Page 1 PROGRESS REPORT THE SOLAR-A SOFT X-RAY TELESCOPE (SXT) PROGRAM (CONTRACT NAS8-40801) (for November 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 The RFP for FY 98 operations still has not been released. We have received a "Notice on Intent to Exercise Option No.3". This is the third option in the present contract but covers Data Analysis only. There does seem to be considerable effort at MSFC to get the RFP released soon, however. << Solar Activity >> In early November, solar activity picked up again with the spectacular AR 8100. AR 8100 grew rapidly in to a delta configuration and produced two X class flares. The first was on November 4 at 0530 UT and the second was on November 6 at 1155 UT. The November 6 flare was the strongest solar flare since Oct-Nov 1992. "Super region" AR 8100 continued through mid-November and raised the X-ray background level from B to mid-C, displayed numerous M flares, and two X-flares (X2 and X9). Type II radio bursts and elevated fluxes of energetic electrons and protons were noted. SXT got many images in the second X flare in several filters. Later in the month, the GOES 1-8 A background decreased to a low B level as AR 8100 rotated off the west limb. At least two regions emerged (AR 8106 and 8107), with major flare activity seen in AR 8103 and 8108, both located in the northern hemisphere. AR 8108, in particular, was predicted to produce CMEs (Pat McIntosh), and indeed the C4.6 flare of 14-NOV-97 09 UT was an LDE and very eruptive. This region was located just to the south of a non-polar coronal hole and continued to grow. Page 2 In late November, the GOES 1-8 A background level fluctuated between A6 and B2, largely reflecting the evolution of AR 8108. We had several C class flares, two of which were apparently from the region -- they were quite eruptive. This region also showed nice loop structures even in Be images. AR 8113 grew steadily. It produced many C and M class flares, and on Thanksgiving Day an X class flare. When we caught the rising phase, we saw plasma ejections in the larger field of view SXT images. The return of AR 8100, now called AR 8112, was not very active. << Campaigns >> In November, the only organized campaign was the SERTS 1997 flight on 18 November UT. SXT supported this campaign by protecting 20 minutes worth data for simultaneous coverage. We had planned to run a routine sequence during the SPARTAN observations, but did not due to the problems with the SPARTAN. Later in the month, an attempt to observe X-ray jets was marred by a flare that started right after the table upload. << Science >> Acton continued to work with Jing Li on temperature analysis of 25-Jul-96 west limb corona for comparison with coronagraphic measurements. For this work Acton wrote sxt_eff_area.pro to conveniently extract the SXT spectral response, taking get_yo_dates into account. Alexander continued work on analysis the Whole Sun Month Yohkoh data. In particular, concentrating on checking the temperature analysis which gives radial temperature profiles of the quiet solar corona. Interestingly, these profiles are distinctly different to those found by Acton for the diffuse corona during the active part of the cycle. McKenzie did some analysis of the 6-Nov X9 flare, mostly concerning flare temperatures. He looked into (and didn't find) the effect of two X flares on the SXT dark-frame signal. Nitta analyzed data from the X2.9 flare on Thanksgiving Day. The SXT flare sequence in quarter resolution images nicely showed the trajectory of the plasma ejection. Wuelser's paper entitled "Precise Determination of the Coordinate Systems for the Yohkoh Telescopes and the Application of a Transit of Mercury" by Wuelser, Hudson, Nishio, Kosugi, Masuda, and Morrison has been accepted for publication in Solar Physics. << Public Use of SXT Images >> We are continuing to make Yohkoh/SXT images available for a variety of uses. Page 3 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 60667 accesses and 2155 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 wrm reset error 17-Nov-97 Pass 1: 971117-0204 recovered in the 3rd pass. Page 4 << Data Flow >> Month Full Frame Images Observing Region Images Received Lost Received Lost Loss % QT FL Tot Thru Aug-95 319923 137761 1342582 351597 1694179 666734 28.00 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 7051 1479 33646 9596 43242 8887 17.05 Oct-97 7023 1134 26813 1827 28640 6043 17.42 Nov-97 1846 437 6938 7358 14296 2203 13.35 Dec-97 0 0 0 0 0 0 0.00 Total 501761 195878 2032891 