Page 1 PROGRESS REPORT THE SOLAR-A SOFT X-RAY TELESCOPE (SXT) PROGRAM (CONTRACT NAS8-40801) (for September 1997) 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, 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 Palo Alto Research 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 As we await the request for proposal (RFP) to be issued by MSFC, we are making preparations to respond to allow continued operations in 1998. An improved file server/computer for use in Japan at ISAS to replace an aging NASA owned machine will be proposed to help streamline operations and to improve efficiency and redundancy. << Solar Activity >> In early September, solar activity was moderate, with an M1.0 on Sept. 8. Yohkoh observed the decaying phase of the M1.0 flare. There were as many as six active regions at one time, and the largest sunspot area went up to more than 600 millionths. During the first half of the month, the GOES level did not drop below B level, with a steady progression of high-latitude regions. There were 24 flares classed at C level and above. In the latter half of September, solar activity continued to be moderate. The GOES X-ray level was at mid-B level. Most of the activity came from regions 8084 and 8085 as they rotated around the W limb during mid September. The most notable events were two M class flares on Sept. 17 in AR 8084. In late September most of the activity came from region 8088. It produced two M-class flares, and numerous C-class flares. The M5.9 and M3.0 flares both happened on Sep 24 during Yohkoh nights. Observations of several of the C-class flares were obtained, among them a long duration event that was probably associated with the halo CME observed by SOHO. Page 2 At the end of the reporting period solar activity remained moderate, with activity seen in three main regions: 8088, 8090, 8091. No flares above GOES C class were seen, though aurorae were reported over Atlanta, Georgia. 3 C-class events were observed. One (C2.6) was observed on AR8088 on 29 Sep 97 (UT). Others (C1.0) were observed on 28 Sep 97 and on 2 Oct 97, respectively. An interesting feature was the apparent (though uncertain) interaction between active regions on opposite sides of the solar equator. << Campaigns >> SXT participated in several campaigns during September. During Sep. 8-12 SXT participated in an X-ray bright point observation scheduled also by SOHO and ground-based observatories (L. McDonald, A. Fludra). The timing of the campaign was a bit unfortunate because of the moderate activity, which kept us from doing detailed coverage during the invisible orbits. Nevertheless SXT got excellent data on each of the XBP's selected by SOHO. SXT ran a special program to observe X-ray jets with Shimojo-san. The purpose was to obtain a high time resolution sequence of a jet producing region in two filters (Al.1 and Al12). Half resolution PFI's at fixed pointing with relatively short fixed exposures were used. Ideally, one would observe for two real-time orbits in PFI dominant mode, but this was not possible due to the moderately high activity level of the sun. The coordinated SOHO - Tenerife campaign on Chromospheric Activity and Filaments ran from 25-September through 5-October. It was organized by Brigitte Schmieder. Special SXT observations of the campaign target were not possible due to the high activity. The HRTS rocket flew on Sep. 30, and Yohkoh was put into "campaign mode" to protect the data. The launch time had been coordinated so that in fact Yohkoh was in daylight and clear of the SAA at the time of the flight. At present we do not have the data in hand from DSN, nor do we know any details of the rocket flight, so we are hoping that things went well. Observations were obtained of active regions 8090, 8091, to support the ASP observing run at Sac Peak from October 1 through October 12, looking for separator geometry during active region evolution. Organizers were Metcalf and Pevtsov. During the period October 4-11 we ran a program to examine the possible influence of shutter position on Al.1 straylight, at the request of Acton, Metcalf, and Freeland. << Science >> Acton created a very nice 6 year, daily average light curve for the SXT AlMg filter (http://www.space.lockheed.com/SXT/html2/Dagwood_6yr_lite_curv.html) Page 3 showing the long-term