28 August 1995 M. Weber SXT CHIEF OBSERVER REPORT AND TABLE PLAN SXT TABLE PLAN FOR WEEK 35 (28-AUG-95 to 03-SEP-95) This will be a busy week for coordinated observing campaigns, as described in more detail below. Briefly stated, SXT may attempt further polar ray observations, continue with Hawaii in filament busting, and at the end of the week coordinate with the much heralded SPARTAN launch. The observing objectives of this TENTATIVE plan are: - Dark calibration on Monday. - Offpoint observing and terminators to a.) characterize stray light development b.) prepare for possible SPARTAN observations. - Standard observing and/or filament watching. - Coordinated observing with SPARTAN at the end of the week. The SXT Table Plan for the week is as follows: KSC Time (start) in JST Pass Table ID Comments _____________(= UT + 9 hrs)______#_______________________________ Monday 28-Aug-95 16:22 3 950828 P3 ARS1 DARKCAL Tuesday 29-Aug-95 13:14 2 950829 P2 ARS1 STD+LONG Wednesday 30-Aug-95 13:34 2 950830 P2 ARS1 OFF-PNTS " " 17:00 4 950830b P4 ARS1 STD+LONG Thursday 31-Aug-95 13:53 3 950831 P3 ARS0 FILAMENT Friday 01-Sep-95 14:12 3 950901 P3 ARS0 SPARTAN Saturday 02-Sep-95 ********* To Be Determined ********* Terminator-Offpointing: With the recent developments in the stray light perturbations, the terminator-offpoint program has entered a new phase. It will no longer be possible to calibrate for data before August 16th. Now a new offpoint program shall commence for data after August 16th. The SXT Team hopes to begin immediately in pre- paration for SPARTAN. Instructions for the tohbans will remain the same. The SSOC tohbans are required to manually insert the off-point OGs for the terminators in the OP tables. SSOC TOHBAN, please fax the preliminary OP list to D-tou when it contains a terminator so that the Chief Observer can suggest which OG's to be used. Dumping Patrol images: We request that KSC tohban continue to dump a patrol image each time an SXT table is loaded to facilitate the study of optimizing ARS parameters for an awfully quiet period. /// KSC and SSOC TOHBAN PLEASE NOTE: \\\ \\\ THIS TABLE PLAN IS SUBJECT TO CHANGE. /// The SXT Chief Observer sees three possibilities in particular this week. - The FILAMENT tables and STD+LONG tables may be re-arranged depending upon observing conditions and/or new information from our collaborators in Hawaii. This means that an SXT Table ID may change within a day of the upload. HOWEVER, the SXT Chief Observer shall try to give the tohban EXTRA WARNING if the PASS # is to be changed. - There is a possibility that an SXT Table will be composed to look at the polar faculae, in conjunction with the proposal of Koutchmy-san and Hara-san. The SXT CO will try to give the tohban ADVANCE WARNING if the upload schedule is to be changed. - As of this report, the SXT Team has not determined yet what the observing objectives will be in conjunction with SPARTAN. TOHBANS: THERE WILL ALMOST CERTAINLY BE AN SXT TABLE UPLOAD ON SATURDAY. You will be notified as to the schedule as soon as it has been determined. ____________________________________________________________________ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ SXT CHIEF OBSERVER'S REPORT for Week 34: 21-AUG-95 to 27-AUG-95 It has been a hectic week for the SXT Team. The Sun has shown an increase in activity, due to several factors. A first attempt was made to observe the solar north pole to see if polar rays can be detected at their base. It was discovered that the SXT "straylight" issue has recently changed in an abrupt and significant manner. Last, but never least, the ping-pong table was rediscovered and uncovered. SOLAR ACTIVITY The Sun has mustered its resources to achieve an X-ray level of months past. AR 7901 has increased its area considerably. AR 7902 has managed to produce at least one C-class event. And AR 7903, just arrived over the east limb, has also contributed to X-ray emissions. GOES data shows an obvious rise in radiation over a period of about a day. It is difficult to say if this is mostly due to de-occultation of AR 7903. SXT INSTRUMENT STATUS One of SXT's calibration issues has changed in a significant but recoverable manner. On November 13, 1992, a hole was made in the SXT aperture filter, permitting straylight to penetrate to the CCD. Calibration techniques were developed to compensate for the effect of this on SXT images. On August 16, 1995, the straylight increased by (roughly) a factor of two, probably due to a further failure of the entrance filter. The straylight level has been stable since then, and is "still well within the range of correction". The project of adjusting the calibration process is well under way. In all other respects, the SXT has been functioning properly. CURRENT AND UPCOMING CAMPAIGNS - SPARTAN Spartan 201-03 launch has been scheduled for August 31. The satellite will be deployed "on September 1 at 11:40 EDT to begin almost 45 hours of observations." As of August 26, the SXT Team is still considering its observing plan. The fact that Spartan will be operating over a weekend introduces some complications in our scheduling. - POLAR RAY CAMPAIGN On 25-Aug-95, SXT took PFIs of the solar north pole and low corona. This was mainly to provide a test run for SXT, and to provide some preliminary data for Koutchmy-san and Hara-san so that they may further formulate their requests for SXT observations. It is possible that another short observing period may be fixed for this week. - FILAMENT OBSERVATIONS SXT has been assisting Hawaii with filament observations, but there has of late been a lack of obvious targets. Regular communications between ISAS and Mees have been maintained. SCIENCE George Roumeliotis (Stanford U.) visited and gave a seminar on image reconstruction for SXT. By using new tools for this purpose, he has found a rather clear example of what appears to be a loop-loop interaction. Alas for our preconceptions about this, the point of reconnection seems to be dark, rather than bright. This is consistent with the difficult time we have had in general to prove the existence of macroscopic reconnection via the SXT data, and offers a clear challenge to others to work on the difficult questions of image interpretation (including resolution enhancement) in quantitative ways. This visit was timely, because Y. Hanaoka was one of the SSOC tohbans this week. He has now written a second paper on SXT data analysis for loop-loop interactions. This made the traditional farewell sushi lunch all the more interesting! PERSONNEL - In a truly heroic fashion, befitting a solar physicist, Hugh Hudson survived a four-day trip from Goddard to Japan, even coming to ISAS directly from Narita. Definitely indefatigable. - Kevin Reardon, arrival Thursday the 24th, is visiting from the University of Hawaii for three weeks. Among other things, he plans to work on prominence eruptions. SEMINARS - The seminar this week was given by George Roumeliotis of Stanford University. The title was "IRIS: An Algorithm for the Reconstruction of SXT Images." The visual examples were impressive.