Page 1 PROGRESS REPORT THE SOLAR-A SOFT X-RAY TELESCOPE (SXT) PROGRAM (CONTRACT NAS8-37334) (for the month of October, 1992) OVERVIEW 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 << Solar Activity and Observation Planning >> In October, Robert Willson of Tufts University visited with J. Lemen and K. Strong to explore the possibilities of a joint collaboration between VLA and Yohkoh observations. Dr. Willson returned to Tufts with several SXT partial and full frame images for data taken between 1-May and 10-May-92. A Flare Workshop was held at Hawaii during the week of 2-Nov. The workshop chose to study the 15 November and 24 October 1991 flares because they were quite well observed by Yohkoh and Mees. Individuals who had worked on these flares and representing all of the Yohkoh instruments as well as other sources of data and interpretation gathered for 3 days here at the Institute for Astronomy for the purpose of informally comparing notes on our findings. Both of these flares gave evidence of early and gradual heating and motion of the neutral line filament. Both also had a period of erratic hard x-ray production in advance of the impulsive phase, provided a series of impulsive hard x-ray spikes and an extended period of hard x-ray production following the impulsive phase. The November flare produced dramatic ejecta in both H-alpha and soft x-rays while the October flare appeared to be fully contained. Both flares had a 2- footpoint structure at the most intense hard x-ray spikes and a looptop flare structure in hard x-rays at other times. It was evident from the SXT images and the Mees magnetograms that there were sometimes magnetic connections between the acceleration site(s) and remote locations even though most of the released energy found its way into the primary hard x-ray loop. Page 2 << Data Analysis Software >> On 6-Nov the Yohkoh Software and Database User's Guide was released. The 132 page TEX document covers all aspects of the Yohkoh software and data and is meant as an introduction to analyzing Yohkoh data. A mission summary of the Yohkoh software and database accomplishments are: *. All Yohkoh data from launch to present has been reformatted and distributed to all Yohkoh co-investigator institutions. *. An IDL software package is available to view and analyze all four Yohkoh instruments. The package will run under a VMS or Unix platform. It is installed at over 20 different institutions. *. A comprehensive, multivolume Yohkoh Software and Database User's Guide was written by the LPARL SXT team. *. A standard Yohkoh database is available with Yohkoh data including: - observing log - event log - spacecraft pointing history with two second resolution - spacecraft ephemeris information. *. A standard SXT database for the whole mission is available with: - reference dark images throughout the mission - optical transmission and sun disk location on the SXT CCD - x-ray synoptic images. *. Ground based data has been incorporated into the Yohkoh database including: - GOES event logs - NOAA active region logs - GOES one minute averages light curve data - several magnetogram and h-alpha images per day *. SXT personnel have provided extensive software development support for operational planning. These include: - telemetry reformatting and data processing - deep space network (DSN) planning - S/C command upload generation - SXT sequence table archiving Page 3 << Instrument Operations and Health >> On 27 October 1992 between 0430 and 0630 UT a diffuse halo of scattered light appeared in the aspect images and the central brightness of the narrow band image increased by about 6%. The halo only extended to roughly 3 arcmin beyond the normal image and only in the north-south (up-down on the CCD) direction. The leading theory is that this additional light is coming through a hole which has opened up in one of the x-ray mirror entrance filters. This theory will be tested by taking optical exposures with the aspect telescope aperture door closed. At the present level this change has not resulted in any significant impact to the scientific capability of SXT. If the condition substantially worsens it is probable that the thermal load on the x-ray analysis filters may eventually cause light leaks and degradation of the thin filter x-ray images. Note that the shutter is on the CCD side of the filter wheel. The x-ray filters could be protected from constant long exposure to solar heat load by using the diffuser as a shield. This would require more use of the filter wheels than is necessary at present. The sun spot features are still easily resolved even after this artifact appeared. There is no detectable effect in the x-ray images. 