SXT Status Report 2 - 24 Apr. 1995 (Weeks 14-16) --------- James R. Lemen 24-Apr-95 This report covers three weeks. I arrived in Japan at beginning of April and immediately came down with the flu. I am slowly catching up in all the necessary areas. At the beginning of the time covered by this report the cherry blossoms reached their peak in the region around Sagamihara. SOLAR ACTIVITY During week 14 the Sun became very quiet with the GOES flux riding along at the A level. There was a large polar crown filament in the southern hemisphere. We attempted a filament watch campaign to try to observe the filament with higher time and spatial resolutions in case the filament erupted. During week 15 AR 7863 began to grow and produced several C-class flares. Towards the end of week 16 this region produced more C-class flares and three M-class flares as the region reached the west limb. This region will rotate over the limb in the beginning of week 17 and at that time there will be no significant active regions present on the solar disk. COORDINATED CAMPAIGNS N. Gopalswamy (University of Maryland) observed at the VLA on 12, 15, 16 April. His observing target was AR 7863, which was also the Yohkoh and Mees targets. On 18-Apr-95 at about 18:00 UT was the launch of HRTS-IX. The HRTS instrument was pointed to AR 7863. The SXT was operated in ARS2 pointing mode to insure that it was also observing the same target as HRTS. Not all the data has been received and reformatted at the time of this report. Finally, there was an attempt to perform an X-ray Bright-Point Campaign during 19-21 April and 23-26 April. The organizer of this campaign is Karen Harvey and it involved Kitt Peak, Sac Peak, Big Bear and the Mees observatories. The campaign was not conducted, however, because it was judged that the solar activity was too high for SXT operational safety. We might be able to conduct one day of operations in the coming week. The campaign will be rescheduled for mid-June 1995. SXT CALIBRATION The program to acquire off-point terminator images continues. For various reasons (mostly SSOC operation errors) we have not had much success in the past few weeks, but we are slowly filling in a grid of required pointings. SXT INSTRUMENT STATUS SXT continues to function smoothly and without problems. There was a bit map error on 20-Apr-95. The error flag was reset on 21-Apr-95 and this had no effect on operations or SXT observations. Sam Freeland and Hirohisa Hara developed a new SXT recovery plan that was tested during week 15. This plan makes sure that the SXT Halt operation is included as a part of the recovery. This will allow the continued planning of terminator operations during KSC contacts. In addition, the new recovery plan has been made more efficient and should enable quicker recoveries of the instrument. The new NASA-contract-purchased computers, which were installed at ISAS last month by Gary Linford and Lawrence Shing, are fully functional and they have made the life of the SXT Chief Observer much more pleasant. The reformatter, which used to take three to four days on the old file server, now runs in about 12 hours on the new isass0. Sam Freeland has completed the installation of the various cron jobs. The reformatting is task is completely caught up at present. YOHKOH PASS CONFLICTS We lost the following passes at KSC due to conflicts with the Japanese ASCA and SFU missions: Week 14: 11 KSC contacts Week 15: 7 KSC contacts Week 16: 7 KSC contacts The operations of the IRTS instrument (the Infrared instrument) on SFU were extended until 26-Apr-95. We hope that after this time that there will be fewer conflicts with the SFU satellite, but this has not been confirmed at this time. SEMINARS On 6 April 1995 there were two interesting seminars. The first was by T. Sakurai (NAOJ) entitled "Maximum Energy of Force-Free Magnetic Fields" and the second was by T. Sakao (NAOJ) entitled "Characteristics of Hard X-ray Footpoint Sources in Solar flares." On 12 April 1995 the seminar speakers were K. Hori (Tohoku Univ/NAOJ) entitled "Pseudo Two-Dimensional Hydrodynamic Modeling of Flare Loops" and M. Shimojo (Tokai University), "Statistical Study of X-ray Jets." PERSONNEL Keith Strong and Mark Weber returned to the States at the end of Week 14. James Lemen arrived to replace them but was not very effective for a few days while suffering from he flu. Fortunately, Hugh Hudson filled in as Chief Observer for part of Week 14. Jean-Pierre Wuelser arrived during week 14 to begin a three week visit. During week 16 Hudson traveled to California to attend the radio telescope seminar. Sam Freeland departed for California towards the end of week 16. Fortunately for Sam, he traveled through Yokohama on Thursday, missing the gas attacks that occurred there on Wednesday (in the train station) and Friday (in a department store -- no deaths from either attack but many taken to hospital). Week 14: Tohbans: SSOC: S. Masuda, H. Watanabe KSC: S. Yasuno, M. Takahashi SXT Chief Observer: H. Hudson SXT Systems and Data Engineer: S. Freeland Week 15: Tohbans: SSOC: H. Koshiishi, J. Sato KSC: S. Yasuno, T. Sakao SXT Chief Observer: J. Lemen SXT Systems and Data Engineer: S. Freeland Week 16: Tohbans: SSOC: M. Nishio, M. Irie KSC: T. Sakao, T. Yokoyama SXT Chief Observer: J. Lemen SXT Systems and Data Engineer: S. Freeland