variation of X-rays detected by SXT. Metcalf finished re-reducing IVM data from 1996 June 6 for a collaboration with Dana Longcope and George Fisher on their SOHO JOP. The re-reduction is necessary due to the great improvement in the IVM reduction software by Don Mickey and Barry LaBonte. He also used MDI data from June 6 to coalign the IVM data with CDS images. The coalignment is very good. Metcalf and Alexander continued work on a paper comparing the MEM and pixon reconstruction algorithms for HXT. Alexander generated psuedo-data which Metcalf and Kosugi are in the process of analyzing. Nitta Re-analyzed SXT and MCCD data for one flare in AR 7260, and confirmed that a cancelling feature seen several hours before may be responsible for the flare. He also analyzed data for a large scale structure within AR 7260, in order to learn where a long duration event started. This LDE seemed to start more than an hour before a compact flare in the emerging flux region, but its brightness appeared to increase significantly around the time of the latter flare. However, it is still my impression that the two events were independent in the sense that one of them could have occurred without the other. Nitta prepared SXT images for a CME's on 23/24 Sep and 27 September on the occasion of a NASA press release. Wuelser prepared a new draft of the paper on Yohkoh pointing and the Mercury transit observations, co-authored by Hudson, Kosugi, Masuda, Morrison, and Nishio. << 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 Lockheed SXT WWW homepage (http://www.space.lockheed.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 September were 37482 accesses and 1228 Mbytes transferred. << Yohkoh Operations and Health >> Yohkoh and the SXT continue to function very well. There has been no further increase in stray light since 25 August 1996. SXT experienced a normal level of Single Event Upset (SEU) events during the month: SXT bit map error 22-Sep-97 Pass 2: 970922-0207 recovered in the same pass. SXT wrm reset error 25-Sep-97 Pass 1: 970925-0412 recovered in the 2nd pass. SXT bit map error 29-Sep-97 Pass 1: 970929-0101 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 Jun-95 305822 131019 1295287 347777 1643064 641088 27.76 Jul-95 6418 4145 21180 1639 22819 15109 39.84 Aug-95 7683 2597 26115 2181 28296 10537 27.13 Sep-95 6546 2853 22006 1753 23759 10433 30.51 Oct-95 6937 3502 22177 3853 26030 13044 33.38 Nov-95 5745 2944 21252 517 21769 12119 35.76 Dec-95 6163 2615 24059 901 24960 11652 31.83 Jan-96 6474 2530 27015 1708 28723 14151 33.01 Feb-96 6200 2581 21380 890 22270 10773 32.60 Mar-96 6908 2869 25437 1460 26897 12274 31.33 Apr-96 7172 2124 45445 671 46116 18848 29.01 May-96 6925 2426 30272 1089 31361 12367 28.28 Jun-96 7515 2723 31952 1536 33488 14521 30.25 Jul-96 5954 1995 29886 4769 34655 12427 26.39 Aug-96 7214 3010 21187 1607 22794 9887 30.25 Sep-96 6904 2618 29906 303 30209 12663 29.54 Oct-96 7405 2853 16463 1842 18305 8034 30.50 Nov-96 7001 2296 24292 5395 29687 9340 23.93 Dec-96 7144 2643 25331 2087 27418 10412 27.52 Jan-97 7186 2747 21126 1257 22383 9915 30.70 Feb-97 6016 2034 22097 1072 23169 8961 27.89 Mar-97 7152 1300 26991 1209 28200 6394 18.48 Apr-97 6018 1055 23639 3890 27529 5349 16.27 May-97 7703 1455 29574 3783 33357 7121 17.59 Jun-97 7706 1522 25786 1396 27182 7908 22.54 Jul-97 8614 1385 32503 431 32934 6559 16.61 Aug-97 7316 987 23136 3519 26655 4990 15.77 Sep-97 3409 489 18406 2401 20807 3187 13.28 Oct-97 0 0 0 0 0 0 0.00 Total 489250 193317 1983900 400936 2384836 920063 27.84 Number of Full Frame Images Received: 489250 Number of Observing Region Images Received: 2384836 Total: 2874086 Approximate Number of Shutter Moves/CCD Readouts: 5027932 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 (%) Jul-95 49.34 706.2 106408 6628 18.1 N/A Aug-95 49.72 720.4 114414 7101 19.5 N/A Sep-95 49.79 723.1 115165 7222 19.6 N/A Oct-95 50.29 741.9 126452 7911 20.2 N/A Nov-95 50.11 735.1 122163 7814 25.2 / 2 20.3 N/A Dec-95 50.19 737.9 123705 7927 22.6 N/A Jan-96 50.81 761.3 136197 8888 21.5 N/A Feb-96 50.67 755.8 133263 8705 22.5 / 2 21.5 N/A Mar-96 50.85 762.9 136982 8973 20.3 N/A Apr-96 51.14 773.6 142250 9500 19.9 N/A May-96 51.16 774.4 140697 10018 19.1 N/A Jun-96 51.56 789.2 147705 10634 20.7 N/A Jul-96 57.45 1010.2 146293 12228 19.8 N/A Aug-96 52.58 827.5 165676 