Page 1 PROGRESS REPORT THE SOLAR-A SOFT X-RAY TELESCOPE (SXT) PROGRAM (CONTRACT NAS8-00119) (for June 2001) 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 Martin, 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 Martin Solar and Astrophysics 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 There were no unusual programmatic matters this month. Final preparations for the Senior Review have now been completed. We are entering the last six months of the current contract phase. SOLAR ACTIVITY In early June, activity started out low with the the largest flare a C5.6 at 18:22UT on 3-June-01. But activity picked up with 4 GOES M-class flares and many C-class flares as the GOES background level increased from the B to C level. Solar Activity continued at a moderate level into mid-June with 3 GOES M-class flares and many C-class flares. The GOES background level was almost at the C level. Two regions in the eastern hemisphere were responsible for a great deal of the activity. Towards the end of June, solar activity was higher with 4 M-class and 1 X-class flare, mostly on June 23. The highlight was the solar eclipse on 21 June, in which SXT observed two partial eclipses. The new millennium's first totality was visible along Angola, Zambia, Zimbabwe, Mozambique and the island of Madagascar. As June came to a close, solar activity declined again to low levels. At the end of June, the solar disk sported a coronal hole that extended to low latitudes, as well as an active region at fairly high latitude (South 48). CAMPAIGNS We participated in MEDOC campaign #7, which involved multiple SOHO Page 2 JOPs. The first week was spent on filaments to study their dynamics, and the second week was to observe flares with a specific objective to study helium abundance. The Sun was not not necessarily cooperative, however. We tested a new, simpler flare mode table for support of HESSI. The table includes AlMg and Be images in full resolution, 1x1 ROI, and AEC set to allow no saturation. Starting DPEs were set to 5 & 6 (for AlMg) and 13 & 15 (for Be), because these levels are well matched to the ~C2 level of the flare trigger threshold. For the 21-Jun solar eclipse, we ran PFI-dominant for high-cadence partial-Sun images pointed at the "4th contact" point on the Sun's west limb. We got terrific (albeit noisy) images of the moon's stillstand and reversal. We also acquired some targeted two-filter PFIs in support of an eclipse campaign undertaken by Meisei University. At the time of limb passage, the lunar limb was only moving 0.3-0.4 arcsec/sec, so our sample interval of 2 sec gave us TRACE-like resolution for limb location. SCIENCE Alexander analyzed a nice CME event seen by SXT and was able to measure the acceleration of an erupting structure which attained a speed of over 750 km/s by the time it exited the SXT field-of-view. A constant acceleration fit to this data yielded a value of 1650 m/s^2. The 20s cadence of the SXT observations meant that a more detailed fit to the data could be performed and it was found that a fluxrope model of the type proposed by Terry Forbes could fit the data better than the constant acceleration approach. This result has been written up and submitted to GRL. Canfield participated in Working Group 1 of the SHINE meeting in Snowmass, which addressed two basic issues, one of which centered on observational evidence for reconnection prior to CMEs. He presented a paper he is writing with recent graduate Angela Colman on a set of 16 flares observed for at least two or three hours before the event. The work demonstrates that the H-alpha blue-shift-event signature of magnetic reconnection originally discovered by Canfield and Reardon in the famous November 15, 1991 Yohkoh flare is present for at least several hours before virtually all the eruptive flares in the dataset, but not before