Page 1 PROGRESS REPORT THE SOLAR-A SOFT X-RAY TELESCOPE (SXT) PROGRAM (CONTRACT NAS8-00119) (for October 2000) 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 Activities for this month were nominal. Computer upgrades are being implemented for more efficient operations and data archiving.They will be sent to Japan as soon as all the proper paperwork has been prepared. SOLAR ACTIVITY At the beginning of October, the west limb of the sun produced several M-class and one X1.2 flares. As these regions faded over the limb, activity decreased and baseline GOES level fell to B7. In mid-October, Solar activity was generally low, except for active region 9182 which produced an M1.5 flare on 12 Oct UT, and an M1.1 on 14 Oct, both near the northwest limb. 9182 also produced an M-class flare on 16 Oct UT, behind the west limb (M2.5). Another occurred on the disk on October 21 in NOAA 9201 (M3.0). At the end of October, Solar activity was gradually rising as the GOES background level and the frequency of sub-M class flares were both increasing. GOES observed 3 M-class flares: M1.1 on 27th, M1.7 on 28th, and M4.4 on 29th. SXT saw the former 2 and a C8.5 flare on 26th. The M4.4 LDE event was eruptive. Page 2 CAMPAIGNS SXT continued to support JOP 104 throughout October though because of (1) more activity elsewhere and (2) pointing difficulties, we were a non-participant for much of this period. SXT supported B. Schmeider's Flare campaign through October 15. SCIENCE Coronal holes are large-scale coronal features where plasma density is extremely low, and thus they look like a hole or a void in the corona. They often appear in polar regions and are thought to be areas where the magnetic field is open to space. They are also known as the base of high-speed coronal wind. The first continuous observations of these structures were made with Skylab in the 1970s in soft X-rays. Coronal holes sometimes take the shape of channels rather than round holes, and may hold their shape though several rotation of the sun. A famous coronal hole observed with Skylab in 1973 is well known by the nickname of "The Boot of Italy" after its elongated shape. An interesting fact is that coronal holes seem to rotate like rigid bodies, while sunspots are known to rotate faster in the equatorial zone and slower in higher latitude zones. This raises questions about how the relationships of coronal holes and the neighboring sunspots change through the rotations. Do the sunspots push across channels? Takeda and McKenzie report that, in the last several weeks, Yohkoh observed a coronal hole which is very similar to one in 1973. We can trace the evolution of this feature through at least two rotations of the Sun. The "channel" returned to the same place in 27 days without largely changing its straight shape. This suggests that the coronal hole rotated like a rigid body at the corresponding period. On the other hand, the active regions located on each side of the channel, proceeded faster than the channel, and slightly distorted its shape. (In the present case, they made the channel more straight and stylish, though!) This remarkable coronal hole seemed to extend from pole to pole. This is a bit of a puzzle: How can it be a continuous feature, since the north and south poles must have different magnetic polarities? To see this more closely, we consult with the magnetic fields and find from the MDI images that the coronal hole in question has primarily negative polarity, the same polarity as the current north pole. The polarity appears to be uniform through its whole stretch, even in the part near the south pole. With a stretch of imagination, we might say that we caught the negative polarity just invading the south pole. Canfield continued to work with Jibben on the comparison of SXT jet / MCCD surge events to maps of twist in photospheric magnetic fields, inferred from Mees vector magnetograms. Jibben finished this comparison and discovered a statistically compelling relationship between the direction of spin of surges and the handedness of twist in magnetic Page 3 fields at their apparent point of origin. Canfield also worked with Colman on a paper on moving blue-shift events in the Mees data, based on Wuelser's list of the best observed Mees/Yohkoh flares. Colman found a significant relationship between the frequency of preflare moving blue-shift events and the eruptive nature of the flares Nitta did some calculation of SXT Be/thick Al temperatures from power-law spectra. He found that a very flat photon spectrum (gamma = -1.4) amounts to only 21 MK. If one has a power-law spectrum of gamma = -3.0 down to 1 keV, the SXT temperature is only 7 MK. He is using this argument to to argue against the HXT L/M1 loop-top sources being due to trapped non-thermal electrons. PUBLICATIONS Submitted: "Active region Transient