417316 2450207 934009 27.60 Number of Full Frame Images Received: 501761 Number of Observing Region Images Received: 2450207 Total: 2951968 Approximate Number of Shutter Moves/CCD Readouts: 5155671 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 (%) 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 54.77 909.7 196501 17757 21.0 N/A Oct-97 54.85 912.8 198157 17857 21.5 N/A Nov-97 55.05 920.3 199862 18776 21.3 N/A Dec-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-NOV-97 and 30-NOV-97 CANFIELD 1-NOV-97 * 7-NOV-97 7 (total of 7 days) HUDSON 1-NOV-97 * 4-NOV-97 4 16-NOV-97 30-NOV-97 * 15 (total of 19 days) MCKENZIE 1-NOV-97 * 24-NOV-97 24 (total of 24 days) NITTA 1-NOV-97 30-NOV-97 30 (total of 30 days) SAVY 1-NOV-97 * 30-NOV-97 * 30 (total of 30 days) SLATER 1-NOV-97 * 20-NOV-97 20 (total of 20 days) WEBER 20-NOV-97 30-NOV-97 * 11 (total of 11 days) ---------------------------------------------------------------- Grand Total of 141 days for 7 people NOTE: The "*" signifies travel that actually ends after 30-NOV-97 SXT Foreign Travel between 1-DEC-97 and 31-DEC-97 ACTON 29-DEC-97 31-DEC-97 * 3 (total of 3 days) HUDSON 1-DEC-97 * 13-DEC-97 13 19-DEC-97 31-DEC-97 * 13 (total of 26 days) SAVY 1-DEC-97 * 31-DEC-97 * 31 (total of 31 days) WEBER 1-DEC-97 * 20-DEC-97 20 (total of 20 days) ---------------------------------------------------------------- Grand Total of 80 days for 4 people NOTE: The "*" signifies travel that actually ends after 31-DEC-97 Respectfully submitted, Thomas R. Metcalf Frank Friedlaender Page 7 7 ================================================================= Montana State Univ Activity Report for October 1997-November 1997 ================================================================= (L. W. Acton) MSU ACTIVITY REPORT FOR OCTOBER/NOVEMBER 1997 RESEARCH: Pevtsov spent two first weeks in the Sacramento Peak Observatory observing with the Advanced Stokes Polarimeter. It happens to be a part of the observational campaign "Separator models of Coronal Loops". Kankelborg revised the TRACE AEC tables, online documentation, and AEC software simulator. As a result, AEC now works! Charles also: -produced validation run summaries for all Sept/Oct instrument sequence tests -Made many corrections to sequences/frames for 30-day science plan -Wrote one new polar observation sequence -Rewrote TRACE flare sequences. Acton spent a considerable amount of time helping Jing Li at Harvard with analysis of SXT data from the time of the rocket coronagraph experiment of 25-Jul-96. For this work he wrote sxt_eff_area.pro to conveniently extract the SXt spectral response, taking get_yo_dates into account. Canfield finished a review of vector-magnetograph current helicity measurements and submitted it for the proceedings of the NSO summer meeting. McKenzie worked on a paper on filament motion near a suspected reconnection site, with Y. Suematsu. Brian Handy spent quite a lot of time working with EIT and MDI data, and put a couple of huge movies on-line. He summarizes: "For those with bandwidth to burn, there are two nice ones: 1. A movie of only EIT data during the EIT-MDI high cadence campaign (7 minutes/image, 256x256 pixels, centered on the MDI hi-res field of view:) http://www.space.lockheed.com/SXT/movies/EIT-MDI-970810.html 2. The same EIT movie with the MDI data contoured over the top. Contours are +/- 50 Gauss. This is a great observation for an active region study, unfortunately I was hoping to spend more time looking at the quiet sun in the lower half of the image. I will prevail, however: http://www.space.lockheed.com/SXT/movies/EIT-MDI-COMP-970810.html Page 8 The MDI data has been binned down to EIT resolution to cut the size to something useable. I'm currently working with Mandy Hagenaar to track magnetic flux bits around in the photosphere. These two movies are the fastest/longest movies of the corona I think I've seen. (e.g. fastest over this long a time span.) Kudos to Sam Freeland who wrote the IDL software to generate these movies." SXT OPERATIONS: Acton analyzed (negative) results of test of shutter position on Al.1 darkframes -- report posted to show_pix/calibration/Thin_AL_darkframe_test. Acton also prepared and published (show_pix/calibration/DARKFRAME_STATISTICS) short report on statistical properties of darkframe signals. McKenzie spent October and November at ISAS, learning to be Chief Observer; and also spent one week as SSOC Tohban. Canfield served a week as SSOC Tohban. At the end of November, Weber traveled to ISAS to act as SXT