Page 1 PROGRESS REPORT THE SOLAR-A SOFT X-RAY TELESCOPE (SXT) PROGRAM (CONTRACT NAS8-40801) (for June 1998) 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 amendment that contractually covers SXT Operations has finally been approved by all parties. We continue to strengthen the scientific team with new additions at LMPRL and through the Co-I institutions. << Solar Activity >> For the first half of June, the GOES level remained at mid-B level, trending upwards towards the end of the interval. There were about two dozen C flares, and two M flares. These included one beautiful over-the-limb M event - an example of a spiky post-flare loop system, of the sort seen occasionally with a side-on view. The largest sunspot group was AR 8232, with a peak sunspot area of 360 millionths. The other M event was extremely impulsive. During the latter half of June, the GOES level remained between B and C, with many C flares and two M flares. Active region 8253 was most active, thought it had a relatively small sunspot area of about 200 millionths at the end of the reporting period. << Campaigns >> During week 23, SXT took part in SOHO and TRACE observations of AR 8227, with Karin Muglach of ESA leading the SOHO effort. This was the region TRACE dedicated a two-week session towards, and the resulting data set could best be described as "unprecedented". We immediately started thinking about making this data set the focus of the CDAW this fall. During week 24, a Hida Observatory campaign (Kurokawa) focused on flux emergence and jets (Shimojo). This campaign has been less successful, partly because the cloud cover at Hida. Nevertheless we have one excellent Page 2 set of PFI-dominant data, filled with interesting phenomena, so it may be that the campaign has been a success in spite of the monsoon. At the end of June, we were watching AR 8253 as a part of JOP 83 and TRACE coordination. << Science >> Nitta started looking at data of the rising phase of a few flares in which the correspondence of the SXT and HXT L-band images is poor. An interesting thing is that the HXT L-band source, apparently located higher than the SXT loop, does not accompany a high-temperature area as revealed by SXT. But the higher energy channels of HXT show emission to be closer to the SXT source. Therefore, the HXT L-band source may represent nonthermal emission with a soft spectrum. A beautiful sigmoid active region (NOAA 8232) did it all this month, and we have learned something from it. The SXT chief observer noted the pre-event feature and sent an e-mail alert; in the meanwhile Alan McAllister noted the solar magnetic configuration and made an actual prediction. The new thing we may have learned is that any restructuring involved in the CME formation can repair itself fairly quickly. The "sigmoidicity" may have changed, but we don't really have any quantitative way yet to interpret the degree to which a solar structure looks S-shaped. The flare served to inflate the sigmoid, and the slow GOES event that followed the flare represented the formation of the post-flare loop system. There was an increase in Kp at the time predicted by Brueckner's law, pi days from Sun to Earth, within about 8% in this case. This is just one example of the strong result on halo CME effects pointed out by Chris St. Cyr at the SPD/AGU meeting last month. After the coronal mass ejection of 11-Jun-98, it was noted that the region was still "sigmoidal", though it didn't describe such a perfect S-shape. Since it seems that sigmoidal active regions are more likely to spawn coronal mass ejections, this might have been interpreted as meaning the region was still capable of eruption, even after 11-jun-98. The region did in fact erupt again, after rotating behind the southwest limb of the Sun. On 16-jun-98, the region spawned a beautiful CME that was captured in images by SXT and LASCO. The event registered as an M-class flare (see the GOES plot above). << 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 May were 62586 accesses and 2639 Mbytes transferred. << Yohkoh Operations and Health >> Yohkoh and the SXT continue to function very well. Page 3 SXT experienced a normal level of Single Event Upset (SEU) events during the month: * NO SEU's THIS MONTH * Page 4 << Data Flow >> Month Full Frame Images Observing Region Images Received Lost Received Lost Loss % QT FL Tot Thru Mar-96 364894 157657 1505906 362679 1868585 751182 28.59 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 7671 1557 25649 