12393 19.6 N/A Sep-96 52.47 823.3 162784 12350 20.0 N/A Oct-96 52.21 813.8 157689 12047 22.5 / 2 21.3 N/A Nov-96 52.45 822.9 161683 12534 21.9 N/A Dec-96 53.08 846.2 171224 13860 22.9 N/A Jan-97 52.35 818.9 164785 11354 23.8 / 7 23.3 N/A Feb-97 51.95 803.9 159426 10346 21.1 N/A Mar-97 55.99 955.6 158428 12190 21.2 N/A Apr-97 53.14 848.4 176207 13265 20.8 N/A May-97 52.96 841.7 172052 13094 20.7 N/A Jun-97 53.69 869.0 182460 14849 19.8 N/A Jul-97 54.44 897.3 184518 20173 22.5 / 2 21.1 N/A Aug-97 54.06 883.1 188485 15549 20.1 N/A Sep-97 54.71 907.4 195430 17625 21.3 N/A Oct-97 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. Page 6 << Personnel Travel >> SXT Foreign Travel between 1-SEP-97 and 30-SEP-97 HUDSON 1-SEP-97 * 14-SEP-97 14 29-SEP-97 30-SEP-97 * 2 (total of 16 days) LEMEN 30-SEP-97 30-SEP-97 * 1 (total of 1 days) MCKENZIE 26-SEP-97 30-SEP-97 * 5 (total of 5 days) NITTA 1-SEP-97 * 3-SEP-97 3 (total of 3 days) SAVY 1-SEP-97 * 30-SEP-97 * 30 (total of 30 days) WUELSER 3-SEP-97 30-SEP-97 28 (total of 28 days) ---------------------------------------------------------------- Grand Total of 83 days for 6 people NOTE: The "*" signifies travel that actually ends after 30-SEP-97 SXT Foreign Travel between 1-OCT-97 and 31-OCT-97 CANFIELD 25-OCT-97 31-OCT-97 * 7 (total of 7 days) HUDSON 1-OCT-97 * 22-OCT-97 22 (total of 22 days) LEMEN 1-OCT-97 * 9-OCT-97 9 (total of 9 days) MCKENZIE 1-OCT-97 * 31-OCT-97 * 31 (total of 31 days) SAVY 1-OCT-97 * 31-OCT-97 * 31 (total of 31 days) SLATER 2-OCT-97 31-OCT-97 * 30 (total of 30 days) ---------------------------------------------------------------- Grand Total of 130 days for 6 people NOTE: The "*" signifies travel that actually ends after 31-OCT-97 Respectfully submitted, Thomas R. Metcalf James R. Lemen Page 7 7 ================================================================= Montana State Univ Activity Report for August 1997-September 1997 ================================================================= (L. W. Acton) The Very Big News in the MSU Solar Physics Group is that grad student Meredith Wills passed her comprehensive exams, and her orals. We are also happy to welcome a new member to the team, Aaron Benner, who will take over the task of computer systems administrator. The MSU Solar Physics Group was involved in a great variety of activities during August and September, and far-flung as many of us took our respective acts on the road. Loren Acton traveled to Costa Rica, where he gave a talk on "Cell Adhesion in Microgravity" to the Association of Space Explorers. Dick Canfield traveled to Sac Peak, where he presented a review on the "Helicity of Solar Magnetic Fields;" he also spent two weeks as Duty Scientist at Mees Observatory. Alex Pevtsov went to Marshall Space Flight Center for a week, to study the data reduction procedure of their vector magnetograms. Dana Longcope returned to Montana during this term, after spending the summer at UC Berkeley working with George Fisher. Charles Kankelborg and grad student Brian Handy both traveled to Goddard Space Flight Center for TRACE testing, and the TRACE meeting. Handy also went to Idaho State University, where he gave a talk, and then to MSU for a week. At the end of September, David McKenzie traveled to Japan to spend two months at ISAS working on SXT operations. Some of the MSU group was involved in teaching, or gave other talks in addition to the few mentioned above. Acton is teaching the Texts & Critics course under the MSU Honors Program; Longcope is teaching Plasma Physics in the MSU physics department. Longcope also attended a three-day workshop on The Undergraduate Physics Curriculum, and served as advisor for a host of new students. McKenzie gave a talk on "Current Events in the Solar System" to an association of medical doctors. Canfield, in addition to speaking at the NSO annual summer meeting, also presented a review of solar magnetic helicity to the Relativity/Astrophysics Seminar to the MSU physics department. Kankelborg wrapped up teaching the Physics 101 course in August. We hosted a number of visitors to Montana during the last two months. We were honored to be visited by Igor Zhitnik in early August. Dr. Zhitnik is from the Lebedev Institute near Moscow; he presented a discussion of XUV imaging spectroscopy techniques. We were happy to host