Chief Observer. TALKS GIVEN: At Sac Peak, Pevtsov gave a colloquium on "NOAA 7926: a kinked, Omega-loop?" McKenzie gave a seminar on "Periods in SXT Light Curves" at ISAS, and again at Kyoto University. Canfield presented the following talks: "The Eruptive Flare of 15 November 1991: Preflare Phenomena" Solar Journal Club, MSU / Bozeman, Oct 1. "The Involvement of Foreign Researchers in ISAS Mission Planning, Implementation and Ensuing Scientific Accomplishments", Invited Talk, Evaluation Working Group on Space Science Projects, Space Science Subcommittee of the Advisory Committee on Art and Science of the Ministry of Education, Science, Sports and Culture, Tokyo, Oct 28. "The Eruptive Flare of 15 November 1991: Preflare Phenomena" Yohkoh Seminar, ISAS, Sagamihara, Japan Oct 30. "Magnetic Fields on the Sun: Kinky Business" (invited), Applied Mathematics Colloquium, Department of Mathematics, MSU/Bozeman, November 20. PUBLICATIONS: The paper, "Yohkoh Soft X-ray Determination of Plasma Parameters in a Polar Coronal Hole" by C. A. Foley, J. L. Culhane, and L. W. Acton is in press for the December 20, 1997, issue. The paper, "Nitric Oxide Abundance in the Mesosphere/Lower Thermosphere Region: Roles of Solar Soft X Rays, Suprathermal N(4S) Atoms, and Vertical Transport" by Transport" by P. K. Swaminathan, D. F. Strobel, D. G. Kupperman, C. Krishna Kumar, L. Acton, R. DeMajistre, J. -H. Yee, L. Paxton, D. E. Anderson, D. J. Strickland , and J. W. Duff has been accepted for publication in JGR(Space). "Helicity of Solar Active-Region Magnetic Fields", Richard C. Canfield Page 9 and Alexei A. Pevtsov, NSO Meeting on Synoptic Solar Physics, K. S. Balasubramaniam, J. Harvey, and D. Rabin, editors. (submitted) "UV Observations with TRACE", Handy et al., submitted to Solar Physics. OTHER BUSINESS: MSU's proposal to link up with the vBNS (very-high bandwidth NSF science net) has been accepted for funding. This will link us up to the world with a T3 (45 Mbps) line -- hopefully within 6 months or so. Acton served 2 weeks as "visiting scientist" to American Indian e-mail caucus, taught Texts & Critics course, and participated in pushing along the Orbital Drag-Free Internation Experiment mission. The group enjoyed a visit by Tuck Stebbins for discussions of gravity wave astronomy and helioseismology; we also enjoyed a visit of Dr. Alisdair Davey who will join the MSU solar group as systems manager and research scientist. Acton was interviewed by Billings Gazette about early November aurorae. Canfield and Pevtsov finalized the list of invitees and topics for the Chapman conference "Magnetic Helicity in Laboratory and Space Plasmas", to be held at NCAR next July. Canfield made a presentation as foreign commentator to the the Evaluation Working Group on Space Science Projects, established under the Ministry of Education, Science, Sports and Culture in Japan. Kankelborg revised the MSU TRACE budget, and prepared summaries for contract extensions; developed a pattern recognition algorithm that removes cosmic ray streaks from Yohkoh/SXT images (possibly applicable to TRACE too). ============================================================= Univ of Hawaii Activity Report for October 1997-November 1997 ============================================================= (B. LaBonte) MAJOR ACTIVITIES FOR OCTOBER and NOVEMBER 1997 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. Weather during this interval has been normal for the season. The IVM computer failed during this time. A plan for upgrading the IVM to Page 10 replace the computer was already in place and that work has gone forward. Test observations are in progress. The Stokes Polarimeter continues to take the vector magnetogram survey. Graduate student Kupke finished her PhD thesis observations with the MCCD. That instrument is being switched back to the normal H-alpha spectroscopy program. LaBonte and Chou (Hsing-Hua U.) are extending their work on acoustic imaging of sunspot regions. Time series of acoustic images of the isolated active region AR 7981 are being compared to the Mees vector magnetograms to understand the acoustic imaging process, to see if we can distinguish field orientations by their acoustic signature. ============================================================ Stanford Univ Activity Report for October 1997-November 1997 ============================================================ (M. Wheatland) Stanford Group Yohkoh Report for October and November 1997 Sang-Hyun Kim, a research student working with Peter Sturrock