1396 27045 8045 22.93 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 6691 1376 26297 15306 41603 7131 14.63 Dec-97 6806 1013 28472 2136 30608 5263 14.67 Jan-98 5715 1803 23479 3232 26711 9918 27.08 Feb-98 6606 1644 25257 3606 28863 8989 23.75 Mar-98 6043 2056 23029 10399 33428 10939 24.66 Apr-98 6537 1103 22656 8087 30743 6339 17.09 May-98 7569 1838 28292 19018 47310 9868 17.26 Jun-98 4067 1091 16083 3987 20070 6080 23.25 Jul-98 0 0 0 0 0 0 NaNQ Total 549912 207402 2219379 475729 2695108 996472 26.99 Number of Full Frame Images Received: 549912 Number of Observing Region Images Received: 2695108 Total: 3245020 Approximate Number of Shutter Moves/CCD Readouts: 5642140 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 (%) 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 53.71 869.8 182715 14910 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 55.17 924.8 202153 18993 22.5 / 2 23.1 N/A Dec-97 55.51 937.6 206194 20219 21.9 N/A Jan-98 56.06 958.0 212189 22121 23.9 N/A Feb-98 55.94 953.7 209254 22122 23.8 / 2 22.6 N/A Mar-98 56.29 966.6 213519 23249 21.8 N/A Apr-98 56.44 972.1 214676 23890 20.8 N/A May-98 56.90 989.4 215651 26905 21.4 N/A Jun-98 56.95 991.4 215192 27223 19.8 N/A Jul-98 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-JUN-98 and 30-JUN-98 HUDSON 1-JUN-98 * 20-JUN-98 20 28-JUN-98 30-JUN-98 * 3 (total of 23 days) MCKENZIE 1-JUN-98 * 29-JUN-98 29 (total of 29 days) ---------------------------------------------------------------- Grand Total of 52 days for 2 people NOTE: The "*" signifies travel that actually ends after 30-JUN-98 SXT Foreign Travel between 1-JUL-98 and 31-JUL-98 HUDSON 1-JUL-98 * 12-JUL-98 12 18-JUL-98 25-JUL-98 8 (total of 20 days) NITTA 28-JUL-98 31-JUL-98 * 4 (total of 4 days) SHING 5-JUL-98 11-JUL-98 7 (total of 7 days) SHIRTS 1-JUL-98 31-JUL-98 31 (total of 31 days) SLATER 1-JUL-98 26-JUL-98 26 31-JUL-98 31-JUL-98 * 1 (total of 27 days) ---------------------------------------------------------------- Grand Total of 89 days for 5 people NOTE: The "*" signifies travel that actually ends after 31-JUL-98 Respectfully submitted, Thomas R. Metcalf Frank Friedlaender Page 7 ------------------------------------------------------------------------------- NASA REPORT DOCUMENTATION PAGE (IN LIEU OF NASA FORM 1626) --------------------|--------------------------|------------------------------- 1. REPORT NO. | 2. GOVERNMENT | 3. RECIPIENT'S DR-01 | ACCESSION NO. | CATALOG NO. --------------------|--------------------------|------------------------------- 4. TITLE AND SUBTITLE | 5. REPORT DATE Monthly progress report - for the month of | 10 July 1998 June 1998 |------------------------------- | 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 Martin Missiles and Space |------------------------------- Advanced Technology Center, O/H1-12, B/252 |11. CONTRACT OR GRANT NO. 3251 Hanover Street, Palo Alto Ca. 94304 | NAS8 - 40801 -----------------------------------------------|------------------------------- 12. SPONSORING AGENCY NAME AND ADDRESS |13. TYPE OF REPORT AND Marshall Space Flight Center (Explorer Program)| PERIOD COVERED Huntsville Alabama 35812 | Progress report for the month Contact: John Owens | of June 1998 |------------------------------- |14. SPONSORING AGENCY | CODE MSFC / AP32 -----------------------------------------------|------------------------------- 15. SUPPLEMENTARY NOTES ------------------------------------------------------------------------------- 16. ABSTRACT The SOLAR-A Mission is a program of the Institute of Space and Astronautical Science (ISAS), the Japanese agency for scientific space activity. The SOLAR-A satellite was launched on August 30, 1991, to study high energy phenomena in solar flares. As an international cooperative agreement, Lockheed, under NASA contract, is providing a scientific investigation and has prepared the Soft X-ray Telescope (SXT), one of the two primary experiments of the mission. --------------------------------------|---------------------------------------- 17. KEY WORDS (SUGGESTED BY | 18. DISTRIBUTION STATEMENT AUTHOR(S)) Solar-A, X-ray, CCD, | Space Science, Solar Physics ------------------------|-------------|----------|-----------------|----------- 19. SECURITY CLASSIF. | 20. SECURITY CLASSIF. | 21. NO OF PAGES |22. PRICE (OF THIS REPORT) | (OF THIS PAGE) | | None | None | 7 | ------------------------|------------------------|-----------------|----------- For sale by: Superintendent of Documents, U.S. Government Printing Office