Tom Metcalf and Sam Freeland, who are working with Acton on the SXT movie. And we were visited by Kevin Reardon, who completed a paper with Canfield during his stay. Additional collaborations with scientists at other institutions included: Acton is working with Jing Li of the Center for Astrophysics, in the analysis of SXT full disk images to be used in deriving temperatures within the lower parts of streamers; McKenzie is working with Y. Suematsu (Mitaka Observatory), Y. Hanaoka (Nobeyama Observatory), and H. Kurokawa (Hida Observatory), on an examination of the relationship between zipper arcades and eruptive prominences; Handy is working with Karel Schrijver on the Quiet Sun campaign, and a topological study of Page 8 bright points; Handy spent some time working with Marilyn Bruner on thin film recipes for use in UV. Pevtsov has been working with Sergei Latushko (ISTP, Russia) on the helicity of large-scale magnetic fields. Closer to home, Pevtsov has been studying HSP and ASP magnetograms in a study of the stability of local helicity areas in active regions, and with Canfield and undergraduate Sean Sandborg has been studying large-scale coronal structures. Longcope, Kankelborg, and Pevtsov submitted a SOHO-GI proposal. Pevtsov finished modifying the CD-ROM writing procedures in IDL, and undergraduate Jen Greenfield has been copying data tapes to CD-ROM. Grad student Mark Weber is pushing forward in his research on differential rotation; as a component of this, Weber is working to understand the sources of uncertainty in the production of SFD images from SXT. Handy spent time working on a paper discussing hardware used on TRACE; Kankelborg has been working on TRACE observing sequences, and TRACE automatic exposure controller (AEC) testing sequences. Kankelborg is also striving to produce a validated sequence logic test for TRACE. Canfield handled the advertisement of, and the receipt of applications for, the systems administrator/research scientist position; he has begun conducting interviews for that position. Canfield & Pevtsov have also put time into organizing the Chapman conference "Magnetic Helicity in Laboratory and Space Plasmas," to be held in Boulder next summer. Proposals to NASA and to NSF have been made for partial funding for that conference. Acton has written a description of the Super-X high-resolution telescope, in preparation for the Solar-B announcement of opportunity. Finally, we have prepared some scientific publications and other writings. Acton performed some revisions to his paper on spectral irradiance derived from SXT data, after recalculating some results. Longcope submitted a contribution to proceedings of the "High Resolution Solar Atmospheric Dynamics Workshop" (and was invited to referee two papers for ApJ). Kankelborg et al's paper, "Observation and Modeling of Soft X-ray Bright Points II. Determination of Temperature and Energy Balance," was accepted by ApJ (to appear in the 20-dec-97 issue). Pevtsov & Longcope submitted the paper "NOAA AR 7926: A Kinked Omega-Loop?" to ApJ, and Pevtsov & Canfield submitted the paper "On the Origin of Helicity in Solar Active-Region Magnetic Fields" to ApJ Letters. Canfield & Reardon completed a paper on tether cutting and twist transfer before the 15-nov-91 solar flare; and Canfield was invited to review a few papers for ApJ and A&A. Weber finished a revision of the "SXT Chief Observer's Handbook," which is currently being field tested by McKenzie. McKenzie, Tim Slater, and grad student Michelle Larson wrote a large set of lesson plans for educators, which are now online at the YPOP website, and are currently being classroom tested. ======================================================================= Univ of Calif, Berkeley Activity Report for August 1997-September 1997 ======================================================================= (J. McTiernan) The Yohkoh work here at UCB in the past two months has concentrated on Page 9 the calculation of Differential Emission Measures (DEM) for soft X-ray flares, using the SXT and BCS detectors. A paper is being written, and will be submitted for publication this month. Some of the results can be seen on the web at http://sprg.ssl.berkeley.edu/~jimm/spd97.html We are presently looking at the Neupert effect as it relates to plasma of different