non-eruptive ones. Moreover, it demonstrates that the blue-shift events present before the eruptive flares cease after them. The obvious inference is that magnetic reconnection plays a role in establishing conditions that lead to eruptive flares, and hence CMEs. Metcalf analyzed the magnetic free energy in AR8299 and found that the free energy in this active region was significant with a magnitude of about 10^33 ergs, though the active region was not flare productive. This amount of free energy was more than enough to explain the enhanced heating of the active region corona. The free energy dipped to a value consistent with zero for one hour during the observation. SXT images revealed that, around the time of this dip in the free energy, the Page 3 coronal structure of AR~8299 and the nearby AR~8297 changed significantly. SXT observed the brightening of a cusp connecting AR~8299 and AR~8297 and observed coronal dimming in both active regions, suggesting that a gradual CME was launched as the magnetic energy dipped. Further, the magnetic connection between AR~8299 and AR~8297 was temporarily severed during the energy dip and the magnetic field took on a more open configuration afterwards. Unfortunately, LASCO data were not available to confirm the existence of a halo CME. However, the circumstantial evidence points to the magnetic free energy as the energy source for the postulated event. PUBLICATIONS Submitted: "CME acceleration in the low solar corona", Alexander, Metcalf and Nitta, submitted to GRL Aschwanden,M.J.2001 ApJL, "Revisiting the Determination of the Coronal Heating Function from Yohkoh Data" Accepted: Aschwanden,M.J. and Alexander,D.2001 Solar Physics, "Flare Plasma Cooling from 30 MK down to 1 MK modeled from Yohkoh, GOES, and TRACE observations during the Bastille-Day Event (2000 July 14)" Aschwanden,M.J.2001 The Astrophysical Journal, "An Evaluation of Coronal Heating Models for Active Regions based on Yohkoh, SoHO, and TRACE Observations" Yan,Y., Aschwanden,M.J., Wang,S.J, and Deng,Y.Y., "Evolution of Magnetic Flux Rope in NOAA 9077 Active Region on 14 July 2000" "Flare Plasma Cooling from 30 MK down to 1 MK modeled from Yohkoh, GOES, and TRACE observations during the Bastille-Day Event (2000 July 14)", Aschwanden & Alexander, ApJ, accepted Published: "Dictionary of Geophysics, Astrophysics and Astronomy" published, editor R. Matzner. "Chromospheric Heating in the Late Phase of Two-ribbon Flares", Czaykowska, Alexander and De Pontieu, ApJ, 552, 849, (2001) published 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 LMSAL SXT WWW homepage (http://www.lmsal.com/SXT/). We receive requests for Page 4 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 June were 108634 accesses and 6,561 Mbytes transferred for the SXT website and 144972 accesses and 3,667 Mbytes transferred for the YPOP website. YOHKOH OPERATIONS AND HEALTH Yohkoh and the SXT continue to function very well. SXT experienced a normal level of Single Event Upset (SEU) events during the month: SXT Bit Map Error 04-Jun-01 Pass 3: 010604-0516 Recovered in the same pass. SXT Bit Map Error 29-Jun-01 Pass 4: 010629-1444 Recovered in the same pass. Page 5 DATA FLOW Month Full Frame Images Observing Region Images Received Lost Received Lost Loss % QT FL Tot Thru Apr-99 615454 225384 2471021 602336 3073357 1096101 26.10 May-99 6459 1807 35467 12092 47559 13757 22.44 Jun-99 6217 1915 23542 13051 36593 10086 21.61 Jul-99 5591 1745 20409 25747 46156 9670 17.32 Aug-99 6827 2503 21725 23361 45086 11844 20.80 Sep-99 5768 2011 21890 3434 25324 10846 29.99 Oct-99 5768 2308 22994 10487 33481 11517 25.59 Nov-99 7552 3425 20754 18772 39526 11974 23.25 Dec-99 7488 2791 22047 5354 27401 10663 28.01 Jan-00 5426 1736 19802 4040 23842 8958 27.31 Feb-00 6533 2052 21801 7017 28818 8982 23.76 Mar-00 6447 2007 22692 21914 44606 11192 20.06 Apr-00 6412 2100 