1991 1992 Total ------- ------- ------- Number of images taken and received: 126,940 539,167 666,107 << Data Flow >> Data distribution tapes continue to flow out of ISAS. Processing of the data has been interrupted slightly by the reconfiguration of the ISAS mainframe computers. There have also been numerous problems with accessing the NEC processed spacecraft attitude data (ADS files). These problems are being worked but are taking longer than they should. 1991 1992 Total ------- ------- ------- Total gigabytes distributed: 7.8 38.9 46.7 << Problems >> The sensitivity of the SXT aspect sensor continues to degrade and is still at less than 15% of original. The rate of decay is slowing down as can be seen by a semi-log plot of the transmission. A new problem appeared on 27-Oct in the visible light SXT images. The details are described in the "Instrument Operations and Health" section. Page 4 << Personnel Travel >> The staffing at ISAS for October was: ACTON 1-OCT-92 * 23-OCT-92 23 (total of 23 days) FREELAND 5-OCT-92 30-OCT-92 26 (total of 26 days) HUDSON 1-OCT-92 * 4-OCT-92 4 7-OCT-92 31-OCT-92 * 25 (total of 29 days) NITTA 6-OCT-92 31-OCT-92 * 26 (total of 26 days) MARTENS 1-OCT-92 * 31-OCT-92 * 31 (total of 31 days) SLATER 7-OCT-92 31-OCT-92 * 25 (total of 25 days) WUELSER 1-OCT-92 * 5-OCT-92 5 (total of 5 days) The plans for staffing ISAS for November are: ACTON 18-NOV-92 30-NOV-92 * 13 (total of 13 days) HUDSON 1-NOV-92 * 3-NOV-92 3 18-NOV-92 30-NOV-92 * 13 (total of 16 days) LEMEN 10-NOV-92 27-NOV-92 18 (total of 18 days) NITTA 1-NOV-92 * 2-NOV-92 2 9-NOV-92 12-NOV-92 4 19-NOV-92 30-NOV-92 * 12 (total of 18 days) MARTENS 1-NOV-92 * 16-NOV-92 16 (total of 16 days) SLATER 1-NOV-92 * 9-NOV-92 9 19-NOV-92 30-NOV-92 * 12 (total of 21 days) LEKA 3-NOV-92 23-NOV-92 21KLIMCHUK 6-NOV-92 m is due to a pin hole in 2. Focus on resolving the discrepancies in the SXT camera gain determination. 3. Continue the Data Analysis and Reduction software development effort. 4. Continue mission operations and data analysis at ISAS. Respectfully submitted, Mons D. Morrison Frank Friedlaender Page 5 -------------------------------------------------------------------------------- UNIVERSITY OF HAWAII ACTIVITY REPORT (DR. R. CANFIELD) MAJOR ACTIVITIES FOR THE MONTHS OF SEPTEMBER AND OCTOBER Our most important Yohkoh activities were Yohkoh operations, Mees operations, data analysis and software development in Hawaii and Japan, and preparation for the Hawaii workshop The Mees observers continued full-day observations in support of Yohkoh. Hudson supported SXT operations in Japan, and Mickey, Leka, Metcalf, Wuelser, and Canfield served as Yohkoh Duty Scientist in Hawaii. The observers obtained magnetograms with both the Stokes Polarimeter and the new Imaging Vector Magnetograph. They obtained MCCD Imaging spectra and coronal limb videos in H-alpha. The most noteworthy observations were those of AR 7321 in late October, including an X flare on October 30. Hudson's major effort involved the use of the HXT as a spectrometer. In October he received the initial calculations of spectral response from the HXT team, and he is incorporating these into IDL software that can be used generally. There are two immediate applications: first, for the Hawaii workshop; and second, for the study of "impulsive footpoints". Hudson submitted an abstract to the AAS meeting in Phoenix on the subject of impulsive footpoints. The Bacflare was submitted to Solar Physics. Mickey worked on various hardware and software upgrades to the IVM. Measurements were made to characterize the IVM spectral drift. Mickey and Leka installed the new IVM fold mirror mounts and a new liquid-crystal shutter. Mickey, Metcalf, and Leka got the new IVM H-alpha flarewatch program running, in coordination with the observers, and Metcalf wrote preliminary software to read the data tapes. Mickey completed an analysis of the system optical aberrations, as a guide to the telescope optics vendor. Metcalf continued analyzing currents and X-ray structures in AR6952. He is currently working on the final co-alignment of the Mees and Yohkoh data and has started writing up the results. Metcalf worked with Jiao on the study of the height dependence of the chromospheric magnetic