temperatures. J. McTiernan is collaborating with Mike Wheatland and Vahe Petrosian of Stanford on a project involving the data analysis of impulsive soft X-ray footpoint sources. At present there are 42 good candidates for impulsive SXR sources; we are now making HXT images and spectra for the events to compare with the SXT images, to whittle the sample down to a more manageable size (20 flares or so). McTiernan is also collaborating with John Mariska of NRL on a study of partially occulted flares. This will involve spectral analysis using HXT and possibly BATSE data. ============================================================= Univ of Hawaii Activity Report for August 1997-September 1997 ============================================================= (B. LaBonte) Our activities included support of Yohkoh operations and data analysis at ISAS, coordinated ground-based data acquisition (including designated Yohkoh campaigns) at Mees, collaborative analysis of Yohkoh/Mees data, and preparation of manuscripts. Operational support for SXT was provided by Nitta at Mees and LaBonte in Manoa. Our colleagues Jiao and Mickey at Manoa, Canfield at Montana State University, Wuelser and Metcalf at Lockheed, and Hudson at Solar Physics Research Corporation aided in advice and oversight of Mees operations. Don Mickey has returned to solar work full time as of September after a year of half time devoted to other projects. A power glitch on September 2nd put the White Light and POI instruments out of service. The White Light camera has been repaired and returned and should be in operation in early October. The parts for the POI are on order. There were also successes in instrument operation. The IVM had small optical and electronic failures but was repaired and realigned and is providing excellent data. The MCCD shutter problem was resolved and normal operations will resume once Reni Kupke completes her thesis observations in October. Good vector magnetogram coverage of some of the flaring active regions in September was obtained. Page 10 LaBonte is working with Mickey and K.D. Leka (SEL) on the comparison of IVM and APS observations of vector fields. The preliminary data indicate a better match than any of the previous magnetograph intercalibrations. Improved methods for deriving the field parameters from the Stokes spectra are being tested, to make the analysis more model independent. ============================================================ Stanford Univ Activity Report for August 1997-September 1997 ============================================================ (M. Wheatland) Solar flares represent an outstanding unsolved puzzle in astrophysics. It is a remarkable observational fact that the statistics of flares bear close resemblance to the statistics of earthquakes and avalanches: all of these diverse natural phenomena follow power-law size distributions, and in each case there is no correlation between the time between events and the size of the ensuing event. These correspondences have motivated the use of avalanche models, based on the ideas of self-organized criticality, to describe flares. The cellular automata of these models successfully reproduce the observed distributions of solar flare energy, peak flux and duration, but they lack a firm physical basis. For the model to be soundly based, the hypothetical automaton field, and the rules for its evolution, must be identified with physical properties and processes in an active region on the Sun, where flares occur. The automaton field has variously been attributed to the magnetic field of an active region, the magnetic vector potential, and the magnetic free energy. The redistribution rules are generally associated, imprecisely, with magnetic reconnection - the energy release mechanism often assumed to underlie flaring. The details remain unclear, however. For example, a necessary feature of automata fields is the existence of a local conservation law, that preserves the field during redistribution events. In the sand-pile models which provide a paradigm of self-organized criticality, the conserved quantity is the number of grains of sand. In solar flare avalanche models, little thought has been given to what is being conserved. Another worrying aspect of the avalanche models of flares is the use of three-dimensional