31195 7214 38409 13438 25.92 May-00 6995 1556 28175 14961 43136 8967 17.21 Jun-00 7043 1722 24413 16369 40782 8690 17.57 Jul-00 6674 1920 23505 31739 55244 10235 15.63 Aug-00 9623 1996 20925 1197 22122 6577 22.92 Sep-00 8835 2240 22233 5764 27997 8307 22.88 Oct-00 6348 1524 23309 6629 29938 7916 20.91 Nov-00 6525 1639 20087 10318 30405 6972 18.65 Dec-00 6585 1918 20718 5422 26140 8071 23.59 Jan-01 5610 1231 20469 3161 23630 7317 23.64 Feb-01 6917 1497 25366 1144 26510 7871 22.89 Mar-01 6851 1272 26315 17139 43454 9470 17.89 Apr-01 5531 1804 15991 20001 35992 9216 20.39 May-01 7410 1758 21042 1767 22809 7152 23.87 Jun-01 496 73 1464 59 1523 297 16.32 Total 783385 273934 3049351 890489 3939840 1336086 25.32 Number of Full Frame Images Received: 783385 Number of Observing Region Images Received: 3939840 Total: 4723225 Approximate Number of Shutter Moves/CCD Readouts: 8050009 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 6 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 (%) May-99 58.68 1056.4 225385 37726 21.6 N/A Jun-99 59.40 1083.0 230091 42440 22.0 N/A Jul-99 59.78 1097.5 231236 46337 23.8 / 1 20.6 N/A Aug-99 59.39 1083.0 229319 43067 21.7 N/A Sep-99 60.04 1107.3 231585 49084 21.8 N/A Oct-99 59.66 1092.9 229735 45263 22.8 N/A Nov-99 59.90 1102.0 231288 47102 23.0 N/A Dec-99 60.55 1126.3 233523 53920 22.5 / 2 25.3 N/A Jan-00 60.27 1115.9 233820 50214 23.4 N/A Feb-00 60.93 1140.6 235079 56836 23.8 N/A Mar-00 60.72 1132.8 234174 54661 22.9 N/A Apr-00 61.10 1147.0 235252 58348 22.2 N/A May-00 61.00 1143.1 234569 57445 21.2 N/A Jun-00 61.19 1150.3 235622 58946 22.8 N/A Jul-00 61.96 1179.3 238114 66905 19.3 N/A Aug-00 61.27 1153.4 236108 59965 56.9 / 2 21.7 N/A Sep-00 61.08 1146.2 235644 58449 22.1 N/A Oct-00 61.44 1159.5 237142 61667 23.1 N/A Nov-00 60.99 1142.7 235849 57271 24.2 N/A Dec-00 61.59 1165.2 237454 63656 23.8 / 2 21.8 N/A Jan-01 61.64 1167.3 238962 62922 22.2 N/A Feb-01 61.84 1174.6 239218 65324 23.5 N/A Mar-01 61.89 1176.7 239128 65898 23.1 N/A Apr-01 61.92 1177.5 239784 66169 22.6 N/A May-01 62.25 1189.9 240631 69412 22.8 N/A Jun-01 N/A N/A N/A N/A 21.9 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 7 PERSONNEL TRAVEL SXT Foreign Travel between 1-JUN-01 and 30-JUN-01 BARTUS 1-JUN-01 * 27-JUN-01 27 (total of 27 days) HUDSON 14-JUN-01 24-JUN-01 11 (total of 11 days) MCKENZIE 6-JUN-01 30-JUN-01 * 25 (total of 25 days) TAKEDA 5-JUN-01 30-JUN-01 * 26 (total of 26 days) ---------------------------------------------------------------- Grand Total of 89 days for 4 people NOTE: The "*" signifies travel that actually ends after 30-JUN-01 SXT Foreign Travel between 1-JUL-01 and 31-JUL-01 BARTUS 17-JUL-01 31-JUL-01 * 15 (total of 15 days) HUDSON 20-JUL-01 30-JUL-01 11 (total of 11 days) MCKENZIE 1-JUL-01 * 10-JUL-01 10 (total of 10 days) TAKEDA 1-JUL-01 * 31-JUL-01 * 31 (total of 31 days) ---------------------------------------------------------------- Grand Total of 67 days for 4 people NOTE: The "*" signifies travel that actually ends after 31-JUL-01 Respectfully submitted, Thomas R. Metcalf Frank Friedlaender Page 8 ------------------------------------------------------------------------------- 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 2001 June 2001 |------------------------------- | 6. PERFORMING ORG | CODE: O/L9-41 -----------------------------------------------|------------------------------- 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/L9-41, B/252 |11. CONTRACT OR GRANT NO. 3251 Hanover Street, Palo Alto Ca. 94304 | NAS8 - 00119 -----------------------------------------------|------------------------------- 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: Larry Hill | of June 2001 |------------------------------- |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 | 8 | ------------------------|------------------------|-----------------|-----------