and Mike Wheatland, is continuing his investigation of 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. Kim has identified two or three apparent closed loops in the image, and is analyzing data for those regions in terms of 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. Kim has compared with data with two models: one in which energy is deposited uniformly along the loop, and one in which energy is all deposited at the top of the loop. Kim finds that the latter gives a much better fit to the data than the former. Kim will be pursing this topic further, with a view to determining whether an array of closed loops could be consistent with the diffuse image. Peter Sturrock has begun to study the relationship between soft X-ray emission and other solar indicators, pursuing the analysis presented by Loren Acton at the 9th Coolstar Workshop in Florence in July 1995 (published in the proceedings of that workshop). Acton presented averages of the indicators for 53 Carrington rotations. Sturrock has examined, in particular, the total X-ray flux and the mean Page 11 magnetic field strength. A scatter diagram shows that these indices are clearly correlated, but it does not give a good determination of the index of the power-law relationship between the two. However, a modification of this procedure leads to a much stronger display of the correlation, and a much better determination of the power-law index. The procedure is to order the data by increasing field strength, to form the logarithm of each index, and then normalize the logarithm to have mean value unity. The next step is to form the running sums of each of normalized logarithmic measures. This leads to a closed curve that begins at the origin and ends at the origin. For perfect correlation, the curve would wrap back on itself. For a strict power law, the curve would be a straight line. [This procedure could, incidentally, provide a good test for correlation even when the relationship is not simple in form (such as a power law).] We find that, for the data presented by Acton, this procedure leads to a strong case for a power-law relationship, with index 2. This results appears to be consistent with the "sudden-magnetic-relaxation" model of coronal heating that Sturrock presented at the Bath Yohkoh Conference in 1995. The next step is to see if the correspondence can be made quantitative as well as qualitative. Studies of solar flares have generally examined individual events in great detail. The advent of spacecraft observations of flares in hard and soft X-ray has provided datasets that are naturally suited to statistical examination. Statistical studies have brought a new perspective to flare physics, even motivating a theoretical model of the physical mechanism underlying flares (the avalanche model). Mike Wheatland is conducting an investigation of a particular statistical property of flares - the distribution of times between flares, or waiting times. The motivation for this study is two-fold. First, there has been a variety of evidence presented for sympathetic flaring - the triggering of one flare by another. If this were a real effect, then flares would not be randomly distributed in time - there would be an overabundance of short intervals between flares, by comparison with a random time series. Hence it is possible that the existence of sympathetic flaring may be tested by examining the flare waiting-time distribution. There are three recent attempts to do this in the literature, and all give different answers. The second motivation for examining the waiting-time distribution is that models for the statistics of flares make specific assumptions, or specific predictions, about the waiting-time distribution. The model for flare statistics due to Rosner and Vaiana begins by assuming that flares occur as a Poisson process in time. An examination of the avalanche model for flares reveals that it predicts that the waiting time distribution is exponential, the signature of a Poisson process. For this study Mike Wheatland is using the data from the Interplanetary Cometary Explorer (ICE, formerly ISEE-3) spacecraft, provided by Jim McTiernan at Berkeley. This dataset was chosen because waiting time distributions are strongly biased by data gaps, and Page 12 the ICE was an interplanetary spacecraft, and so does not suffer periodic data gaps. The analysis includes comparison of the observed waiting-time distribution with that from a random process, namely a non-stationary Poisson process with an instantaneous