automata, when the physics of active regions is essentially two-dimensional, with transport and MHD processes constrained to follow the magnetic field lines of active region loops. We are left in the unsatisfactory situation of having a successful model with a shaky theoretical foundation. Mike Wheatland has begun a theoretical examination of the avalanche picture, aimed at providing a sound physical basis to the model. Sang-Hyun Kim, a research student working with Peter Sturrock and Mike Wheatland, is investigating a loop structure in a quiet coronal region observed by Yohkoh SXT during the interval 3-15 May 1992. Previous studies (Sturrock, Wheatland & Acton, 1996, ApJ, 461, L115; Wheatland, Sturrock & Acton, 1997, ApJ, 482, 510-518) assumed that the magnetic field is essentially open, and used a conserved-heat-flux form for the temperature variation. They then found the temperature and energy flux at Page 11 the coronal base which produce the best fit to the data. In this new study, we will consider the possibility that the region comprises a closed loop. We use the coronal loop model of Vesecky, Antiochos and Underwood (1979, ApJ, 233, 987-997). The temperature along the loop is calculated numerically and fitted with the same data as above. An initial result shows that the uniform energy input assumption in the model does not produce a good fit. Sang-Hyun is currently examining how nonuniform energy input varies the fit result, with the goal of determining whether any form of the energy input provides a satisfactory fit. Clare Parnell has completed an article on Coronal Heating by Nanoflares and Microflares. She has examined data concerning the convergence and cancellation of magnetic features, and coordinated the data with a model for these processes. She has then combined the output from these calculations with a particular model for the formation and dissipation of current sheets in the corona, and so obtained an estimate of the energy release rate associated with the convergence and cancellation of magnetic features. These calculations indicate that this combination of processes could yield sufficient energy to explain coronal heating in the quiet Sun. Clare has since left our group to return to St Andrews, Scotland, to work in Eric Priest's solar theory group. We wish her well in her new position, and look forward to ongoing collaborations with her. Papers accepted: Wheatland, M. S. & Glukhov, S. "Flare Frequency Distributions Based on a Master Equation," to appear in ApJ 494 Walther, G. "Absence of Correlation Between the Solar Neutrino Flux and the Sunspot Number," to appear in Phys. Rev. Lett. =========================================================================== Solar Physics Research Corp. Activity Report for August 1997-September 1997 =========================================================================== (Karen L. Harvey and Hugh S. Hudson) KAREN L. HARVEY: Activities for August and September: (1) Work on finalizing the programs for identifying and isolating coronal holes in the synoptic rotation maps of He I 10830 and magnetic fields. These routines have been used to produce the final maps of the locations the boundaries of coronal holes during Carrington rotations 1892--1894 for a comparative study with models of the regions of open and closed fields and the Ulysses and Wind data for this period (paper with Marcia Neugebaurer and others that resulted from the coronal hole workshop held in Bern, Switzerland in July 1996; this paper will be Page 12 submitted for publication within the next few weeks). A poor mismatch between some of the the boundaries of coronal holes and the modeled open fields as well as the location of open field where no coronal hole was detected prompted a reexamination of the He I 10830 data. The boundaries of the He I 10830 coronal holes were confirmed; most of the discrepancies between the models and observations appears to be related to the low-resolution magnetic data used in the model calculations; these data missed opposite polarity intrusions of magnetic flux. (2) Continuation a comparison with Hugh Hudson and Loren Acton of the filament cavities observed by the SXT on June 21, July 4, and July 18, 1997 with the NSO/KP photospheric and chromospheric magnetograms and He I 10830 spectroheliograms. Preliminary