field using Na-D data. They are currently analyzing the extent to which the chromospheric and photospheric field is force-free. Metcalf, Canfield, Wuelser, and Hudson worked on various aspects of the 1991 October and 24 flares in preparation for the workshop here in early November. He analyzed AR7260 IVM and Stokes data for Nariaki Nitta, and July 13, 1992 Stokes data for Andrzej Fludra. Page 6 Wuelser spent most of September at ISAS. During his visit he wrote a program (HXA_SUNCENTER) which calculates the SXT suncenter position from the HXA data. He also worked with members of the HXT team on the HXT data for the events of 1991 October 24 and 1992 July 16. In preparation for the upcoming workshop in Hawaii, de la Beaujardiere, Hudson, and Wuelser worked on the flare of 1991 October 24. Wuelser analyzed the early phase of the event in terms of the chromospheric evaporation model. Leka performed initial evaluations of the data from the Imaging Vector Magnetograph for NOAA 7260. This initial analysis has led to recommendations of changes to the standard observing program in the future when such a large sunspot (almost 1' in diameter) is being observed. In addition, this analysis quickly pointed out some shortcomings of the standard observing sequence, which will be most easily accommodated when the Fabry-Perot stabilization has been completed. PLANS FOR NOVEMBER AND DECEMBER Support of the Yohkoh and Mees operations will continue by Hudson, the Mees observers, and the Yohkoh duty scientists. The IVM will return to active region magnetograms early in November. It will continue to be operated in this mode most of the time, with continued short interruptions for hardware upgrades, which will be. carried out by Mickey, Leka, and Waterson. During November 3 - 5 we will hold the coordinated data analysis workshop on the 1991 October 24 and November 15 flares at the Institute for Astronomy. Metcalf will wrap up the AR6952 study, and to continue to work with Jiao on the height dependence of the magnetic field using a combination of Na-D and FeI magnetograph data. Metcalf and Jaio will complete the study of the extent to which the field is force-free and then study the use of the Na data to resolve the 180 degree ambiguity in the photospheric Fe-line magnetograms. Metcalf will also begin the analysis of the IVM H-alpha data from the flarewatch program. Wuelser will finish his work on the flares of 1991 November 15, and 1991 October 24. He will continue the analysis of the 1992 July 16 flare. Leka will work on currents and magnetic flux emergence in AR7260 in Japan in November. She will incorporate the images of AR7260 from SXT into the analysis of the current-carrying properties of the active region as significant flux emerged, and utilize the images to interpret the connectivity of the region. She will also visit NAOJ and Hida Observatory. Hudson will continue to work on spectral interpretation of the HXT data, with a possible extension to its application in the imaging data. He intends to extend the HXT spectral analysis to include thermal sources, up to "superhot" temperatures, and also to study SXT response to power-law spectra. Hudson has several other science projects under way, including active-region development studies with Leka and Metcalf, coronal observations with several people, studies of the expanding active-region loops observed by SXT (collaboration with Y. Uchida), and studies of meter-wave phenomena. Canfield will work on the 1992 July 16 flare in collaboration with other members of the Yohkoh team. Page 7 -------------------------------------------------------------------------------- UNIVERSITY OF CALIFORNIA AT BERKELEY MAJOR ACTIVITIES FOR THE MONTHS OF SEPTEMBER AND OCTOBER During this reporting period, the effort at UC Berkeley consisted of the analysis of Yohkoh and other correlated solar flare data relevant to the presentation of Yohkoh-related papers at the following meetings: (1) Symposium on Fundamental Problems in Solar Activity, 29th meeting of COSPAR, Washington, D.C., (2) Compton (Gamma Ray Observatory) Symposium, St. Louis. Missouri, and (3) Yohkoh Workshop Kane. The paper for the Hawaii Workshop will be presented by McTiernan. The following paper was completed and submitted for publication in the Advances in Space Research: "Spatial and Spectral Characteristics of the X-ray Sources in the 15 November 1991 Solar Flare", S. R. Kane et al. Terry Slocum, an undergraduate student at UC