Hubble Space Telescope Daily Report #2680 08/07/00
HUBBLE SPACE TELESCOPE
DAILY REPORT #2680
PERIOD COVERED: 0000Z (UTC) 08/04/00 – 0000Z (UTC) 08/07/00
Daily Status Report as of 220/0000Z
1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:
1.1 Completed Five Sets of WF/PC-2 8826 (Cycle 9 Supplemental Darks pt 1)
The WF/PC-2 was used to perform a T dark calibration program that obtains three dark frames every day in order to provide data for monitoring and characterizing the evolution of hot pixels. There were no reported anomalies.
1.2 Completed Two Sets of STIS/CCD 8439 (Bias Monitor-Part 2 C8)
The Space Telescope Imaging Spectrograph (CCD) was used to monitor the bias in the 1×1, 1×2, 2×1, and 2×2 bin settings at gain=1, and 1×1 at gain = 4, to build up high-S/N superbiases and track the evolution of hot columns. The proposal completed with no reported problems.
1.3 Completed STIS/CCD/MA2 8266 (Coherence Length of Lyman-Alpha Absorbers at z ~ 1)
The Space Telescope Imaging Spectrograph (CCD and MA2) was used to measure the coherence length of Lyman-Alpha absorbers in the redshift range 0.5 < z < 1.1, using a new pair of quasars with a separation of 130 arcseconds. For quasars with this brightness {R = 18.1}, redshift and separation are very rare. Coincident absorbers along the line-of-sight to quasar pairs can reveal the geometry of the diffuse but highly ionized gas that makes up the Lyman-Alpha forest; this gas represents the majority of the baryons and it traces the underlying dark matter distribution. The observations completed with no reported anomalies.
1.4 Completed Seven Sets of WF/PC-2 8805 (POMS Test Proposal: WFII Parallel Archive Proposal Continuation)
The WF/PC-2 was used to perform a generic target version of the WFPC2 Archival Pure Parallel program. The program will be used to take parallel images of random areas of the sky, following the recommendations of the Parallels Working. The proposal completed with no reported problems.
1.5 Completed WF/PC-2 8445 (WF/PC-2 Cycle 8 Earth Flats)
The WF/PC-2 was used to make Cycle 8 Earth flat calibration observations. This is to obtain sequences of earth streak flats to construct high quality flat fields for the WF/PC-2 filter set. The observations were executed as scheduled, and no anomalies were noted.
1.6 Completed Two Sets of STIS/MA1 8426 (Cycle 8 MAMA Dark Measurements)
The Space Telescope Imaging Spectrograph (MA1) was used to make a routine Cycle-8 MAMA dark noise calibration measurement. This proposal will provide the primary means of checking on the health of the MAMA detectors. This is done through frequent monitoring of the background count rate. The observations were completed as planned, and no problems were reported.
1.7 Completed STIS/CCD/MA1 8662 (A Snapshot Survey of the Hot Interstellar Medium)
The Space Telescope Imaging Spectrograph (CCD And MA1) was used to obtain snapshot STIS echelle observations of key tracers of hot interstellar gas {C IV, N IV, and Si IV} for selected FUSE Team O VI survey targets with known UV fluxes. By taking advantage of the snapshot observing mode we will efficiently obtain a large number of spectra suitable for the study of the highly ionized hot component of the interstellar medium {ISM}. Our goals are to explore the physical conditions in and distribution of such gas, as well as to explore the nature of the interfaces between the hot ISM and the other interstellar gas phases. The observations completed with no reported problems.
1.8 Completed Two Sets of STIS/CCD 8674 (Coronographic Imaging Of Old PMS Stars)
The Space telescope Imaging Spectrograph (CCD) was used to to investigate the missing link between MS and young stars CS environments by searching for second generation disks of dust or gas around the few known old PMS stars and by modeling their CS environments. Our
HST/NICMOS images revealed a disk around HD141569, and possibly also {but still to be confirmed} around HD100546 and HD135344. We propose here to use the unprecedented detection capabilities of STIS to get high signal-to-noise {SN} images of HD141569 and HD135344. This will allow to study in much more detail the HD141569 disk, to confirm or infirm the other disk, and to perform fine modeling of the CS dust. The proposal completed with no reported problems.
1.9 Completed Four Sets of STIS/CCD 8853 (Residual Images after Saturation, Cycle 9)
The Space Telescope Imaging Spectrograph (CCD) was used to measure the residual effect of over-illumination of the CCD as a function of color {UV vs. RED}. There was no reported anomalous activity.
1.10 Completed Two Sets of STIS/CCD 8631 (Bright Quasar Close Lensing Search II)
The Space Telescope Imaging Spectrograph (CCD) was used to expand the Cycle 8 second generation HST snapshot survey of bright quasars, optimized to find lenses with component image separations < 1". The observations completed nominally.