conclusion is that the boundaries of the filament channel observed in He I 10830 correspond to the edges of the X-ray cavity. Prepared and submitted a paper on filament channels in He I 10830, H-alpha and X-ray cavities for the IAU Colloquium 167 on New Perspectives on Solar Prominences. (3) Preparation of NSO/KP full-disk magnetograms and He I 10830 spectroheliograms for SXT investigators for studies of the magnetic field and He I 10830 structures associated with X-ray structures. Planned Activities for October and November: Activities for October and November will be to continue the analysis of the data from the several XBPs campaigns and completion of first in a series of planned papers on X-Ray Bright Points; to continue the analysis of the history of the activity complex 7958/7978, the evolution of its fields and connections by comparing the magnetic field, He I 10830 and SXT observations, and the producing drafts of the next two papers planned on this work. Work also will be started on producing coronal hole maps for the Yohkoh period. Publications: K. L. Harvey and V. Gaizauskas, 'Filament Channels: Contrasting Their Structure in H-alpha and He I 1083 nm', in D. Webb, B. Schmieder, D. Rust (eds.), IAU Colloquium 167, ASP Conference Proceedings, in press, 1997. HUGH S. HUDSON Activities in August and September: Hudson attended the TRACE workshop at GSFC and the ESLAB31 symposium at ESTEC. At the latter he helped several people with SXT data and showed off recent filament and CME observations. Fortunately, the GRL special-issue deadline was postponed to October 15, so there is a chance for a Yohkoh paper on events associated with halo CMEs to actually make it. He also worked on a draft Nature letter on Sakao's footpoint Page 13 separation observations, and also drafted his ESLAB31 papers. Other Hudson activities included SXT support, specifically efforts to get the stray-light corrections improved via the use of the terminator images. He continued to work with organizational activities in preparation for the 2nd SOHO/Yohkoh CDAW, on active regions. The TRACE workshop was productive and suggested some operational links in the likely eventuality that Yohkoh will work together closely with TRACE observing plans during the initial part of the TRACE mission (now scheduled for December but likely to be a month or two later; at last report the launch vehicle was working pretty well). Plans for October and November: Hudson must devote the first two weeks of October entirely to paper-writing, not counting Yohkoh duties - ESLAB manuscripts, the Sakao footpoint paper, and the GRL special issue paper. After that the top priority will be following up on the filament cavity and related observations of June through August. The images have excited a lot of interest wherever they have been shown. It appears that the EIT and LASCO data will provide interesting insights to this structure too. The second SOHO/Yohkoh data analysis workshop will take place in October. Hudson should attend, but not may not because of excessive travel. There is in fact a strong Yohkoh contingent who will attend. Paper submitted: Plunkett, S. P., Gopalswamy, N., Kundu, M. R., Howard, R. A., Thompson, B. J., Gurman, J. B., Lepping, R. P., Hudson, H. S., Nitta, N., Hanaoka, Y., Kosugi, T., and Burkepile, J. T., ESA SP-404, (1997). Page 14 ------------------------------------------------------------------------------- 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 October 1997 September 1997 |------------------------------- | 6. PERFORMING ORG | CODE: O/H1-12 -----------------------------------------------|------------------------------- 7. AUTHOR(S) | 8. PERFORMING ORGANIZA- T. R. Metcalf | TION REPORT NO: J. R. Lemen | |------------------------------- -----------------------------------------------|10. WORK UNIT NO. 9. PERFORMING ORGANIZATION NAME AND ADDRESS | Lockheed Palo Alto Research Labs B/252 |------------------------------- Solar & Astrophysics Laboratory O/H1-12 |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 | of September 1997 |------------------------------- |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 | 14 | ------------------------|------------------------|-----------------|----------- For sale by: Superintendent of Documents, U.S. Government Printing Office