Berkeley, participated in the analysis of the Yohkoh and other correlated data. He is expected to complete a small research project before his graduation. Page 8 -------------------------------------------------------------------------------- STANFORD UNIVERSITY (DR. P. STURROCK) MAJOR ACTIVITIES FOR THE MONTHS OF SEPTEMBER AND OCTOBER Our Yohkoh-related activities during the past two months were as follows. Peter Sturrock visited ISAS during the last week of October. George Roumeliotis attended the Sac Peak Workshop on Image Processing, where he presented his recent work on sharpening SXT images using the maximum entropy method. Taeil Bai began to examine SXT data corresponding to surge events observed in H-alpha at Big Bear Solar Observatory. Jim Klimchuk submitted a paper for the Proceedings of the SOHO Workshop on Coronal Streamers, Coronal Loops, and Solar Wind and Coronal Abundances. The paper is entitled "Static and Dynamic Loop Models and Their Observational Signatures," and although it is concerned mostly with UV spectroscopic observations, it has relevance to broad-band soft X-ray observations such as those from SXT. We intend to step up our Yohkoh-related activities considerably over the next few months. Sturrock will attend the Yohkoh meeting on the October 23, 1991 and November 15, 1991 flares, which will be held in Hawaii during the first week of November. Klimchuk will visit ISAS for approximately three weeks beginning November 7, and he plans to devote the majority of his time to the analysis of Yohkoh data when he returns. Sturrock and Bai will continue their study of surges, and Roumeliotis will continue to develop image enhancement techniques. Page 9 -------------------------------------------------------------------------------- SOLAR PHYSICS RESEARCH CORPORATION (KAREN L. HARVEY) MAJOR ACTIVITIES FOR THE MONTHS OF SEPTEMBER AND OCTOBER Activity these last two months has focussed on several areas: (1) Compilation of a bibliography of SXT/Yohkoh papers published. The SXT bibliography consists of three lists: (1) papers published in referred journals, (2) papers presented at scientific meetings (listed by meeting), and (3) papers published in general science publications. In addition to maintaining the bibliography in Tucson, it also resides on sxt3 in Palo Alto for access by Lockheed individuals: located in /usr/people/harvey/sxt.bibliography. This will be updated periodically. (2) Organization of a collaborative observing program between Yohkoh SXT instrument and the NSO/KP magnetograph. Objective of this effort was to obtain high temporal and spatial resolution PFI observations of Bright Points to determine the scale of BP intensity and structural variations. Requested are 2 x 2 full-resolution map, 5x5 arcmin area, a time resolution of 32 seconds, and maximum exposure of 5 seconds. Coordinated magnetic field observations are to be taken by NSO/KP spectromagnetograph. The dates selected for the initial effort were October 19 and 20, 1992. It unfortunately was cloudy both days at Kitt Peak, and the Sun became too active to consider these quiet Sun, long exposure observations. The program was postponed until the a more quiet period of activity. (3) Discussions with Keith Strong on next phase of study of BPs. This includes the development of a detailed plan of research using current data to sample during the more than one year of operation of Yohkoh. We are considering the specific properties and methods of analysis of the data to determine time variation in the counts of BPs, their association with magnetic fields, lifetimes, temperatures, temporal variations. Page 10 -------------------------------------------------------------------------------- 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 | November 10, 1992 October 1992 |-------------------------------- | 6. PERFORMING ORGANIZATION | CODE: O/91-30 -----------------------------------------------|-------------------------------- 7. AUTHOR(S) | 8. PERFORMING ORGANIZA- M. D. Morrison | 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 Jan, 1992 |-------------------------------- |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 | 10 | ------------------------|------------------------|-----------------|------------ For sale by: Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402-0001 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ No. Delivered From Subject Lines 2 Oct 30 19:32 POSTMAN [From: >> Thursday, Nov 12, 1992 12:34 PM PST