RHESSI Tohban report, 20-June-2005 to 27-June-2005 Hugh Hudson 1. Overview: This week saw the return from pulsar offpointing. We did not miss much solar data of interest, except for one M-class limb event 16-Jun. Return to the Sun commenced at about 13:16 24-Jun and was complete at TBD. Mark says "I returned the ACS to normal mode at 176-16:24:14 UTC. The spacecraft had already been on the Sun for 4-5 orbits, but was still in precession mode. Not sure how much that will have affected the pointing accuracy, except to note that precession mode does not have the calibration factor built in, to compensate for the difference between FSS-SAS alignment." 2. Solar Activity Extremely low, but we were offpointed anyway. The flare list looks odd - the RHESSI flare flag can't seem to cope with an 8-degree offpoint: +++++ How many GOES flares occurred? Flares above B, C, M, X class were 30 4 0 0 RHESSI flare list contains 0 over the time range 19-Jun-05 26-Jun-05 No overlapping RHESSI flares to count, sorry ++++++ There are hints (helioseismic and backside halo CME) that something is approaching the E limb now. A few C-class flares are coming from a new AR just this side of the NE limb. 3. Memory Management We had severe SSR problems at the end of the offpoint exercise, to the extent that we maxed out on the last day. Accordingly the interval between the entry into precession mode (return to Sun), about 13:16 24-Jun and the final Berkeley pass, about 00:53 25-Jun was zeroed out of telemetry by moving the write pointer back. The decimation was re-set and memory fill descended below 50% during the passes on 26-Jun. There is a clear loss of low-energy counts, probably due to automatic decimation, from about 08:00 24-jun (prior to the return). Pulsar analyzers beware. The SSR problem presumably came from a combination of un-decimation and particularly intense particle fluxes. 4. Data Gaps From write-pointer setting, 13:16 24-Jun to 00:53 25-Jun The daily average plots have not been updating since 13-Jun. The SOH plots are two days behind (6/24 available at time of writing). 5. Pulsar Sa"m and your tohban had great fun looking at pulsar data on Friday. It is quite clear in the spectrograms even when the Sun was visible, because normally the solar counts are below 10 keV (soft spectrum) and the pulsar counts above 10 keV (hard spectrum). The pulsations are obvious in simple power spectra and have a period of about 102.5 s, somewhat shorter than the earlier values (~104 s) reported for this object (which has 31 names, most humbly possibly BD+26 883 or maybe HD 245770). 6. Other Need to spin up. 7. Next week's Tohban: Abby Goodhue