1.11 Completed Three Sets of STIS/CCD 8437 (Dark Monitor-Part 2 C8)
The Space Telescope Imaging Spectrograph (CCD) was used to monitor the darks. The proposal completed nominally.
1.12 Completed WF/PC-2 8660 (Saturn’s Rings and Small Moons)
The Wf/PC-2 was used to investigate the composition, structure, and particle properties of the rings from variations of ring brightness and color with radius, tilt and phase angle, to measure the azimuthal asymmetry of the A ring of Saturn and the temporal variability of the clumpy F ring, to follow the enigmatic behavior of the renegade satellites Prometheus and Pandora, and to observe the co-orbital satellites Janus and Epimetheus as they exchange orbits in February 2002. The observations completed nominally.
1.13 Complete WF/PC-2 8331 (Probing the Dark Side of Galaxy Formation: HST Imaging of the ISO Ultradeep Survey)
The WF/PC-2 was used to observe the Hubble Deep Field (HDF) which gave astronomers an unprecedented view of the optical and rest–frame–UV side of galaxy formation. However,
new data from ISO and COBE confirms the suspicion that the optical/UV does not tell the whole story. ISO observations have also demonstrated that this is true even in the HDF. These show the presence of ~25 galaxies brighter than ~200MuJy at 15Mum. The observations were completed with no reported anomalies.
1.14 Completed STIS/CCD 8808 (POMS Test Proposal: STIS Non-Scripted Parallel Proposal Continuation III)
The Space Telescope Imaging Spectrograph (CCD) was used to make non-scripted, parallel observations as part of a POMS test proposal. The observations completed with no anomalous activity.
1.15 Completed STIS/CCD 8870 (POMS Test Proposal: STIS Non-Scripted Parallel Proposal Continuation IV)
The Space Telescope Imaging Spectrograph (CCD) was used to make non-scripted, parallel observations as part of a POMS test proposal. The observations completed with no anomalous activity
1.16 Completed STIS/CCD/MA1 8606 (Determining the Nature of the Variable Absorption in AGN: Monitoring NGC 3783 with HST And Chandra)
The Space Telescope Imaging Spectrograph (CCD and MA1) was used to investigate Seyfert 1 galaxies, many of which show intrinsic UV absorption lines, characterized by high moderate widths, significant outflow velocities, and variability on time scales as small as days. Seyferts with UV absorption also show variable X-ray “warm absorbers”, characterized by O VII and O VIII absorption edges, which suggests a common
origin. Variability monitoring is the key to understanding the absorbers, by providing their radial locations, densities, and evolution in ionization, column density, velocity, and coverage of the inner active nucleus. The proposal completed with no problems.
1.17 Completed Three Sets of STIS/MA2 8430 (STIS MAMA Dipsersion Solution Check)
The Space Telescope Imaging Spectrograph (MA2) was used to perform a wavelength dispersion observation which is determined on a yearly basis {2x in Cycle 8} as part of a long-term monitoring program. The observations were completed as planned, and no anomalies were reported.
1.18 Completed Three Sets of WF/PC-2 8876 (Does Comet Linear Have a Nucleus?)
The WF/PC-2 was used to observe the nucleus of Comet Linear {C/1999 S4} that has reportedly disintegrated into a cloud of dust during the past week {Kidger, IAUC 7467, 27 July
2000}. While there is little doubt that a major disruption event took place recently, a major unresolved issue is whether the comet left behind a remnant nucleus of significant size. HST target-of-opportunity observations at the predicted position of this remnant would yield the most sensitive estimate possible for the size of any remaining large object and would provide important new insights into the structure of cometary nuclei and the mechanism by which they fragment. The observation completed with no reported problems.
1.19 Completed WF/PC-2 8699 (The Origin of Short-Period Comets)
The WF/PC-2 was used to detect and characterize cometary nuclei in order to determine the basic physical properties of a large fraction of the population of short-period comets. By acquiring statistically significant data, we can study the origin of this family of comets and test the hypothesis that they are collisional fragments from the Kuiper Belt Objects. The observations completed with no reported problems.
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During the second iteration of WF/PC-2 8699 (The Origin of Short-Period Comets), the entry into PSEA occurred and some observations were affected.
