------------------------------------------------------------------------------- SOLAR PHYSICS RESEARCH CORPORATION (KAREN L. HARVEY) No Input Required for this month -------------------------------------------------------------------------------- MONTANA STATE UNIVERSITY (LOREN ACTON) No Input Required for this month -------------------------------------------------------------------------------- Page ?? -------------------------------------------------------------------------------- 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 February 1994 January 1994 |-------------------------------- | 6. PERFORMING ORGANIZATION | CODE: O/91-30 -----------------------------------------------|-------------------------------- 7. AUTHOR(S) | 8. PERFORMING ORGANIZA- K. T. Strong | TION REPORT NO: F. M. Friedlaender | |-------------------------------- -----------------------------------------------|10. WORK UNIT NO. 9. PERFORMING ORGANIZATION NAME AND ADDRESS | Lockheed Palo Alto Research Labs B/252 |-------------------------------- Solar & Astrophysics Laboratory O/91-30 |11. CONTRACT OR GRANT NO. 3251 Hanover Street, Palo Alto Ca. 94304 | NAS8 - 37334 -----------------------------------------------|-------------------------------- 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 | of January 1994 |-------------------------------- |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 | 11 | ------------------------|------------------------|-----------------|------------ For sale by: Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402-0001