rate estimated from the data. For the rate-estimation step we use a new procedure devised by Jeff Scargle and based on a Bayesian method. Mike Wheatland is preparing a paper on the results of this study. In future work he will look at the Yohkoh flare record, which has the advantage of providing information about where flares occurred. =========================================================================== Solar Physics Research Corp. Activity Report for October 1997-November 1997 =========================================================================== (Karen L. Harvey and Hugh S. Hudson) KAREN L. HARVEY: Activities for October and November: (1) Continuation a study with Hugh Hudson and Loren Acton of the filament cavity observed by the SXT during the 1997 June 4-6, June 21, July 4, and July 18, August 2 limb passages. Comparisons with the NSO/KP photo- spheric and chromospheric magnetograms and He I 10830 spectroheliograms show that: 1. The cavity persists for at least 3.5 rotations, 4 June -- 31 August 1997. 2. It appears as an extended area of low X-ray emission enclosed by overlying X-ray loops, 3. Its maximum height varies with time, 4. The intensity of cavity rim varies on short time scales, 5. During each limb passage, an emission structure is visible within the cavity. On 6 June, this structure has a similar shape and is co-spatial with the prominence, but it extends to a greater height. On 4 July, one rotation later, the emission structure is fully separated from the limb and lies above the prominence; it is more diffuse in appearance than during the previous rotation and has an oval or teardrop shape, 6. The shape and intensity of the emission feature located within the cavity varies on short time scales 7. The cavity is visible at the limb for up to 3 days. In the early June passage, the cavity is visible only as the prominence is crossing the limb 8. The longitudinal extent of visible cavity is ~45 degrees, less than the extent of the associated polarity inversion. These results were presented at the 8th PROM workshop held at National Solar Observatory/Sacramento Peak, 1-3 November 1997. (2) The determination of the coronal hole boundaries for the Yohkoh period Page 13 is now being undertaken using the NSO/KP He I 10830 spectroheliograms and photospheric magnetograms. Near real-time preliminary daily coronal hole maps can be found on the NSO/KP web site: http://argo.tuc.noao.edu:2001/synoptic.html (3) Preparation of NSO/KP full-disk magnetograms and He I 10830 spectro- heliograms for SXT investigators for studies of the magnetic field and He I 10830 structures associated with X-ray structures. Planned Activities for December and January: Activities for December and January will to continue the analysis of the data from the several XBP campaigns and writing 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 begin on comparison of the boundaries of coronal hole determined from the HeI 10830 spectroheliograms with those seen in the Yohkoh/SXT data and on updating the Yohkoh bibliography. Papers submitted: Neugebauer, M., Forsyth, R. J., Galvin, A. B., Harvey, K. L., Hoeksema, J. T., Lazarus, A. J., Lepping, R. P., Linker, J. A., Mikic, Z., Steinberg, J. T., von Steiger, R., Wang, Y.-M., and Wimmer-Schweingruber, R. F.: "The Spatial Structure of the Solar Wind and Comparison with Solar Data and Models", JGR, submitted October 1997. Papers published: Harvey, K. L., Hudson, H. S., "The Formation and Evolution of the Coronal Holes Associated with NOAA Region 7978", T. Watanabe, T. Kosugi, A. C. Sterling (eds.), Kluwer Academic Publishers, Dordrecht, The Netherlands, pp. 315-318 (1997). HUGH S. HUDSON Activities in October and November: H. Hudson attended the ESLAB-97 conference at Noordwijk and heard amazing things about the weather connection to the Sun, also learned some things about the solar wind and particles within it. He and Toni Galvin wrote papers for the conference proceedings. A paper on SXT before-and-after image comparisons for halo CME launchers was also submitted to the GRL special issue on January 6, 1997 event. This paper follows up on the Sterling and Hudson paper on the April 7, 1997 event and looks at about ten similar ones. The pattern is as described by Rust and Kumar: sigmoid preflare structure blows up! Stay tuned for more work on this subject. Page 14 Plans for December and January: The "chewy nougat" filled filament cavity, so clearly observed by SXT on July 4, is being written up. This is interesting of course because we