Brightenings. A simultaneous view by SXT, EIT and TRACE", D. Berghmans, D. McKenzie and F. Clette, Astronomy & Astrophysics. Accepted: Closure on Mesospheric/Thermospheric Nitric Oxide Abundance P. K. Swaminathan, D. F. Strobel, L. Acton and L. J. Paxton Journal: Physics and Chemistry of the Earth, in press. "Supra-arcade Downflows in Long-duration Solar Flare Events", by McKenzie & Hudson, was accepted for publication in the book "Magnetic Reconnection in Space and Laboratory Plasmas", which is a special issue of the journal "Earth, Planets and Space (EPS)". Published: "The Relation between Hot and Cool Loops", N. Nitta, 2000, Sol. Phys. 195, 123 "Coronal Dimmings and Energetic CMEs in April-May 1998", B. J. Thompson, E. W. Cliver, N. Nitta, C. Delannee, J.-P. Delaboudiniere, 2000, GRL, 27, 1431 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 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 October were 140307 accesses and 7853 Mbytes transferred for the SXT website and 275219 accesses and 5545 Mbytes transferred for the YPOP website. Page 4 Solar Week 2000 ran from October 9-13 and was very successful. Ten female scientists from the US and the UK participated in the online Question and Answer sessions to great effect. We had 65 teachers participating in Solar Week from 20 states, bringing with them some 3500-4000 students. We averaged over 100 questions per day. Solar Week will run again in Spring 2001. The URL for Solar Week is http://www.lmsal.com/YPOP/solarweek/ YOHKOH OPERATIONS AND HEALTH Yohkoh and the SXT continue to function very well. Yohkoh lost Canopus lock and was rotating rather rapidly around the Z-axis on October 9. The problem apparently began at the beginning of operations, and the angle reached about 30 degrees (negative PA) at 03:09 UT on 9-Oct before it was arrested. Canopus was reacquired by October 12. The causes of this anomaly are still being investigated. SXT experienced a normal level of Single Event Upset (SEU) events during the month: Bit Map Error 08-Oct-00 Pass 1: 001008-1548 Recovered in the same pass Bit Map Error 16-Oct-00 Pass 3: 001016-0101 Recovered in the same pass Bit Map Error 17-Oct-00 Pass 1: 001017-1340 Recovered in the same pass Bit Map Error 20-Oct-00 Pass 1: 001020-0102 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 Aug-98 564941 211801 2278310 498843 2777153 1020580 26.62 Sep-98 6776 1432 21814 11626 33440 7753 18.82 Oct-98 6573 1901 23520 5198 28718 9220 24.30 Nov-98 6442 1695 25124 26948 52072 9920 16.00 Dec-98 5962 2005 21490 15770 37260 10561 22.08 Jan-99 5494 1825 20087 17620 37707 9622 20.33 Feb-99 5729 1525 30802 9798 40600 10630 20.75 Mar-99 6807 1844 24721 12354 37075 10064 21.35 Apr-99 6715 1371 25113 4179 29292 7791 21.01 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 3835 1166 11012 1501 12513 4563 26.72 Total 726097 260159 2863329 820586 3683915 1268100 25.61 Number of Full Frame Images Received: 726097 Number of Observing Region Images Received: 3683915 Total: 4410012 Approximate Number of Shutter Moves/CCD Readouts: 7495037 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 (%) Sep-98 57.43 1009.5 218520 29683 20.9 N/A Oct-98 57.59 1015.3 220504 30221 21.3 N/A Nov-98 58.17 1037.0 223755 34614 22.5 / 2 23.4 N/A Dec-98 57.86 1025.5 221918 32420 23.8 N/A Jan-99 58.74 1058.6 227503 38238 23.1 N/A Feb-99 58.44 1047.4 224002 36198 23.2 N/A Mar-99 59.26 1078.1 227900 43051 21.7 N/A Apr-99 58.82 1061.4 225973 38963 23.8 / 1 21.4 N/A 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 61.48 1161.0 236842 62565 22.1 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-OCT-00 and 31-OCT-00 HANDY 1-OCT-00 * 01-OCT-00 1 07-OCT-00 14-OCT-00 8 (total of 9 days) HUDSON 1-OCT-00 * 1-OCT-00 1 4-OCT-00 13-OCT-00 10 (total of 11 days) MCKENZIE 13-OCT-00 31-OCT-00 * 19 (total of 19 days) NITTA 1-OCT-00 * 1-OCT-00 1 (total of 1 days) TAKEDA 1-OCT-00 * 4-OCT-00 4 7-OCT-00 31-OCT-00 * 25 (total of 29 days) ---------------------------------------------------------------- Grand Total of 69 days for 5 people NOTE: The "*" signifies travel that actually ends after 31-OCT-00 SXT Foreign Travel between 1-NOV-00 and 30-NOV-00 HUDSON 15-NOV-00 30-NOV-00 * 16 (total of 16 days) MCKENZIE 1-NOV-00 * 15-NOV-00 15 (total of 15 days) TAKEDA 1-NOV-00 * 10-NOV-00 10 18-NOV-00 30-NOV-00 * 13 (total of 23 days) ---------------------------------------------------------------- Grand Total of 54 days for 3 people NOTE: The "*" signifies travel that actually ends after 30-NOV-00 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 November 2000 October 2000 |------------------------------- | 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 October 2000 |------------------------------- |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 | ------------------------|------------------------|-----------------|-----------