The followed scheduled observations were no executed due to the entry into PSEA:
One Iteration of WF/PC-2 8826 (Cycle 9 Supplemental Darks pt 1) One Iteration of STIS/CCD 8439 (Bias Monitor-Part 2 C8) Three Iterations pf WF/PC-2 8805 (POMS Test Proposal: WFII Parallel Archive
Proposal Continuation)
Two Iterations of STIS/CCD 8437 (Dark Monitor-Part 2 C8) Four Iterations of STIS/CCD 8808 (POMS Test Proposal: STIS Non-Scripted
Parallel Proposal Continuation III)
Two Sets of STIS/CCD 8258 (A Search for Kuiper Belt Object Satellites) WF/PC-2 8338 (The Evolution of the Host Galaxies of Powerful Radio Sources)
WF/PC-2 8604 (Stellar Populations Across the Small Magellanic Cloud (SMC) :
History and Structure)
STIS/CCD 7912 (STIS Parallel Archive Proposal – Nearby Galaxies – Imaging and
Spectroscopy)
Two Sets of STIS/CCD 8663 (Survey of SMC Planetary Nebulae: Nebular and
Stellar Evolution in a Low- Metallicity Environment)
STIS/CCD 8854 (Sparse-Field CTE External C9)
WF/PC-2 8059 (POMS Test Proposal: Targeted Parallel Archive Proposal) WF/PC-2 8544 (POMS Test Proposal: WFII Backup Parallel Archive Proposal II)
STIS/CCD/MA1/MA2 8422 (Imaging Sensitivity and PSF Library C8) WF/PC-2 8632 (A UV Atlas of Nearby Galaxies)
WF/PC-2 8250 (Proper Motions of Bulge Stars)
Two Sets of STIS/CCD 8840 (Read Noise Monitor)
FGS 8729 (Speedy Gonzales Mass Determinations: Fast Orbiting Red Dwarf Systems)
2.0 FLIGHT OPERATIONS SUMMARY:
2.1 Guide Star Acquisitions:
Scheduled Acquisitions: 17
Successful: 17
Scheduled Re-acquisitions: 10
Successful: 10
2.2 FHST Updates:
Scheduled: 43
Successful: 43
2.3 Operations Notes:
Using ROP SR-1A, the SSR EDAC error counter was cleared eight times.
Per ROP DF-18A, the engineering status buffer limits were adjusted four times.
486 dumps were performed seven times as directed by ROP DF-1A.
ROPs IC-1 and IC-2 were utilized seven times to manage the SSA and MA transmitters.
As documented in HSTAR 7769, EDAC errors were encountered in the area 1100-5000 during a playback at 217/221415Z. A re-playback, the same errors occurred.
Three TTRs were written for IONET dropouts occurring on days 218 and 219.
The SSR pointer was set at 218/0808Z per ROP SR-3.
All iterations of the target of opportunity proposal, detailed in 1.18 above, were executed with no reported problems.
At 218/170654Z, the HST entered hardware sunpoint safemode, switching control of the vehicle from the 486 computer to the Pointing Safemode Electronics Assembly (PSEA). HSTAR 7772 was written. Mission Operations were quickly able to trace the problem to a procedural error that occurred during a dump of the 486 memory that was performed in preparation for an update of the EEPROM in the 486 (planned for next week). The address range specified in the dump procedure included an area that, by design, produces parity errors when read. It was the failure of the safemode test that monitors parity errors that initiated the hardware sunpoint. (The HSTAR points out that neither ROP DF-1A nor the CCL contained checks to avoid dumping this range.) The HST remained power positive and the aperture door remained open. During PSEA control, the K61 charge current controller relay, which had failed in a non-closed position in November 1999, connected. Solar array section 6 output current and battery 6 charge current verified that the +CC and +DD array panels allowed current to flow through the K61 relay. The reason for the K61 "recovery" is under investigation. During the recovery of the NSSC-1 from fixed format to normal mode, the commands to enable the FOC AP12 (RIU telemetry collection processor) and to load the science data formats (group command ZXFMT) were skipped. (HSTARs 7773 and 7774 were written. Analysis shows these anomalies were caused by the CCL not waiting for telemetry to update before continuing. FOC AP12 was enabled and the science data formats were loaded at a later time. Operations personnel transitioned to a Health and Safety SMS at 219/1000Z that remained in effect until 2220/0000Z when a normal science load was resumed. The HST reached trickle charge on the first orbit of the Health and Safety SMS. All subsystems are performing nominally.
The NSSC-1 status buffer was dumped at 219/1123Z as directed by ROP NS-3.
Using ROP NS-5, SI C&DH errors were reset at 219/1907Z.
Science resumed at 220/0029Z with the WF/PC-2 Crab Nebula Pulsar proposal (described in the next report).
As documented in HSTAR 7775, the Solar Array normal cosine 1 (QSANCOS1) flagged out-of-limits high with a value of 1 at 220/072618Z and again at 220/072906Z for one 12-second sample.
3.0 SIGNIFICANT FORTHCOMING EVENTS:
Continuation of normal science observations and calibrations.