had previously not known about hot condensations around cold filaments. We hope to submit a letter-type paper in early December and to follow it up with more thorough analysis. The deduction of temperatures for the nougat and the cavity is challenging because of the thin Al pinhole problem, but this is being worked out. This is a bit of a race against our friendly SOHO rivals, in this case R. Schwenn perhaps - the EIT and probably C1 observations of the chewy nougat phenomenon are really nice. Another hot current item is the X9 flare of 6 October, 1997. This was (quoting Kosugi approximately) "what HXT was built for", and both HXT and SXT got excellent data. HXT can make H channel images at 0.5 sec cadence, probably with sub-arcsec precision. This is stealing a march on HESSI, we believe, except that Yohkoh cannot do gamma-ray imaging. Do we see a Masuda source? Do we see a photospheric flare? Again, stay tuned please! Papers published: 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). Aschwanden, M. J., Bynum, R. M., Kosugi, T., Hudson, H. S., and Schwartz, R. A.: "Electron Trapping Times and Trap Densities in Solar Flare Loops measured with Compton and Yohkoh", ApJ 487, 936-955 (1997). Hudson, H. S. and Webb, D. A.: X-ray Coronal Ejections, in Geophysical Monographs #99, "Coronal Mass Ejections: Causes and Consequences", N. Crooker, J. Joselyn, and J. Feynman (eds.), p. 27 (1997). Hudson, H. S., LaBonte, B. J., Sterling, A. C., and Watanabe, Te.: "NOAA 7978: The Last Best Old-Cycle Region", in T. Watanabe, T. Kosugi, A.C. Sterling (eds.), Kluwer Academic Publishers, Dordrecht, The Netherlands, pp. 237-244 (1997). Harvey, K. L. and Hudson, H. S.: "The Formation and Evolution of the Coronal Holes Associated with NOAA Region 7978", T. Watanabe, T. Kosugi, A.C. Sterling (eds.), Kluwer Academic Publishers, Dordrecht, The Netherlands, pp. 315-318 (1997). Papers accepted: Sterling, A. C., and Hudson, H. S., "Yohkoh SXT Observations of X-ray `Dimming' Associated with a Halo Coronal Mass Ejection", ApJ (1997). Wuelser, J.-P., Hudson, H.S., Nishio, A. Kosugi, T., and Morrison, M.: "Precise Determination of the Coordinate Systems for the Yohkoh Telescopes and the Application of a Transit of Mercury", Solar Physics (1997). Page 15 Papers submitted: Hudson, H.S., Lemen, J.R., St. Cyr, O.C., Sterling, A.C., and Webb, D.F.: "X-ray Coronal Changes during Halo CMEs", GRL, submitted Oct. 15, 1997. Gopalswamy, N., Hanaoka, Y., Lepping, R. P., Steinberg, S. T., Plunkett, S. Howard, R. A., Thompson, B. J., Gurman, J., Ho, G., Nitta, N., and Hudson, H. S.: "On the Relationship between Coronal Mass Ejections and Magnetic Clouds", GRL, submitted Oct. 15, 1997. Webb, D. F., Cliver, E. W., Gopalswamy, N., Hudson, H. S., and St. Cyr, O. C.: "The Solar Origin of the January 6, 1997 CME and Subsequent Geomagnetic Cloud and Storm", GRL, submitted 1997. Watari, S., Watanabe, T., Acton, L. W., and Hudson, H. S., "Limb Events Observed by Yohkoh and Coronal Mass Ejections: A Filamentary Soft X-ray Structure on 5 October 1996", 5th SOHO workshop, Oslo June 1997. Galvin, A. B. and Hudson, H. S., "An Overview of IACG Campaign 4: Solar Sources of Heliospheric Structure Observed out of the Ecliptic", ESLAB-97 (1998). Hudson, H. S. and Galvin, A. B.: "Correlated Studies at Activity Maximum: The Sun and the Solar Wind", ESLAB-97 (1998). Bothmer, V., Posner, A., Kunow, H., M\"uller-Mellin, R., Delaboudiniere, J.-P., Thompson, B., Brueckner, G. E., Howard, R. A., Michels, D. J., Mann, G., Classen, H.-T., and Hudson, H. S.: "Solar Energetic Particle Events and Coronal Mass Ejections: New Insights from SOHO", ESLAB-97 (1998). Svestka, Z., Farnik, F., and Hudson, H. S.: "Post-Flare Loops Embedded in a Hot Coronal Fan-Like Structure", ESLAB-97 (1998). Simnett, G. M., and Hudson, H. S.: "The Evolution of the Coronal Mass Ejection on February 23, 1997", ESLAB-97 (1998). Page 16 ------------------------------------------------------------------------------- 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 December 1997 November 1997 |------------------------------- | 6. PERFORMING ORG | CODE: O/H1-12 -----------------------------------------------|------------------------------- 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 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 November 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 | 16 | ------------------------|------------------------|-----------------|----------- For sale by: Superintendent of Documents, U.S. Government Printing Office